Associations Between Maternal Abortion History and Neonatal Outcome among Very Preterm Infants：a multicenter cohort study

Associations Between Maternal Abortion History and Neonatal Outcome among Very Preterm Infants：a multicenter cohort study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Associations Between Maternal Abortion History and Neonatal Outcome among Very Preterm Infants：a multicenter cohort study Min Yang, Jie Yang, Dianna Wang, Jiale Dai, Xiaobo Fan, Yun Cao, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4941021/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 06 Oct, 2025 Read the published version in BMC Pregnancy and Childbirth → Version 1 posted 12 You are reading this latest preprint version Abstract Background It is unclear whether there is an association between maternal abortion history and neonatal outcomes of singleton very preterm infants (VPIs). We assess the association between maternal abortion history and neonatal outcome of VPIs in China. Methods All first parity singleton VPIs born at < 32 weeks gestational age (GA) who were admitted to neonatal intensive care units (NICU) participating in the Chinese Neonatal Network (CHNN) from 2019 to 2021 were included in the study. Multivariable logistic regression models were constructed to compare neonatal outcomes among infants with different maternal abortion histories after adjusting for confounders. Results A total of 7256 VPIs were included in this analysis. Overall, 3133 (43.2%) infants had positive maternal abortion history. The incidence of mortality or any major morbidity including respiratory distress syndrome (RDS), patent ductus arteriosus (PDA), intraventricular haemorrhage (IVH), IVH stage 3 or 4, moderate or severe bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), ROP stage 3, 4, or 5 tended to increase significantly with increasing number of maternal abortion histories from non-abortion group to ≥2 abortions group. Multivariable analysis showed that maternal abortion history was significantly associated with higher risks of mortality or any major morbidity (adjusted odds ratio [aOR] 1.15, 95% confidence interval [CI] 1.03–1.29), RDS (aOR 1.22, 95%CI 1.08–1.38), IVH (aOR 1.17, 95% CI 1.05–1.31), and IVH stage 3 or 4 (aOR 1.27, 95% CI 1.01–1.59). Risk increased with the number of abortions. VPIs of mothers with two or more abortions had the highest risk of mortality or any major morbidity (aOR 1.18, 95% CI 1.02–1.36), RDS (aOR 1.35, 95% CI 1.18–1.56), IVH (aOR 1.23, 95% CI 1.07–1.43) and moderate or severe BPD (aOR 1.17, 95% CI 1.01–1.36), compared to the non-abortion group. Conclusions In China, VPIs born to mothers with previous abortion history may have a greater risk of adverse outcomes. Based on the potential impact of maternal abortion history on newborns, it is necessary to provide additional information on related risks during antenatal counseling for these mothers. Abortion Neonatal outcome Singletons Mortality Morbidity Figures Figure 1 Background Despite improvements in maternal nutrition, prenatal care, and the treatment of maternal infections, global data from 166 countries shows that the global abortion rate was approximately 36–44 per 1,000 women aged 15–49 years between 1990 and 2019 [ 1 ]. This includes both induced and spontaneous abortions, with spontaneous abortion being the most common complication of pregnancy, accounting for approximately 30% of all pregnancies. The rates of induced abortions vary across countries and regions. In China, the definition of abortion during pregnancy was established in 2020, stating that pregnancies terminated before 28 weeks’ gestation and with fetuses weighing less than 1,000 grams are classified as abortions [ 2 ]. China has a high number of induced abortions [ 3 ]. In 2019, the documented number of induced abortions in China was 9.76 million [ 4 ], while the estimated actual number per year is around 13 million [ 5 ]. Considering the underreporting and concealment of induced abortions occurring in private hospitals and clinics in China, the actual number is likely to be higher. Over the past five years, the annual total of induced abortions in China has remained at approximately 9.5 million [ 6 ]. It is well established that maternal previous history of abortions, particularly with one or multiple previous miscarriages, is associated with an increased risk of preterm birth [ 7 ]. It is also associated with a higher risk of obstetric complications, such as need for cesarean section, gestational diabetes, preterm birth, stillbirth, low birth weight, neonatal admission, and mortality in subsequent pregnancies [ 8 – 14 ]. It has been confirmed that induced abortion by vacuum aspiration is associated with an increased risk of first-trimester miscarriage in the subsequent pregnancies [ 15 ]. This raises the question of whether these histories of spontaneous or induced abortions have adverse effects on very preterm infants. This potentially can have significant implications for public health. Unfortunately, there have been limited studies assessing the association between previous maternal abortion history and neonatal outcomes, particularly for very preterm infants. Some studies have found an association between miscarriage history in primiparous women and adverse pregnancy outcomes including intrauterine fetal death and perinatal loss in subsequent pregnancies, although these studies had small sample sizes [ 9 , 16 ]. There were also reports suggesting that induced abortion is not an independent risk factor for adverse obstetric outcome [ 17 ]. Our study aims to investigate whether maternal abortion history is associated with an increased risk of adverse neonatal outcome in subsequent pregnancies among VPIs in China. Methods Study Design and Data Source This retrospective cohort was based on the database of the Chinese Neonatal Network (CHNN) which prospectively collected data between January 1, 2019 and December 31, 2021. The CHNN was established in 2018 and is comprised of four national and four regional children's medical centers, as well as thirty provincial perinatal and children's medical centers across China. The number of participating hospitals in the CHNN has increased from 58 in 2019 to 70 in 2020 and 79 in 2021. All CHNN participating hospitals specialize in neonatal care and are recognized for their expertise in managing high-risk newborns. These hospitals were from national and regional children's hospitals, provincial perinatal and children's medical centers, as well as major referral centers in large cities representing approximately 5% of all VPIs in China [ 18 ]. A standardized clinical database was implemented to monitor outcomes and care practices in the CHNN's neonatal intensive care units (NICUs). Trained abstractors utilized a standardized manual of variable definitions to collect data from NICU electronic medical records. During data entry into a customized database, an error-checking mechanism was implemented. Subsequently, the data were electronically submitted to the CHNN coordinating center at the Children's Hospital of Fudan University, ensuring patient anonymity. Investigators at each site were responsible for ensuring data accuracy and maintaining rigorous quality control procedures throughout the entire process [ 19 ]. Study Population The study included all first parity singleton very preterm infants (VPIs) born at a gestational age of less than 32 weeks who were admitted to NICUs within 24 hours of birth and were part of the CHNN from 2019 to 2021. Infants with major congenital anomalies, those conceived through assisted reproductive technology (ART), transferred to other hospitals, without prenatal visits, with missing gravidity or parity information, and multiple pregnancies were excluded from the study. Exposure Abortion is defined as the loss of a pregnancy before 28 weeks of gestation. The study population was divided into two groups based on whether the VPIs had a history of maternal abortion: the abortion group and the non-abortion group. The abortion group was further categorized into two subgroups: the 1-abortion group and the ≥ 2 abortions group, based on the number of previous maternal abortions. Transfers and readmissions between participating hospitals were tracked as data for the same infants. VPIs who were stillborn, died in the delivery room, or were transferred to non-participating hospitals within 24 hours of birth were not included in the database. Outcomes and Definitions The primary outcome was mortality or any major morbidity. Any major morbidity was defined as early-onset sepsis, late-onset sepsis, retinopathy of prematurity (ROP) stage3, 4 or 5, moderate or severe bronchopulmonary dysplasia (BPD), cystic periventricular leukomalacia (cPVL), intraventricular haemorrhage (IVH) grade 3 or 4 and necrotizing enterocolitis (NEC) stage 2 or 3. Early-onset sepsis was defined as a positive blood or cerebrospinal fluid culture and antibiotic therapy with onset 3 days. ROP stage 3, 4 or 5 was defined according to the international classification of ROP [ 21 ]. BPD was defined as a requirement for respiratory support at 36 weeks postmenstrual age or at discharge/transfer/death if before 36 weeks postmenstrual age [ 22 ]. cPVL was defined as the presence of periventricular cysts on cranial ultrasound or MRI. IVH grade 3 or 4 was defined according to Papile’s criteria [ 23 ]. NEC was defined according to Bell’s criteria [ 24 , 25 ]. In-hospital mortality was defined the death of infants during hospitalisation. Early death was defined as death occurring less than 7 days after birth. PDA was diagnosed by cardiac ultrasound. RDS was defined according to a combination of clinical signs and symptoms, laboratory analysis and chest X-ray (CXR) [ 26 ]. Definitions of other covariates We determined the gestational age (GA) by utilizing a hierarchical approach that involved the best obstetric estimate derived from antenatal ultrasound, menstrual history, obstetric examination, or a combination of these methods. In cases where the obstetric estimate was unavailable or differed from the postnatal estimate by more than two weeks, we estimated the gestational age using the Ballard score [ 27 ]. Small for gestational age (SGA) was defined as a birth weight below the 10th percentile for the corresponding gestational age, based on the Chinese neonatal birth weight values [ 28 ]. Chorioamnionitis encompassed both clinical chorioamnionitis and histopathological chorioamnionitis. Clinical chorioamnionitis was diagnosed by maternal fever alone (> 39.0°C), or with a temperature of 38.0-38.9°C that persists after 30 minutes and one additional clinical sign of infection such as maternal leukocytosis, purulent cervical discharge or fetal tachycardia [ 29 ]. Histopathological chorioamnionitis was defined as the presence of diffuse neutrophil infiltration into the chorioamniotic membranes [ 30 ]. Diabetes and hypertension diagnoses were based on corresponding disease criteria and measurements obtained during the follow-up period [ 31 , 32 ]. Inborn referred to infants born in a maternity ward located at the same site as the NICU. Ethics Approval This study received approval from the Ethics Committee of the Children's Hospital of Fudan University (identifier: 2018 − 296) and was acknowledged by all participating NICUs for the development, compilation, data transfer, hosting, and analysis of the CHNN dataset. Due to the retrospective nature of the analysis and the absence of direct intervention in the diagnosis and treatment of individual patients, individual consent for this study was waived in all 79 tertiary-level NICUs. The study was conducted in accordance with the principles outlined in the Declaration of Helsinki (revised 2013). Statistical analysis Maternal and neonatal characteristics were compared between abortion and non-abortion groups. Frequencies (percentages) and medians (interquartile range [IQR]) were reported for categorical and continuous variables, respectively. Difference was assessed by Chi-square test for categorical variables and Wilcoxon rank test for continuous variables. Also subgroup comparison (1 abortion group vs. ≥2 abortions group) of abortion group was conducted. Neonatal outcomes were compared between abortion and non-abortion groups. Frequencies (percentages) were reported and difference was assessed by Chi-square test. Furthermore, the abortion group was divided into 1 abortion group and ≥2 abortions group. Cochran-Armitage test was used to assess the trend of outcomes across non-abortion group, 1 abortion group and ≥2 abortions group. Univariate and multivariate logistic regressions were applied for neonatal outcomes. Odds ratios (95% confidence intervals) were estimated. All analysis was conducted by SAS 9.4 (SAS Institute, Cary, NC) with two-sided significance level 0.05. Results Study Population During the study period, 12518 infants were first parity singleton VPIs admitted within 24hr after birth. Among them, 1730 infants were from multiple birth, 412 infants had no prenatal visit and 1 infant had no gravidity or parity information, 119 infants had major congenital anomalies, 467 infants were transferred to other hospital and 2533 infants conceived with assisted reproductive technology were excluded. As a result, 7256 first parity singleton VPIs were included in this study. Of these, 3133 (43.2%) infants had positive maternal abortion history (Fig. 1 ). The gestational age and birth weight of the abortion group were significantly lower than those of the non-abortion group. The median (P25, P75) gestational age of the abortion group and the non-abortion group were 29.9 (28.4, 31.0) and 30.0 (28.7, 31.0), respectively. The median (P25, P75) birth weight of abortion group and non-abortion group were 1280.0 (1050.0, 1500.0) and 1310.0 (1100.0, 1530.0), respectively. The abortion group was significantly more likely to have antenatal steroid usage (80.8% vs. 78.4%, P < 0.01), have antenatal magnesium sulphate therapy(58.3% vs. 54.3%, P < 0.01), were born to mothers with diabetes (20.0% vs. 16.3%, P < 0.01), were born to mothers with hypertension (26.7% vs. 22.0%, P < 0.01), were delivered by caesarean delivery (C-section) (58.4% vs. 50.6%, P < 0.01), and were inborn (80.7% vs. 78.4%, P < 0.01) than non-abortion group. Significant differences were found among non-abortion, 1 abortion and ≥ 2 abortions groups in maternal age, antenatal steroids, diabetes, hypertension, cesarean delivery, antenatal magnesium sulfate therapy, male, gestational age, birth weight, apgar score at 1 minute, and inborn ( P < 0.01) (Table 1 ). Table 1 Descriptive characteristics and outcomes in relation to the number of previous maternal abortions among VPIs Characteristics Abortion group (N = 3133) P value a Number of previous abortions P value b Non-abortion group (N = 4123) 1 (N = 1722) ≥2 (N = 1411) N(%) 4123/7256(56.8) 3133/7256(43.2) 1722/7256(23.7) 1411/7256(19.5) Mother Maternal age, years, median(P25, P75) 28(26,31) 30(28,34) < 0.01 30(27,32) 32(29,35) < 0.01 antenatal steroids 3124/3987(78.4) 2452/3035(80.8) 0.01 1318/1667(79.1) 1134/1368(82.9) < 0.01 Diabetes 667/4102(16.3) 624/3116(20.0) < 0.01 318/1713(18.6) 306/1403(21.8) < 0.01 Hypertension 904/4103(22.0) 834/3123(26.7) < 0.01 456/1716(26.6) 378/1407(26.9) 24h 1022/3994(25.6) 716/3034(23.6) 0.06 383/1670(22.9) 333/1364(24.4) 0.10 Cesarean delivery 2081/4115(50.6) 1827/3128(58.4) < 0.01 754/1718(43.9) 547/1410(38.8) < 0.01 Chorioamnionitis 563/3241(17.4) 426/2480(17.2) 0.85 220/1351(16.3) 206/1129(18.3) 0.43 Antenatal magnesium sulphate therapy 2065/3806(54.3) 1689/2895(58.3) < 0.01 884/1580(56.0) 805/1315(61.2) < 0.01 Infant Male 2345/4120(56.9) 1639/3126(52.4) < 0.01 913/1720(53.1) 726/1406(51.6) < 0.01 Gestational age, weeks, median (P25, P75) 30.0 (28.7,31.0) 29.9 (28.4,31.0) < 0.01 30.0 (28.6,31.0) 29.7 (28.1,31.0) < 0.01 Birth weight, grams, median (P25, P75) 1310.0 (1100.0,1530.0) 1280.0 (1050.0,1500.0) < 0.01 1290.0 (1065.0,1500.0) 1260.0 (1030.0,1500.0) < 0.01 Small for gestational age 331/4111(8.1) 293/3112(9.4) 0.04 162/1708(9.5) 131/1404(9.3) 0.12 Apgar score (1-min) < 0.01 < 0.01 0–3 229/4058(5.6) 220/3095(7.1) 113/1692(6.7) 107/1403(7.6) 4–6 683/4058(16.6) 593/3095(19.2) 298/1692(17.6) 295/1403(21.0) 7–10 3146/4058(77.5) 2282/3095(73.7) 1281/1692(75.7) 1001/1403(71.4) Apgar score (5-min) 0.07 0.09 0–3 46/3945(1.2) 50/3035(1.7) 26/1654(1.6) 24/1381(1.7) 4–6 197/3945(5.0) 176/3035(5.8) 86/1654(5.2) 90/1381(6.5) 7–10 3702/3945(93.8) 2809/3035(92.6) 1542/1654(93.2) 1267/1381(91.8) Inborn 3231/4123(78.4) 2528/3133(80.7) 0.02 1345/1722(78.1) 1183/1411(83.8) < 0.01 Abbreviations: PROM, premature rupture of membranes. a P values refer to comparisons between abortion group and non-abortion group. b P values refer to comparisons across non-abortion group, 1 abortion group and ≥2 abortions group. The trend of neonatal outcomes among the non-abortion group, 1 abortion group, and ≥ 2 abortions group The abortion group was significantly more likely to have mortality or any major morbidity (44.7% vs. 40.8%, P < 0.01), RDS (55.4% vs. 48.2%, P < 0.01), PDA (50.1% vs. 47.4%, P = 0.02), NEC stage 2 or 3 (5.2% vs. 4.2%, P = 0.04), IVH (38.7% vs. 35.7%, P = 0.01), IVH grade 3 or 4 (6.2% vs. 4.8%, P = 0.01), moderate or severe BPD (36.6% vs. 33.2%, P < 0.01), ROP (26.6% vs. 22.3%, P < 0.01), and ROP stage 3, 4, 5 (3.5% vs. 2.5%, P = 0.03) than non-abortion group. We categorized the abortion group into two subgroups: 1 abortion and ≥ 2 abortions group. The incidence of mortality or any major morbidity ( P < 0.01), respiratory distress syndrome (RDS) ( P < 0.01), patent ductus arteriosus (PDA) ( P = 0.01), intraventricular haemorrhage (IVH) ( P < 0.01), IVH stage 3 or 4 ( P = 0.04), moderate or severe bronchopulmonary dysplasia (BPD) ( P < 0.01), retinopathy of prematurity (ROP) ( P < 0.01), ROP stage 3, 4, or 5 ( P = 0.03) tended to increase significantly with increasing number of maternal abortion histories across non-abortion group, 1 abortion and ≥2 abortions group (Table 2 ). Table 2 Crude percentage of neonatal outcome according to the number of previous maternal abortions among VPIs P value d Number of previous abortions P- trend e Outcome, n/N (%) Non-abortion group Abortion group 1 ≥2 Mortality or any major morbidity a 1681/4123(40.8) 1400/3133(44.7) < 0.01 739/1722(42.9) 661/1411(46.9) < 0.01 Mortality 477/4123(11.6) 371/3133(11.8) 0.72 192/1722(11.2) 179/1411(12.7) 0.38 In-hospital mortality 139/3595(3.9) 121/2737(4.4) 0.27 61/1509(4.0) 60/1228(4.9) 0.14 Early death 81/3923(2.1) 69/2966(2.3) 0.46 35/1617(2.2) 34/1349(2.5) 0.35 RDS 1989/4123(48.2) 1734/3133(55.4) < 0.01 911/1722(52.9) 823/1411(58.3) < 0.01 PDA 1893/3997(47.4) 1522/3040(50.1) 0.02 819/1665(49.2) 703/1375(51.1) 0.01 NEC stage 2 or 3 173/4123(4.2) 163/3133(5.2) 0.04 92/1722(5.3) 71/1411(5.0) 0.10 IVH b 1329/3725(35.7) 1101/2843(38.7) 0.01 593/1560(38.0) 508/1283(39.6) < 0.01 IVH grade 3 or 4 b 199/4123(4.8) 194/3133(6.2) 0.01 110/1722(6.4) 84/1411(6.0) 0.04 cPVL b 168/3710(4.5) 134/2829(4.7) 0.69 70/1555(4.5) 64/1274(5.0) 0.53 Early-onset sepsis 48/4123(1.2) 41/3133(1.3) 0.58 20/1722(1.2) 21/1411(1.5) 0.40 Late-onset sepsis 308/4123(7.5) 239/3133(7.6) 0.80 129/1722(7.5) 110/1411(7.8) 0.72 Moderate or severe BPD 1370/4123(33.2) 1145/3133(36.6) < 0.01 599/1722(34.8) 546/1411(38.7) < 0.01 ROP c 723/3249(22.3) 654/2462(26.6) < 0.01 363/1361(26.7) 291/1101(26.4) < 0.01 ROP stage 3, 4, or 5 c 80/3249(2.5) 85/2460(3.5) 0.03 46/1361(3.4) 39/1101(3.5) 0.03 Abbreviations: NEC, necrotizing enterocolitis; BPD, bronchopulmonary dysplasia; IVH, intraventricular hemorrhage; PVL, periventricular leucomalacia; ROP, retinopathy of prematurity; RDS, respiratory distress syndrome; PDA, patent ductus arteriosus. a Any major morbidity included early-onset sepsis, late-onset sepsis, ROP stage3, 4 or 5, moderate or severe BPD, cPVL, IVH grade 3 or 4 and NEC stage 2 or 3. b Incidence of IVH grade 3 or 4 and cPVL were calculated within Infants who had neuroimaging results. c Incidence of ROP and ROP stage 3, 4 or 5 were calculated among infants with eye examinations in the NICU. d P values refer to comparisons between abortion group and non-abortion group. e Test for trend based on variable across non-abortion group, 1 abortion group and ≥2 abortions group. Impact of maternal abortion history on neonatal outcomes After adjusting for potential confounders, overall the abortion group had higher odds of mortality or any major morbidity (adjusted odds ratio [OR] 1.15, 95% confidence interval [CI] 1.03–1.29), RDS (aOR 1.22, 95% CI 1.08–1.38), IVH (aOR 1.17, 95% CI 1.05–1.31), IVH grade 3 or 4 (aOR 1.27, 95% CI 1.01–1.59), compared to the non-abortion group. The impact of maternal abortion history on neonatal outcomes is more significant for mothers with two or more abortions compared to mothers with one abortion. VPIs of mothers with two or more abortions had the higher risk of mortality or any major morbidity (aOR 1.18, 95% CI 1.02–1.36), RDS (aOR 1.35, 95% CI 1.18–1.56), IVH (aOR 1.23, 95% CI 1.07–1.43) and moderate or severe BPD (aOR 1.17, 95% CI 1.01–1.36), compared to the non-abortion group. While VPIs of mothers with one abortion had the highest risk of RDS (aOR 1.15, 95% CI 1.01–1.30), IVH grade 3 or 4 (aOR 1.38, 95% CI 1.07–1.80) compared to the non-abortion group (Table 3 ). Table 3. Odds ratios for the association between previous abortion history and the risk of neonatal outcome among VPIs according to the number of previous abortions Outcome Unadjusted OR(95% CI) Adjusted OR(95%CI) Abortion group b Number of previous abortions Abortion group b,c Number of previous abortions 1 b ³2 b 1 b,c ³2 b,c Mortality or any major morbidity a 1.20(1.09,1.32) 1.12(1.00,1.26) 1.28(1.13,1.44) 1.15(1.03,1.29) 1.08(0.95,1.23) 1.18(1.02,1.36) Mortality 1.02(0.89,1.18) 0.96(0.80,1.15) 1.11(0.92,1.33) 0.93(0.78,1.10) 0.84(0.67,1.03) 1.00(0.80,1.24) In-hospital mortality 1.15(0.90,1.49) 1.05(0.77,1.42) 1.28(0.94,1.74) 0.93(0.70,1.25) 0.88(0.62,1.26) 0.92(0.63,1.33) Early death 1.15(0.83,1.61) 1.05(0.70,1.57) 1.23(0.82,1.84) 1.00(0.69,1.46) 0.98(0.62,1.53) 0.87(0.55,1.40) RDS 1.33(1.22,1.47) 1.21(1.08,1.35) 1.50(1.33,1.70) 1.22(1.08,1.38) 1.15(1.01,1.30) 1.35(1.18,1.56) PDA 1.12(1.02,1.23) 1.08(0.96,1.21) 1.16(1.03,1.32) 1.00(0.90,1.11) 0.98(0.86,1.11) 1.07(0.94,1.23) NEC stage 2 or 3 1.26(1.01,1.56) 1.29(0.99,1.67) 1.21(0.91,1.61) 1.24(0.97,1.58) 1.30(0.98,1.72) 1.16(0.85,1.59) IVH 1.14(1.03,1.26) 1.11(0.98,1.25) 1.18(1.04,1.35) 1.17(1.05,1.31) 1.13(0.99,1.29) 1.23(1.07,1.43) IVH grade 3 or 4 1.30(1.06,1.59) 1.35(1.06,1.71) 1.25(0.96,1.62) 1.27(1.01,1.59) 1.38(1.07,1.80) 1.14(0.85,1.53) cPVL 1.04(0.83,1.32) 0.99(0.75,1.32) 1.12(0.83,1.50) 1.01(0.78,1.30) 0.94(0.69,1.28) 1.14(0.82,1.57) Early-onset sepsis 1.13(0.74,1.71) 0.10(0.59,1.69) 1.28(0.77,2.15) 1.00(0.63,1.58) 0.97(0.55,1.68) 0.99(0.55,1.77) Late-onset sepsis 1.02(0.86,1.22) 1.00(0.81,1.24) 1.05(0.84,1.31) 0.96(0.79,1.17) 0.93(0.74,1.18) 0.94(0.74,1.21) Moderate or severe BPD 1.15(1.05,1.27) 1.07(0.95,1.21) 1.27(1.12,1.44) 1.09(0.97,1.22) 1.00(0.87,1.15) 1.17(1.01,1.36) ROP 1.26(1.12,1.42) 1.27(1.10,1.47) 1.26(1.07,1.47) 1.06(0.92,1.22) 1.10(0.93,1.30) 1.00(0.83,1.21) ROP stage 3, 4, or 5 1.42(1.04,1.93) 1.39(0.96,2.00) 1.46(0.99,2.15) 1.10(0.77,1.56) 1.17(0.78,1.76) 1.01(0.65,1.58) Abbreviations: NEC, necrotizing enterocolitis; BPD, bronchopulmonary dysplasia; IVH, intraventricular hemorrhage; PVL, periventricular leucomalacia; ROP, retinopathy of prematurity; RDS, respiratory distress syndrome; PDA, patent ductus arteriosus, OR, odds ratios; CI, confidence interval. a Any major morbidity included early-onset sepsis, late-onset sepsis, ROP stage3, 4 or 5, moderate or severe BPD, cPVL, IVH stage 3 or 4 and NEC stage 2 or 3. b Non-abortion group was the reference group. c Adjusted for maternal age, antenatal steroid usage, hypertension, diabetics, gestational age, small for gestational age, antenatal magnesium sulphate therapy, sex, delivery mode, inborn. We treated maternal abortion history as a continuous variable and analyzed its association with neonatal outcomes. The results showed VPIs of mothers with abortion history had higher risk of mortality or any major morbidity (aOR 1.07, 95% CI 1.02–1.13), RDS (aOR 1.14, 95% CI 1.09–1.20), IVH (aOR 1.07, 95% CI 1.02–1.13) and moderate or severe BPD (aOR 1.05, 95% CI 1.00-1.11), compared to the non-abortion group (Table 4 ). Table 4 Crude OR and adjusted OR with each additional number of abortion of neonatal outcome Outcome Unadjusted OR(95% CI) a Adjusted OR(95%CI) a,b Mortality or any major morbidity 1.08(1.03,1.12) 1.07(1.02,1.13) Mortality 1.02(0.95–1.08) 0.99(0.91,1.07) In-hospital mortality 1.06(0.96–1.18) 0.97(0.86–1.11) Early death 1,05(0.91–1.20) 0.96(0.82,1.13) RDS 1.16(1.11–1.21) 1.14(1.09,1.20) PDA 1.05(1.01–1.10) 1.01(0.96,1.06) NEC stage 2 or 3 1.07(0.97–1.17) 1.06(0.95,1.17) IVH 1.05(1.01–1.10) 1.07(1.02,1.13) IVH grade 3 or 4 1.04(0.95–1.13) 1.01(0.91,1.12) cPVL 1.00(0.90–1.11) 0.98(0.87,1.11) Early-onset sepsis 1.12(0.95–1.33) 1.03(0.85,1.26) Late-onset sepsis 1.00(0.93–1.09) 0.99(0.90,1.08) Moderate or severe BPD 1.07(1.02–1.11) 1.05(1.00,1.11) ROP 1.08(1.02–1.14) 0.99(0.93,1.06) ROP stage 3, 4, or 5 1.17(1.04–1.32) 1.05(0.91,1.21) Abbreviations: NEC, necrotizing enterocolitis; BPD, bronchopulmonary dysplasia; IVH, intraventricular hemorrhage; PVL, periventricular leucomalacia; ROP, retinopathy of prematurity; RDS, respiratory distress syndrome; PDA, patent ductus arteriosus, OR, odds ratios; CI, confidence interval. a Non-abortion group was the reference group. b Number of previous abortions was treated as a continuous variable, and adjusted for maternal age, antenatal steroid usage, hypertension, diabetics, gestational age, small for gestational age, antenatal magnesium sulphate therapy, sex, delivery mode, inborn. Discussion Principal findings This national-level study analyzed 12518 very preterm infants (VPIs) admitted to 57 Chinese tertiary NICUs from January 2019 to December 2021. It aimed to address the knowledge gap in neonatal perinatal characteristics and outcomes between abortion and non-abortion groups in VPIs. The major finding of our study was that the abortion group had more adverse neonatal outcomes. Whereas some previous studies have focused on the obstetrics outcomes and the risk of further miscarriage in women with previous abortions [ 8 – 12 , 33 ]. Interestingly, in the univariate analysis, we found a significant association between maternal abortion history and several adverse neonatal outcomes. However, after adjusting for confounding factors such as maternal age, antenatal steroid usage, hypertension, diabetes, gestational age, small for gestational age, antenatal magnesium sulfate therapy, sex, delivery mode, and inborn status, many of these associations disappeared. Comparing the abortion group to the non-abortion group, as well as to the groups with one or more than two abortions, we observed a significantly increased risk of mortality or any major morbidity, RDS, IVH, and moderate or severe BPD among neonates with maternal abortion history in VPIs. Maternal characteristics Our finding revealed that abortion group was significantly more likely to have antenatal steroid usage, have antenatal magnesium sulphate usage, were born to mothers with diabetes, hypertension and were delivered by C-section compared to the non-abortion group, which is consistent with some previous studies [ 8 , 10 – 12 , 33 ]. Ausbeck et al. analyzed 17670 maternal data of Birmingham Hospital from 2008 to 2017 and found that a history of 2 consecutive spontaneous abortions was associated with gestational diabetes in a subsequent pregnancy [ 8 ]. Weintraub et al. found that there was a significant association between a previous miscarriage and intrauterine growth restriction, hypertensive disorders, preeclampsia, cesarean delivery [ 33 ]. Bhattacharya et al. found the miscarriage group faced a higher risk of pre-eclampsia ( aOR 3.3, 99% CI 2.6–4.6) than women who had had a previous live birth [ 10 ]. On the other hand, Jivraj et al. found that there was no significant difference in the incidence of hypertension or diabetes between recurrent miscarriage group and the control group [ 9 ]. Neonatal Mortality and Major Morbidity Risks in the Abortion Group Although our study did not find an increased risk of mortality in the abortion group compared to the non-abortion group, we observed significantly higher incidences of a composite outcome: neonatal mortality or any major morbidity. Previous studies have shown that there was a significant association between a mother's history of miscarriage and perinatal mortality [ 14 , 33 ]. Field et al. conducted a retrospective cohort study involving 30053 women with a singleton pregnancy and found that recurrent miscarriage was associated with perinatal death (aOR 2.66, 95%CI 1.70–4.14)[ 14 ]. Similarly, Weintraub et al. carried out a large retrospective, population-based study, which indicated that perinatal mortality was significantly higher among women with an initial miscarriage (OR 1.57, 95% 1.24–1.98) [ 33 ]. The reason for the disparity could be attributed to differences in study populations. The research of Weintraub et al. was based on population-based data from the southern region of Israel spanning from 1988 to 2008, controlling for confounding factor such as maternal age. In contrast, our study focused on a multicenter cohort of VPIs in China, adjusting for important potential confounders including maternal age, gestational age, SGA, and so on. Additionally, the scope of study by Weintraub et al. did not explore the associations with other neonatal outcomes. To the best of our knowledge, this is the largest study investigating the association between neonatal outcomes and maternal abortion history, specifically focusing on first parity VPIs born to mothers with a prior abortion history. This can eliminate the potential impact of whether the previous pregnancy was successful on the next pregnancy. The possible reason of the elevated RDS, IVH and moderate or severe BPD risk in the abortion group In this study, the possible reason for the association between maternal either induced or spontaneous abortion and RDS, IVH, and moderate or severe BPD might be attributed to mothers with elective abortion experiencing higher levels of acute and chronic psychosocial stress. These stress factors can arise from conditions such as poverty, unsafe neighborhoods, and lack of social support, amongst others, which could activate the maternal or fetal hypothalamic-pituitary-adrenal (HPA) axis [ 34 , 35 ]. Additionally, the role of oxidative stress may also be associated with the increased occurrence of impaired lung development, including RDS and BPD [ 36 , 37 ]. When the rapid formation of oxygen reactive species surpasses the detoxification capacity of the antioxidative defense system, it can lead to a correlation with the occurrence of RDS and BPD[ 37 ]. Previous literature has reported that compared to the non-miscarriage group, the miscarriage group had a higher incidence of abnormal maternal uteroplacental blood vessels[ 38 , 39 ], as well as a higher occurrence of neonatal asphyxia [ 33 ]. Gunnarsdottir et al. found that a history of two or more miscarriages is associated with an increased risk of placental dysfunction disorders. They found that the proportion of placental abruption in women with two prior miscarriages was 0.81%, compared to 0.41% in those without prior miscarriages [ 39 ]. The possible reason for these findings is that both miscarriage and placental dysfunction disorders are associated with an imbalance in angiogenic activity, disturbances in uterine blood supply, and placental oxidative stress [ 40 – 43 ]. In our study, we observed that the proportions of newborns with Apgar score (1min) 0–3 in abortion group, one abortion group, and ≥2 abortions group were 7.1%, 6.7%, and 7.6%, respectively, which were significantly higher than the non-abortion group (5.6%). Similarly, the proportion of newborns with Apgar score (5min) 0–3 in the abortion group was also higher than the non-abortion group. We speculate that the higher risk of IVH in the abortion group compared to the non-abortion group could be attributed to a higher incidence of placental dysfunction disorders in the abortion group, leading to an increased occurrence of neonatal asphyxia. Subsequent hypoxia-ischemia may cause increased vascular wall permeability, resulting in blood extravasation and, consequently, a higher incidence of IVH [ 44 ]. Strengths and limitations The most remarkable aspect of our research lies in its extensive use of a large-scale dataset comprising perinatal information from multiple centers across China, specifically focusing on VPIs. This comprehensive analysis has allowed us to establish a compelling link between maternal abortion history and the incidence of mortality and morbidity rate of VPIs. The accuracy and completeness of the data are of utmost importance, and we maintained this high standard by rigorously adhering to a well-defined recruitment protocol. This study allows us to better ascertain the effect of maternal abortion history on neonatal outcomes in VPIs, and we can counsel and prognosticate for our patients with our nationwide data. Our study showed an important view that maternal abortion history, whether spontaneous or induced, may have a certain impact on the adverse outcomes of VPIs. Furthermore, the broader definition of abortions in China may also impact study outcomes. This encompasses a population broader than the one defined by the World Health Organization (WHO)[ 45 ], both in terms of gestational age and birth weight. This study included a larger group of pregnant women who may be at higher risk for placental insufficiency and other pregnancy complications. Our study has several limitations. Firstly, our study was conducted in a hospital-based setting, focusing on large tertiary NICUs in China known for their high-level neonatal care, which may not be representative of the general population. Secondly, we lack data on the gestational age of pregnancy loss, types of abortion, and underlying causes. At the same time, pregnant women with foetal death in the delivery room were not included in our study, so we may have underestimated the real mortality rate for each of these groups, which may have led to selection bias. This study has provided compelling evidence of a significant association between maternal abortion history and adverse outcomes in VPIs, including mortality or major morbidity, RDS, IVH, and moderate or severe BPD. For neonatal unit clinicians, our research offers crucial insights into VPIs with maternal abortion history. Based on the potential impact of maternal abortion history on newborns, it is necessary to provide additional information on related risks during antenatal counseling for these mothers. Furthermore, there should be increased attention to the care of these mothers during the antepartum period, as factors related to socioeconomic status differences are likely to be present. Conclusion Maternal abortion history is associated with increased risks of mortality or major morbidity, RDS, IVH, moderate or severe BPD in VPIs. Risk increased with the number of abortions. Our findings contribute to the significance of improved healthcare services and enhanced NICU provisions for VPIs, particularly for neonates with a maternal history of abortion. Further studies will explore the impact of different types of abortions, the time interval from the last abortion to the current pregnancy, and some social factors on neonatal outcomes. Abbreviations ART, assisted reproductive technology; BPD, bronchopulmonary dysplasia; CHNN, Chinese Neonatal Network; CI, confidence interval; cPVL, cystic periventricular leukomalacia; CXR, chest X-ray; GA, gestational age; HPA, hypothalamic-pituitary-adrenal; IQR, interquartile range; IVH, intraventricular haemorrhage; NEC, necrotizing enterocolitis; NICUs, neonatal intensive care units; OR, odds ratio; PDA, patent ductus arteriosus; RDS, respiratory distress syndrome; ROP, retinopathy of prematurity; SGA, small for gestational age; VPIs, very preterm infants; WHO, World Health Organization Declarations Ethics approval and consent to participate This study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). Ethical approval was obtained from the ethics review board of Children’s Hospital of Fudan University (2018–296), which was recognized by all participating hospitals. Waiver of informed consent were granted at all sites including 79 Chinese tertiary NICUs for de-identified data. Ethics committees that waived the consent included Ethics Committee of Children’s Hospital of Fudan University, Ethics Committee of Children's Hospital of Zhejiang University School of Medicine, Ethics Committee of The Third Affiliated Hospital of Zhengzhou University, Ethics Committee of Guangzhou Women and Children’s Medical Center, Ethics Committee of Tianjin Obstetrics & Gynecology Hospital, Ethics Committee of Gansu Provincial Maternity and Child Care Hospital, Ethics Committee of Northwest Women's and Children's Hospital, Ethics Committee of Shenzhen Maternity and Child Health Care Hospital, Ethics Committee of Guizhou Women and Children’s Hospital, Ethics Committee of Suzhou Municipal Hospital affiliated to Nanjing Medical University, Ethics Committee of Shengjing Hospital of China Medical University, Ethics Committee of Children’s Hospital of Shanxi, Ethics Committee of Quanzhou Women and Children’s Hospital, Ethics Committee of Fujian Women and Children’s Medical Center, Ethics Committee of Children’s Hospital of Nanjing Medical University, Ethics Committee of Hunan Children’s Hospital, Ethics Committee of Qingdao Women and Children’s Hospital, Ethics Committee of Nanjing Maternity and Child Health Care Hospital, Ethics Committee of The First Bethune Hospital of Jilin University, Ethics Committee of The First Affiliated Hospital of Anhui Medical University, Ethics Committee of Women and Children's Hospital of Guangxi Zhuang Autonomous Region, Ethics Committee of The First Affiliated Hospital of Xinjiang Medical University, Ethics Committee of Foshan Women and Children’s Hospital, Ethics Committee of The Affiliated Hospital of Qingdao University, Ethics Committee of Henan Children’s Hospital, Ethics Committee of Children’s Hospital of Shanghai, Ethics Committee of Chongqing Health Care Center for Women and Children, Ethics Committee of Children’s Hospital of Chongqing Medical University, Ethics Committee of Wuxi Maternity and Child Healthcare Hospital, Ethics Committee of Children's Hospital of Soochow University, Ethics Committee of People's Hospital of Xinjiang Uygur Autonomous Region, Ethics Committee of Yuying Children's Hospital Affiliated to Wenzhou Medical University, Ethics Committee of Shanghai First Maternity and Infant Hospital, Ethics Committee of Anhui Provincial Hospital, Ethics Committee of Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Ethics Committee of Qilu Children’s Hospital of Shandong University, Ethics Committee of The First Affiliated Hospital of Zhengzhou University, Ethics Committee of General Hospital of Ningxia Medical University, Ethics Committee of Hebei Children’s Hospital, Ethics Committee of Hainan Women and Children’s Hospital, Ethics Committee of The second XiangYA hospital of Central South University, Ethics Committee of Ningbo Women&Children Hospital, Ethics Committee of Xiamen Children’s Hospital, Ethics Committee of Shaanxi Provincial People’s Hospital, Ethics Committee of The Affiliated Hospital of Southwest Medical University, Ethics Committee of Shanghai Children’s Medical Center affiliated to Shanghai Jiaotong University School of Medicine, Ethics Committee of First Affiliated Hospital of Kunming Medical University, Ethics Committee of Changzhou Maternal and Children Health Care Hospital, Ethics Committee of Shenzhen Children’s Hospital, Ethics Committee of Jiangxi Provincial Children’s Hospital, Ethics Committee of Xiamen Maternity and Child Health Care Hospital, Ethics Committee of Zhuhai Center for Maternal and Child Health Care, Ethics Committee of Guangdong Women and Children's Hospital, Ethics Committee of Wuhan Chidren's Hospital, Ethics Committee of Beijing Children's Hospital of Capital Medical University, Ethics Committee of Maternal and Children Hospital of Shaoxing, Ethics Committee of The First People's Hospital of Yunnan Province, Ethics Committee of Dehong people's Hospital of Yunnan Province, Ethics Committee of First Affiliated Hospital of Xian Jiaotong University, Ethics Committee of Inner Mongolia maternal and child health care hospital, Ethics Committee of Dalian Municipal Women and Children’s Medical Center, Ethics Committee of Lianyungang Maternal and Children Health Hospital, Ethics Committee of Children's Hospital Affiliated to Capital Institute of Pediatrics, Ethics Committee of Anhui Children's Hoospital, Ethics Committee of Fuzhou Children’s Hospital of Fujian Province, Ethics Committee of Kunming Children's Hospital, Ethics Committee of Shenzhen Hospital of Hongkong University, Ethics Committee of Peking Union Medical College Hospital, Ethics Committee of Obstetrics & Gynecology Hospital of Fudan University, Ethics Committee of The Affiliated Hospital of Guizhou Medical University, Ethics Committee of Qinghai Women and Children Hospital, Ethics Committee of The International Peace Maternity & Child Health Hospital of China welfare institute, Ethics Committee of Children's Hospital of Zhejiang University, Ethics Committee of Inner Mongolia People's Hospital, Ethics Committee of Xiamen Humanity Hospital, Ethics Committee of Shanghai General Hospital, Ethics Committee of The First People's Hospital of Yinchuan, Ethics Committee of The Third Hospital of Nanchang, Ethics Committee of University of Alberta. Consent for publication Not applicable. Availability of data and materials The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding authors. Competing interests No financial or non-financial benefits have been received or will be received from any party related directly or indirectly to the subject of this article. Funding This work was funded by National Key Research and Development Program of China (2021YFC2701800, 2021YFC2701801), Shanghai Science and Technology Commission's Scientific and Technological Innovation Action Plan (No. 21Y21900800), and Canadian Institutes of Health Research (CTP87518). Authors’ contributions MY and LYH had full access to all the data in this study and take responsibility for the integrity of the data and the accuracy of the data analysis. YC, WHZ, SL, JMW, LYH were in charge of the concept and design. MY, JY, DNW, LYH assisted in the acquisition, analysis and interpretation of data. MY and LYH drafted of manuscripts. XBF and JLD were involved in administrative, technical or material support. All authors contributed to the final version. JY, DNW, YC, WHZ, SL, JMW, LYH supervised the study. A cknowledgement s We thank the data abstractors from the Chinese Neonatal Network. We thank all the staff at the Chinese Neonatal Network coordinating center for providing organizational support (Lin Yuan, PhD; Tongling Yang, RN; Hao Yuan, RN; Li Wang, RN; Yulan Lu, PhD). Group Information of the Chinese Neonatal Network Group Information of the Chinese Neonatal Network: Chairmen: Shoo K. Lee, MBBS, Mount Sinai Hospital, University of Toronto; Chao Chen, MD, Children’s Hospital of Fudan University. Vice-Chairmen: Lizhong Du, MD, Children's Hospital of Zhejiang University School of Medicine; Wenhao Zhou, Children’s Hospital of Fudan University. Site principle investigators of the Chinese Neonatal Network: Children's Hospital of Fudan University: Yun Cao, MD; The Third Affiliated Hospital of Zhengzhou University: Xiuyong Chen, MD; Guangzhou Women and Children’s Medical Center: Huyan Zhang, MD; Tianjin Obstetrics & Gynecology Hospital: Xiuying Tian, MD; Gansu Provincial Maternity and Child Care Hospital: Jingyun Shi, MD; Northwest Women's and Children's Hospital: Zhankui Li, MD; Shenzhen Maternity and Child Health Care Hospital: Chuanzhong Yang, MD; Guizhou Women and Children’s Hospital: Ling Liu, MD; Suzhou Municipal Hospital affiliated to Nanjing Medical University: Zuming Yang, MD; Shengjing Hospital of China Medical University: Jianhua Fu, MD; Children’s Hospital of Shanxi: Yong Ji, MD; Quanzhou Women and Children’s Hospital: Dongmei Chen, MD; Fujian Women and Children’s Medical Center: Changyi YANG, MD; Children’s Hospital of Nanjing Medical University: Rui Chen , MD; Hunan Children’s Hospital: Xiaoming Peng, MD; Qingdao Women and Children’s Hospital: Ruobing Shan, MD; Nanjing Maternity and Child Health Care Hospital: Shuping Han, MD; The First Bethune Hospital of Jilin University: Hui Wu, MD; The First Affiliated Hospital of Anhui Medical University: Lili WANG, MD; Women and Children's Hospital of Guangxi Zhuang Autonomous Region: Qiufen Wei, MD; The First Affiliated Hospital of Xinjiang Medical University: Mingxia Li, MD; Foshan Women and Children’s Hospital: Yiheng Dai, MD; The Affiliated Hospital of Qingdao University: Hong Jiang, MD; Henan Children’s Hospital: Wenqing Kang, MD; Children’s Hospital of Shanghai: Xiaohui Gong, MD; Chongqing Health Care Center for Women and Children: Xiaoyun Zhong, MD; Children’s Hospital of Chongqing Medical University: Yuan Shi, MD; Wuxi Maternity and Child Healthcare Hospital: Shanyu Jiang, MD; Children's Hospital of Soochow University: Bing Sun, MD; People's Hospital of Xinjiang Uygur Autonomous Region: Long Li, MD; Yuying Children's Hospital Affiliated to Wenzhou Medical University: Zhenlang Lin, MD; Shanghai First Maternity and Infant Hospital: Jiangqin Liu, MD; Anhui Provincial Hospital: Jiahua PAN, MD; Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine: Hongping Xia, MD; Qilu Children’s Hospital of Shandong University: Xiaoying Li, MD; The First Affiliated Hospital of Zhengzhou University: Falin Xu, MD; General Hospital of Ningxia Medical University: Yinping Qiu, MD; Hebei Children’s Hospital: Li Ma, MD; Hainan Women and Children’s Hospital: Ling Yang, MD; The second XiangYA hospital of Central South University:Xiaori He, MD; Ningbo Women&Children Hospital: Yanhong Li, MD; Xiamen Children’s Hospital: Deyi Zhuang, MD; Shaanxi Provincial People’s Hospital: Qin Zhang, MD; The Affiliated Hospital of Southwest Medical University: Wenbin Dong, MD; Shanghai Children’s Medical Center affiliated to Shanghai Jiaotong University School of Medicine: Jianhua Sun, MD; First Affiliated Hospital of Kunming Medical University: Kun Liang, MD; Changzhou Maternal and Children Health Care Hospital: Huaiyan Wang, MD; Shenzhen Children’s Hospital: Jinxing Feng, MD; Jiangxi Provincial Children’s Hospital: Liping Chen, MD; Xiamen Maternity and Child Health Care Hospital: Xinzhu Lin, MD; Zhuhai Center for Maternal and Child Health Care: Chunming Jiang, MD; Guangdong Women and Children's Hospital: Chuan Nie, MD; Wuhan Chidren's Hospital: Linkong Zeng, MD; Beijing Children's Hospital of Capital Medical University: Mingyan Hei, MD; Maternal and Children Hospital of Shaoxing: Hongdan Zhu, MD; The First People's Hospital of Yunnan Province: Hongying MI, MD; Dehong people's Hospital of Yunnan Province: Zhaoqing Yin, MD; First Affiliated Hospital of Xian Jiaotong University: Hongxia Song, MD; Inner Mongolia maternal and child health care hospital: Hongyun Wang, MD; Dalian Municipal Women and Children’s Medical Center: Dong Li, MD; Lianyungang Maternal and Children Health Hospital: Yan Gao , MD; Children's Hospital Affiliated to Capital Institute of Pediatrics: Yajuan Wang, MD; Anhui Children's Hoospital: Liying Dai, MD; Fuzhou Children’s Hospital of Fujian Province: Liyan ZHANG, MD; Kunming Children's Hospital: Yangfang Li, MD; Shenzhen Hospital of Hongkong University: Qianshen Zhang, MD; Peking Union Medical College Hospital: Guofang Ding, MD; Obstetrics & Gynecology Hospital of Fudan University : Jimei Wang, MD; The Affiliated Hospital of Guizhou Medical University: Xiaoxia Chen, MD; Qinghai Women and Children Hospital: Zhen Wang, MD; The International Peace Maternity & Child Health Hospital of China welfare institute: Zheng Tang, MD; Children's Hospital of Zhejiang University: Xiaolu Ma, MD; Inner Mongolia People's Hospital: Xiaomei Zhang, MD; Xiamen Humanity Hospital: Xiaolan Zhang, MD; Shanghai General Hospital: Fang Wu, MD; The First People's Hospital of Yinchuan: Yanxiang Chen, MD; The Third Hospital of Nanchang: Ying Wu, MD; Advisor: Joseph Ting, MBBS; University of Alberta. 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Ann Epidemiol. 2006;16(8):587–92. Cao Y, Jiang S, Sun J, Hei M, Wang L, Zhang H, et al. Assessment of Neonatal Intensive Care Unit Practices, Morbidity, and Mortality Among Very Preterm Infants in China. JAMA Netw Open. 2021;4(8):e2118904. Sun J, Cao Y, Hei M, Sun H, Wang L, Zhou W, et al. Front Pediatr. 2021;9:711200. Chinese Neonatal Network. Data Quality Improvement and Internal Data Audit of the Chinese Neonatal Network Data Collection System. Stoll BJ, Hansen N, Fanaroff AA, Wright LL, Carlo WA, Ehrenkranz RA, et al. Late-onset sepsis in very low birth weight neonates: the experience of the NICHD Neonatal Research Network. Pediatrics. 2002;110:285–91. International Committee for the Classification of Retinopathy of Prematurity. The International Classification of Retinopathy of Prematurity revisited. Arch Ophthalmol. 2005;123:991–9. Jobe AH, Bancalari E. Bronchopulmonary dysplasia. Am J Respir Crit Care Med. 2001;163:1723–9. Papile LA, Burstein J, Burstein R, Koffler H. Incidence and evolution of subependymal and hemorrhage: A study of infants with birth weights less than 1,500 gm. J Pediatr. 1978;92:529–34. Bell MJ, Ternberg JL, Feigin RD, Keating JP, Marshall R, Barton L, et al. Neonatal necrotizing enterocolitis. Therapeutic decisions based upon clinical staging. Ann Surg. 1978;187:1–7. Walsh MC, Kliegman RM. Necrotizing enterocolitis-treatment based on staging creteria. Pediatr Clin N Am. 1986;33:179–201. British Association of Perinatal Medicine. Guidelines for good practice in the management of neonatal respiratory distress syndrome. London: BAPM; 1999. Ballard JL, Novak KK, Driver M. A simplified score for assessment of fetal maturation of newly born infants. J Pediatr. 1979;95:769–74. Zhu L, Zhang R, Zhang S, Shi W, Yan W, Wang X, et al. Chinese neonatal birth weight curve for different gestational age. Chin J Pediatr. 2015;53:97–103. Intrapartum management of intraamniotic infection. ACOG Committee Opinion 712. American College of Obstetricians and Gynecologists. Obstet Gynecol. 2017;130(2):e95–101. Redline RW, Faye-Petersen O, Heller D, Qureshi F, Savell V, Vogler C, et al. Amniotic infection syndrome: nosology and reproducibility of placental reaction patterns. Pediatr Dev Pathol. 2003;6(5):435–48. International Association of Diabetes and Pregnancy Study Groups Consensus Panel, Metzger BE, Gabbe SG, Persson B, Buchanan TA, Catalano PA, et al. International association of diabetes and pregnancy study groups recommendations on the diagnosis and classification of hyperglycemia in pregnancy. Diabetes Care. 2010;33(3):676–82. Kattah AG, Garovic VD. The management of hypertension in pregnancy. Adv Chronic Kidney Dis. 2013;20(3):229–39. Weintraub AY, Sergienko R, Harlev A, Holcberg G, Mazor M, Wiznitzer A, et al. An initial miscarriage is associated with adverse pregnancy outcomes in the following pregnancy. Am J Obstet Gynecol. 2011;205(3):e2861–5. Moreau C, Kaminski M, Ancel PY, Bouyer J, Escande B, Thiriez G, et al. Previous induced abortions and the risk of very preterm delivery: results of the EPIPAGE study. BJOG. 2005;112(4):430–7. Rich-Edwards J, Krieger N, Majzoub J, Zierler S, Lieberman E, Gillman M. Maternal experiences of racism and violence as predictors of preterm birth: rationale and study design. Paediatr Perinat Epidemiol. 2001;15(Suppl 2):124–35. Marseglia L, D'Angelo G, Granese R, Falsaperla R, Reiter RJ, Corsello G, et al. Role of oxidative stress in neonatal respiratory distress syndrome. Free Radic Biol Med. 2019;142:132–7. Wang J, Dong W. Oxidative stress and bronchopulmonary dysplasia. Gene. 2018;678:177–83. Clark DA, Chaouat G, Arck PC, Mittruecker HW, Levy GA. Cytokine-dependent abortion in CBA x DBA/2 mice is mediated by the procoagulant fgl2 prothrombinase [correction of prothombinase]. J Immunol. 1998;160(2):545–9. Gunnarsdottir J, Stephansson O, Cnattingius S, Akerud H, Wikström AK. Risk of placental dysfunction disorders after prior miscarriages: a population-based study. Am J Obstet Gynecol. 2014;211(1):e341–8. Plaisier M. Decidualisation and angiogenesis. Best Pract Res Clin Obstet Gynaecol. 2011;25(3):259–71. Burton GJ, Jauniaux E. Placental oxidative stress: from miscarriage to preeclampsia. J Soc Gynecol Investig. 2004;11(6):342–52. Jauniaux E, Hempstock J, Greenwold N, Burton GJ. Trophoblastic oxidative stress in relation to temporal and regional differences in maternal placental blood flow in normal and abnormal early pregnancies. Am J Pathol. 2003;162(1):115–25. Ball E, Bulmer JN, Ayis S, Lyall F, Robson SC. Late sporadic miscarriage is associated with abnormalities in spiral artery transformation and trophoblast invasion. J Pathol. 2006;208(4):535–42. Zhao Y, Zhang W, Tian X. Analysis of risk factors of early intraventricular hemorrhage in very-low-birth-weight premature infants: a single center retrospective study. BMC Pregnancy Childbirth. 2022;22(1):890. Safe Abortion. Technical and Policy Guidance for Health Systems. 2nd ed. Geneva: World Health Organization; 2012. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 06 Oct, 2025 Read the published version in BMC Pregnancy and Childbirth → Version 1 posted Editorial decision: Revision requested 15 Aug, 2025 Reviewers agreed at journal 12 Aug, 2025 Reviews received at journal 12 Aug, 2025 Reviewers agreed at journal 10 Aug, 2025 Reviewers agreed at journal 07 Jun, 2025 Reviews received at journal 05 Jun, 2025 Reviewers agreed at journal 02 Jun, 2025 Reviewers invited by journal 24 Sep, 2024 Editor invited by journal 29 Aug, 2024 Editor assigned by journal 28 Aug, 2024 Submission checks completed at journal 28 Aug, 2024 First submitted to journal 19 Aug, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4941021","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":358246436,"identity":"092a1510-cf6a-41cd-b32b-5fb05d0aa7a3","order_by":0,"name":"Min Yang","email":"","orcid":"","institution":"Obstetrics and Gynecology Hospital of Fudan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Min","middleName":"","lastName":"Yang","suffix":""},{"id":358246437,"identity":"0f8988fa-40e6-4593-a777-73a91b1d41ec","order_by":1,"name":"Jie Yang","email":"","orcid":"","institution":"Children’s Hospital of Fudan University, National Children’s Medical Center","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Jie","middleName":"","lastName":"Yang","suffix":""},{"id":358246438,"identity":"374b514a-35ea-4024-b26a-eaba745df239","order_by":2,"name":"Dianna Wang","email":"","orcid":"","institution":"University of Alberta","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Dianna","middleName":"","lastName":"Wang","suffix":""},{"id":358246439,"identity":"66cbd616-1f86-4358-8bb6-ddffea6971d0","order_by":3,"name":"Jiale Dai","email":"","orcid":"","institution":"Obstetrics and Gynecology Hospital of Fudan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Jiale","middleName":"","lastName":"Dai","suffix":""},{"id":358246440,"identity":"4e16a737-da15-4040-8213-605eaef377e8","order_by":4,"name":"Xiaobo Fan","email":"","orcid":"","institution":"Obstetrics and Gynecology Hospital of Fudan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Xiaobo","middleName":"","lastName":"Fan","suffix":""},{"id":358246441,"identity":"41a09ad3-a2a5-4c9e-bd5c-3d8beb79238d","order_by":5,"name":"Yun Cao","email":"","orcid":"","institution":"Children’s Hospital of Fudan University, National Children’s Medical Center","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yun","middleName":"","lastName":"Cao","suffix":""},{"id":358246442,"identity":"7f17daf9-1cfc-4167-8222-1cb9637105f0","order_by":6,"name":"Wenhao Zhou","email":"","orcid":"","institution":"Children’s Hospital of Fudan University, National Children’s Medical Center","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Wenhao","middleName":"","lastName":"Zhou","suffix":""},{"id":358246443,"identity":"996fd3b0-75b4-40c1-8440-3d051912ad8f","order_by":7,"name":"Shoo K Lee","email":"","orcid":"","institution":"Mount Sinai 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Hu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3UlEQVRIiWNgGAWjYLACHiDmZ29sfJBQYUOCFsmew80GD86kkaDF4EZ6m+TDtkOEVZuz9xh+eFNz2N7gQGJbRQLbAQb+9u4EvFose84YS845djhx5oGDbTcSeO4wSJw5uwGvFoMbuRukedgOJ/AdbARqkXjGYCCRS1DL5t88/w7bMxxmbCtIMDhMlJZt0rxthxknHGNsY0hIIEbLmfPfLOf2pSfO7GFslkg4kMZD2C/H25JvvPlmbc8v//zhx5//bOT423vxa4GCZjiLhxjlIFBHrMJRMApGwSgYiQAAa9tTGg3CcDYAAAAASUVORK5CYII=","orcid":"","institution":"Children’s Hospital of Fudan University, National Children’s Medical Center","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Liyuan","middleName":"","lastName":"Hu","suffix":""}],"badges":[],"createdAt":"2024-08-19 23:36:33","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4941021/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4941021/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12884-025-08196-6","type":"published","date":"2025-10-06T15:57:26+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":66867653,"identity":"089e9e4f-4851-4007-9db8-ff61f66e5d47","added_by":"auto","created_at":"2024-10-17 09:22:17","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":300935,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFlow diagram of the study participants\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4941021/v1/0da1ce9d7f558070bb2407d8.jpeg"},{"id":93419693,"identity":"8275c5d8-88a3-4c24-82b4-eec26b495792","added_by":"auto","created_at":"2025-10-13 16:06:03","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1804079,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4941021/v1/37c8f917-1130-4902-99b0-de27c9afa73c.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Associations Between Maternal Abortion History and Neonatal Outcome among Very Preterm Infants：a multicenter cohort study","fulltext":[{"header":"Background","content":"\u003cp\u003eDespite improvements in maternal nutrition, prenatal care, and the treatment of maternal infections, global data from 166 countries shows that the global abortion rate was approximately 36\u0026ndash;44 per 1,000 women aged 15\u0026ndash;49 years between 1990 and 2019 [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. This includes both induced and spontaneous abortions, with spontaneous abortion being the most common complication of pregnancy, accounting for approximately 30% of all pregnancies.\u003c/p\u003e \u003cp\u003eThe rates of induced abortions vary across countries and regions. In China, the definition of abortion during pregnancy was established in 2020, stating that pregnancies terminated before 28 weeks\u0026rsquo; gestation and with fetuses weighing less than 1,000 grams are classified as abortions [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. China has a high number of induced abortions [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. In 2019, the documented number of induced abortions in China was 9.76\u0026nbsp;million [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], while the estimated actual number per year is around 13\u0026nbsp;million [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Considering the underreporting and concealment of induced abortions occurring in private hospitals and clinics in China, the actual number is likely to be higher. Over the past five years, the annual total of induced abortions in China has remained at approximately 9.5\u0026nbsp;million [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIt is well established that maternal previous history of abortions, particularly with one or multiple previous miscarriages, is associated with an increased risk of preterm birth [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. It is also associated with a higher risk of obstetric complications, such as need for cesarean section, gestational diabetes, preterm birth, stillbirth, low birth weight, neonatal admission, and mortality in subsequent pregnancies [\u003cspan additionalcitationids=\"CR9 CR10 CR11 CR12 CR13\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. It has been confirmed that induced abortion by vacuum aspiration is associated with an increased risk of first-trimester miscarriage in the subsequent pregnancies [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. This raises the question of whether these histories of spontaneous or induced abortions have adverse effects on very preterm infants. This potentially can have significant implications for public health.\u003c/p\u003e \u003cp\u003eUnfortunately, there have been limited studies assessing the association between previous maternal abortion history and neonatal outcomes, particularly for very preterm infants. Some studies have found an association between miscarriage history in primiparous women and adverse pregnancy outcomes including intrauterine fetal death and perinatal loss in subsequent pregnancies, although these studies had small sample sizes [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. There were also reports suggesting that induced abortion is not an independent risk factor for adverse obstetric outcome [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Our study aims to investigate whether maternal abortion history is associated with an increased risk of adverse neonatal outcome in subsequent pregnancies among VPIs in China.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design and Data Source\u003c/h2\u003e \u003cp\u003eThis retrospective cohort was based on the database of the Chinese Neonatal Network (CHNN) which prospectively collected data between January 1, 2019 and December 31, 2021. The CHNN was established in 2018 and is comprised of four national and four regional children's medical centers, as well as thirty provincial perinatal and children's medical centers across China. The number of participating hospitals in the CHNN has increased from 58 in 2019 to 70 in 2020 and 79 in 2021. All CHNN participating hospitals specialize in neonatal care and are recognized for their expertise in managing high-risk newborns. These hospitals were from national and regional children's hospitals, provincial perinatal and children's medical centers, as well as major referral centers in large cities representing approximately 5% of all VPIs in China [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eA standardized clinical database was implemented to monitor outcomes and care practices in the CHNN's neonatal intensive care units (NICUs). Trained abstractors utilized a standardized manual of variable definitions to collect data from NICU electronic medical records. During data entry into a customized database, an error-checking mechanism was implemented. Subsequently, the data were electronically submitted to the CHNN coordinating center at the Children's Hospital of Fudan University, ensuring patient anonymity. Investigators at each site were responsible for ensuring data accuracy and maintaining rigorous quality control procedures throughout the entire process [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eStudy Population\u003c/h2\u003e \u003cp\u003eThe study included all first parity singleton very preterm infants (VPIs) born at a gestational age of less than 32 weeks who were admitted to NICUs within 24 hours of birth and were part of the CHNN from 2019 to 2021. Infants with major congenital anomalies, those conceived through assisted reproductive technology (ART), transferred to other hospitals, without prenatal visits, with missing gravidity or parity information, and multiple pregnancies were excluded from the study.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eExposure\u003c/h2\u003e \u003cp\u003eAbortion is defined as the loss of a pregnancy before 28 weeks of gestation. The study population was divided into two groups based on whether the VPIs had a history of maternal abortion: the abortion group and the non-abortion group. The abortion group was further categorized into two subgroups: the 1-abortion group and the \u0026ge;\u0026thinsp;2 abortions group, based on the number of previous maternal abortions. Transfers and readmissions between participating hospitals were tracked as data for the same infants. VPIs who were stillborn, died in the delivery room, or were transferred to non-participating hospitals within 24 hours of birth were not included in the database.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eOutcomes and Definitions\u003c/h2\u003e \u003cp\u003eThe primary outcome was mortality or any major morbidity. Any major morbidity was defined as early-onset sepsis, late-onset sepsis, retinopathy of prematurity (ROP) stage3, 4 or 5, moderate or severe bronchopulmonary dysplasia (BPD), cystic periventricular leukomalacia (cPVL), intraventricular haemorrhage (IVH) grade 3 or 4 and necrotizing enterocolitis (NEC) stage 2 or 3. Early-onset sepsis was defined as a positive blood or cerebrospinal fluid culture and antibiotic therapy with onset\u0026thinsp;\u0026lt;\u0026thinsp;3 days [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Late-onset sepsis was defined as positive blood or cerebrospinal fluid culture with time of onset\u0026thinsp;\u0026gt;\u0026thinsp;3 days. ROP stage 3, 4 or 5 was defined according to the international classification of ROP [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. BPD was defined as a requirement for respiratory support at 36 weeks postmenstrual age or at discharge/transfer/death if before 36 weeks postmenstrual age [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. cPVL was defined as the presence of periventricular cysts on cranial ultrasound or MRI. IVH grade 3 or 4 was defined according to Papile\u0026rsquo;s criteria [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. NEC was defined according to Bell\u0026rsquo;s criteria [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. In-hospital mortality was defined the death of infants during hospitalisation. Early death was defined as death occurring less than 7 days after birth. PDA was diagnosed by cardiac ultrasound. RDS was defined according to a combination of clinical signs and symptoms, laboratory analysis and chest X-ray (CXR) [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eDefinitions of other covariates\u003c/h2\u003e \u003cp\u003eWe determined the gestational age (GA) by utilizing a hierarchical approach that involved the best obstetric estimate derived from antenatal ultrasound, menstrual history, obstetric examination, or a combination of these methods. In cases where the obstetric estimate was unavailable or differed from the postnatal estimate by more than two weeks, we estimated the gestational age using the Ballard score [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Small for gestational age (SGA) was defined as a birth weight below the 10th percentile for the corresponding gestational age, based on the Chinese neonatal birth weight values [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eChorioamnionitis encompassed both clinical chorioamnionitis and histopathological chorioamnionitis. Clinical chorioamnionitis was diagnosed by maternal fever alone (\u0026gt;\u0026thinsp;39.0\u0026deg;C), or with a temperature of 38.0-38.9\u0026deg;C that persists after 30 minutes and one additional clinical sign of infection such as maternal leukocytosis, purulent cervical discharge or fetal tachycardia [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Histopathological chorioamnionitis was defined as the presence of diffuse neutrophil infiltration into the chorioamniotic membranes [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Diabetes and hypertension diagnoses were based on corresponding disease criteria and measurements obtained during the follow-up period [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. Inborn referred to infants born in a maternity ward located at the same site as the NICU.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eEthics Approval\u003c/h2\u003e \u003cp\u003e This study received approval from the Ethics Committee of the Children's Hospital of Fudan University (identifier: 2018\u0026thinsp;\u0026minus;\u0026thinsp;296) and was acknowledged by all participating NICUs for the development, compilation, data transfer, hosting, and analysis of the CHNN dataset. Due to the retrospective nature of the analysis and the absence of direct intervention in the diagnosis and treatment of individual patients, individual consent for this study was waived in all 79 tertiary-level NICUs. The study was conducted in accordance with the principles outlined in the Declaration of Helsinki (revised 2013).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eMaternal and neonatal characteristics were compared between abortion and non-abortion groups. Frequencies (percentages) and medians (interquartile range [IQR]) were reported for categorical and continuous variables, respectively. Difference was assessed by Chi-square test for categorical variables and Wilcoxon rank test for continuous variables. Also subgroup comparison (1 abortion group vs. \u0026ge;2 abortions group) of abortion group was conducted.\u003c/p\u003e \u003cp\u003eNeonatal outcomes were compared between abortion and non-abortion groups. Frequencies (percentages) were reported and difference was assessed by Chi-square test. Furthermore, the abortion group was divided into 1 abortion group and \u0026ge;2 abortions group. Cochran-Armitage test was used to assess the trend of outcomes across non-abortion group, 1 abortion group and \u0026ge;2 abortions group.\u003c/p\u003e \u003cp\u003eUnivariate and multivariate logistic regressions were applied for neonatal outcomes. Odds ratios (95% confidence intervals) were estimated. All analysis was conducted by SAS 9.4 (SAS Institute, Cary, NC) with two-sided significance level 0.05.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eStudy Population\u003c/h2\u003e \u003cp\u003eDuring the study period, 12518 infants were first parity singleton VPIs admitted within 24hr after birth. Among them, 1730 infants were from multiple birth, 412 infants had no prenatal visit and 1 infant had no gravidity or parity information, 119 infants had major congenital anomalies, 467 infants were transferred to other hospital and 2533 infants conceived with assisted reproductive technology were excluded. As a result, 7256 first parity singleton VPIs were included in this study. Of these, 3133 (43.2%) infants had positive maternal abortion history (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe gestational age and birth weight of the abortion group were significantly lower than those of the non-abortion group. The median (P25, P75) gestational age of the abortion group and the non-abortion group were 29.9 (28.4, 31.0) and 30.0 (28.7, 31.0), respectively. The median (P25, P75) birth weight of abortion group and non-abortion group were 1280.0 (1050.0, 1500.0) and 1310.0 (1100.0, 1530.0), respectively. The abortion group was significantly more likely to have antenatal steroid usage (80.8% vs. 78.4%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), have antenatal magnesium sulphate therapy(58.3% vs. 54.3%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), were born to mothers with diabetes (20.0% vs. 16.3%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), were born to mothers with hypertension (26.7% vs. 22.0%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), were delivered by caesarean delivery (C-section) (58.4% vs. 50.6%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), and were inborn (80.7% vs. 78.4%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01) than non-abortion group. Significant differences were found among non-abortion, 1 abortion and \u0026ge;\u0026thinsp;2 abortions groups in maternal age, antenatal steroids, diabetes, hypertension, cesarean delivery, antenatal magnesium sulfate therapy, male, gestational age, birth weight, apgar score at 1 minute, and inborn (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDescriptive characteristics and outcomes in relation to the number of previous maternal abortions among VPIs\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCharacteristics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eAbortion group (N\u0026thinsp;=\u0026thinsp;3133)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003eNumber of previous abortions\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-abortion group (N\u0026thinsp;=\u0026thinsp;4123)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;1722)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026ge;2\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;1411)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4123/7256(56.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3133/7256(43.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1722/7256(23.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1411/7256(19.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMother\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMaternal age, years, median(P25, P75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28(26,31)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30(28,34)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30(27,32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e32(29,35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eantenatal steroids\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3124/3987(78.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2452/3035(80.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1318/1667(79.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1134/1368(82.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDiabetes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e667/4102(16.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e624/3116(20.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e318/1713(18.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e306/1403(21.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypertension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e904/4103(22.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e834/3123(26.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e456/1716(26.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e378/1407(26.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePROM\u0026thinsp;\u0026gt;\u0026thinsp;24h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1022/3994(25.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e716/3034(23.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e383/1670(22.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e333/1364(24.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCesarean delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2081/4115(50.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1827/3128(58.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e754/1718(43.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e547/1410(38.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChorioamnionitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e563/3241(17.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e426/2480(17.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e220/1351(16.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e206/1129(18.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.43\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAntenatal magnesium sulphate therapy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2065/3806(54.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1689/2895(58.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e884/1580(56.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e805/1315(61.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eInfant\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2345/4120(56.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1639/3126(52.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e913/1720(53.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e726/1406(51.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGestational age, weeks, median (P25, P75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30.0\u003c/p\u003e \u003cp\u003e(28.7,31.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e29.9\u003c/p\u003e \u003cp\u003e(28.4,31.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30.0\u003c/p\u003e \u003cp\u003e(28.6,31.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e29.7\u003c/p\u003e \u003cp\u003e(28.1,31.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBirth weight, grams, median (P25, P75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1310.0\u003c/p\u003e \u003cp\u003e(1100.0,1530.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1280.0\u003c/p\u003e \u003cp\u003e(1050.0,1500.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1290.0\u003c/p\u003e \u003cp\u003e(1065.0,1500.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1260.0\u003c/p\u003e \u003cp\u003e(1030.0,1500.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSmall for gestational age\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e331/4111(8.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e293/3112(9.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e162/1708(9.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e131/1404(9.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eApgar score (1-min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0\u0026ndash;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e229/4058(5.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e220/3095(7.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e113/1692(6.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e107/1403(7.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u0026ndash;6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e683/4058(16.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e593/3095(19.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e298/1692(17.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e295/1403(21.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u0026ndash;10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3146/4058(77.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2282/3095(73.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1281/1692(75.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1001/1403(71.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eApgar score (5-min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.09\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0\u0026ndash;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e46/3945(1.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e50/3035(1.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e26/1654(1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e24/1381(1.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u0026ndash;6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e197/3945(5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e176/3035(5.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e86/1654(5.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e90/1381(6.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u0026ndash;10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3702/3945(93.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2809/3035(92.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1542/1654(93.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1267/1381(91.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInborn\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3231/4123(78.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2528/3133(80.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1345/1722(78.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1183/1411(83.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003eAbbreviations: PROM, premature rupture of membranes.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003ea\u003c/sup\u003e\u003cem\u003eP\u003c/em\u003e values refer to comparisons between abortion group and non-abortion group.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003e\u003cem\u003eb\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eP\u003c/em\u003e values refer to comparisons across non-abortion group, 1 abortion group and \u0026ge;2 abortions group.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eThe trend of neonatal outcomes among the non-abortion group, 1 abortion group, and \u0026ge;\u0026thinsp;2 abortions group\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe abortion group was significantly more likely to have mortality or any major morbidity (44.7% vs. 40.8%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), RDS (55.4% vs. 48.2%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), PDA (50.1% vs. 47.4%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.02), NEC stage 2 or 3 (5.2% vs. 4.2%, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.04), IVH (38.7% vs. 35.7%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.01), IVH grade 3 or 4 (6.2% vs. 4.8%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.01), moderate or severe BPD (36.6% vs. 33.2%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), ROP (26.6% vs. 22.3%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), and ROP stage 3, 4, 5 (3.5% vs. 2.5%, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.03) than non-abortion group.\u003c/p\u003e \u003cp\u003eWe categorized the abortion group into two subgroups: 1 abortion and \u0026ge;\u0026thinsp;2 abortions group. The incidence of mortality or any major morbidity (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), respiratory distress syndrome (RDS) (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), patent ductus arteriosus (PDA) (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.01), intraventricular haemorrhage (IVH) (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), IVH stage 3 or 4 (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.04), moderate or severe bronchopulmonary dysplasia (BPD) (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), retinopathy of prematurity (ROP) (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), ROP stage 3, 4, or 5 (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.03) tended to increase significantly with increasing number of maternal abortion histories across non-abortion group, 1 abortion and \u0026ge;2 abortions group (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCrude percentage of neonatal outcome according to the number of previous maternal abortions among VPIs\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003eNumber of previous abortions\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP-\u003c/em\u003etrend\u003csup\u003ee\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOutcome, n/N (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-abortion group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAbortion group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026ge;2\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMortality or any major morbidity\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1681/4123(40.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1400/3133(44.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e739/1722(42.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e661/1411(46.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMortality\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e477/4123(11.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e371/3133(11.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e192/1722(11.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e179/1411(12.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.38\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIn-hospital mortality\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e139/3595(3.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e121/2737(4.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e61/1509(4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e60/1228(4.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.14\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEarly death\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e81/3923(2.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e69/2966(2.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e35/1617(2.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e34/1349(2.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.35\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRDS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1989/4123(48.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1734/3133(55.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e911/1722(52.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e823/1411(58.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePDA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1893/3997(47.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1522/3040(50.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e819/1665(49.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e703/1375(51.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNEC stage 2 or 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e173/4123(4.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e163/3133(5.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e92/1722(5.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e71/1411(5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVH\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1329/3725(35.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1101/2843(38.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e593/1560(38.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e508/1283(39.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVH grade 3 or 4\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e199/4123(4.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e194/3133(6.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e110/1722(6.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e84/1411(6.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ecPVL\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e168/3710(4.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e134/2829(4.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e70/1555(4.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e64/1274(5.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.53\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEarly-onset sepsis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e48/4123(1.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e41/3133(1.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20/1722(1.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e21/1411(1.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.40\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLate-onset sepsis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e308/4123(7.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e239/3133(7.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e129/1722(7.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e110/1411(7.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.72\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eModerate or severe BPD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1370/4123(33.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1145/3133(36.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e599/1722(34.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e546/1411(38.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eROP\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e723/3249(22.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e654/2462(26.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e363/1361(26.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e291/1101(26.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eROP stage 3, 4, or 5\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e80/3249(2.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e85/2460(3.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e46/1361(3.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e39/1101(3.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003eAbbreviations: NEC, necrotizing enterocolitis; BPD, bronchopulmonary dysplasia; IVH, intraventricular hemorrhage; PVL, periventricular leucomalacia; ROP, retinopathy of prematurity; RDS, respiratory distress syndrome; PDA, patent ductus arteriosus.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003ea\u003c/sup\u003eAny major morbidity included early-onset sepsis, late-onset sepsis, ROP stage3, 4 or 5, moderate or severe BPD, cPVL, IVH grade 3 or 4 and NEC stage 2 or 3.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003eb\u003c/sup\u003eIncidence of IVH grade 3 or 4 and cPVL were calculated within Infants who had neuroimaging results.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003ec\u003c/sup\u003e Incidence of ROP and ROP stage 3, 4 or 5 were calculated among infants with eye examinations in the NICU.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003ed\u003c/sup\u003e\u003cem\u003eP\u003c/em\u003e values refer to comparisons between abortion group and non-abortion group.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003ee\u003c/sup\u003eTest for trend based on variable across non-abortion group, 1 abortion group and \u0026ge;2 abortions group.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eImpact of maternal abortion history on neonatal outcomes\u003c/h2\u003e \u003cp\u003eAfter adjusting for potential confounders, overall the abortion group had higher odds of mortality or any major morbidity (adjusted odds ratio [OR] 1.15, 95% confidence interval [CI] 1.03\u0026ndash;1.29), RDS (aOR 1.22, 95% CI 1.08\u0026ndash;1.38), IVH (aOR 1.17, 95% CI 1.05\u0026ndash;1.31), IVH grade 3 or 4 (aOR 1.27, 95% CI 1.01\u0026ndash;1.59), compared to the non-abortion group.\u003c/p\u003e \u003cp\u003eThe impact of maternal abortion history on neonatal outcomes is more significant for mothers with two or more abortions compared to mothers with one abortion. VPIs of mothers with two or more abortions had the higher risk of mortality or any major morbidity (aOR 1.18, 95% CI 1.02\u0026ndash;1.36), RDS (aOR 1.35, 95% CI 1.18\u0026ndash;1.56), IVH (aOR 1.23, 95% CI 1.07\u0026ndash;1.43) and moderate or severe BPD (aOR 1.17, 95% CI 1.01\u0026ndash;1.36), compared to the non-abortion group. While VPIs of mothers with one abortion had the highest risk of RDS (aOR 1.15, 95% CI 1.01\u0026ndash;1.30), IVH grade 3 or 4 (aOR 1.38, 95% CI 1.07\u0026ndash;1.80) compared to the non-abortion group (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e\u003cstrong\u003eTable 3. Odds ratios for the association between previous abortion history and the risk of neonatal outcome among VPIs according to the number of previous abortions\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"775\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 132px;\"\u003e\n \u003cp\u003eOutcome\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 208px;\"\u003e\n \u003cp\u003eUnadjusted OR(95% CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 208px;\"\u003e\n \u003cp\u003eAdjusted OR(95%CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 113px;\"\u003e\n \u003cp\u003eAbortion group\u003csup\u003e\u0026nbsp;b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 208px;\"\u003e\n \u003cp\u003eNumber of previous abortions\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 113px;\"\u003e\n \u003cp\u003eAbortion group\u003csup\u003eb,c\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 208px;\"\u003e\n \u003cp\u003eNumber of previous abortions\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026sup3;2\u003csup\u003e\u0026nbsp;b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1\u003csup\u003eb,c\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u0026sup3;2\u003csup\u003eb,c\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003eMortality or any major morbidity\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.20(1.09,1.32)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.12(1.00,1.26)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.28(1.13,1.44)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.15(1.03,1.29)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.08(0.95,1.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.18(1.02,1.36)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003eMortality\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.02(0.89,1.18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.96(0.80,1.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.11(0.92,1.33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e0.93(0.78,1.10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.84(0.67,1.03)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.00(0.80,1.24)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003eIn-hospital mortality\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.15(0.90,1.49)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.05(0.77,1.42)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.28(0.94,1.74)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e0.93(0.70,1.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.88(0.62,1.26)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.92(0.63,1.33)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003eEarly death\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.15(0.83,1.61)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.05(0.70,1.57)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.23(0.82,1.84)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.00(0.69,1.46)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.98(0.62,1.53)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.87(0.55,1.40)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003eRDS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.33(1.22,1.47)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.21(1.08,1.35)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.50(1.33,1.70)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.22(1.08,1.38)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.15(1.01,1.30)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.35(1.18,1.56)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003ePDA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.12(1.02,1.23)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.08(0.96,1.21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.16(1.03,1.32)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.00(0.90,1.11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.98(0.86,1.11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.07(0.94,1.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003eNEC stage\u0026nbsp;2 or 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.26(1.01,1.56)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.29(0.99,1.67)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.21(0.91,1.61)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.24(0.97,1.58)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.30(0.98,1.72)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.16(0.85,1.59)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003eIVH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.14(1.03,1.26)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.11(0.98,1.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.18(1.04,1.35)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.17(1.05,1.31)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.13(0.99,1.29)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.23(1.07,1.43)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eIVH grade 3 or 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.30(1.06,1.59)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.35(1.06,1.71)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1.25(0.96,1.62)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.27(1.01,1.59)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.38(1.07,1.80)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1.14(0.85,1.53)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003ecPVL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.04(0.83,1.32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.99(0.75,1.32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.12(0.83,1.50)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.01(0.78,1.30)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.94(0.69,1.28)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.14(0.82,1.57)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003eEarly-onset sepsis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.13(0.74,1.71)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.10(0.59,1.69)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.28(0.77,2.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.00(0.63,1.58)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.97(0.55,1.68)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.99(0.55,1.77)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003eLate-onset sepsis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.02(0.86,1.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.00(0.81,1.24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.05(0.84,1.31)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e0.96(0.79,1.17)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.93(0.74,1.18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0.94(0.74,1.21)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003eModerate or severe BPD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.15(1.05,1.27)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.07(0.95,1.21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.27(1.12,1.44)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.09(0.97,1.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.00(0.87,1.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.17(1.01,1.36)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eROP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.26(1.12,1.42)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.27(1.10,1.47)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.26(1.07,1.47)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003e1.06(0.92,1.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1.10(0.93,1.30)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1.00(0.83,1.21)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003eROP stage 3, 4, or 5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.42(1.04,1.93)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.39(0.96,2.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.46(0.99,2.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e1.10(0.77,1.56)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.17(0.78,1.76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1.01(0.65,1.58)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations: NEC, necrotizing enterocolitis; BPD, bronchopulmonary dysplasia; IVH, intraventricular hemorrhage; PVL, periventricular leucomalacia; ROP, retinopathy of prematurity; RDS, respiratory distress syndrome; PDA, patent ductus arteriosus, OR,\u0026nbsp;odds ratios;\u0026nbsp;CI, confidence interval.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e Any major morbidity included early-onset sepsis, late-onset sepsis, ROP stage3, 4 or 5, moderate or severe BPD, cPVL, IVH stage 3 or 4 and NEC stage 2 or 3.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003eb\u003c/sup\u003e Non-abortion group was the reference group.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003ec\u003c/sup\u003e Adjusted for maternal age, antenatal steroid usage, hypertension, diabetics, gestational age, small for gestational age, antenatal magnesium sulphate therapy, sex, delivery mode, inborn.\u003c/p\u003e \u003cp\u003eWe treated maternal abortion history as a continuous variable and analyzed its association with neonatal outcomes. The results showed VPIs of mothers with abortion history had higher risk of mortality or any major morbidity (aOR 1.07, 95% CI 1.02\u0026ndash;1.13), RDS (aOR 1.14, 95% CI 1.09\u0026ndash;1.20), IVH (aOR 1.07, 95% CI 1.02\u0026ndash;1.13) and moderate or severe BPD (aOR 1.05, 95% CI 1.00-1.11), compared to the non-abortion group (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCrude OR and adjusted OR with each additional number of abortion of neonatal outcome\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOutcome\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eUnadjusted OR(95% CI) \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAdjusted OR(95%CI) \u003csup\u003ea,b\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMortality or any major morbidity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e1.08(1.03,1.12)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e1.07(1.02,1.13)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMortality\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.02(0.95\u0026ndash;1.08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.99(0.91,1.07)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIn-hospital mortality\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.06(0.96\u0026ndash;1.18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.97(0.86\u0026ndash;1.11)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEarly death\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1,05(0.91\u0026ndash;1.20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.96(0.82,1.13)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRDS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e1.16(1.11\u0026ndash;1.21)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e1.14(1.09,1.20)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePDA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e1.05(1.01\u0026ndash;1.10)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.01(0.96,1.06)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNEC stage 2 or 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.07(0.97\u0026ndash;1.17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.06(0.95,1.17)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e1.05(1.01\u0026ndash;1.10)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e1.07(1.02,1.13)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIVH grade 3 or 4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.04(0.95\u0026ndash;1.13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.01(0.91,1.12)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ecPVL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.00(0.90\u0026ndash;1.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.98(0.87,1.11)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEarly-onset sepsis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.12(0.95\u0026ndash;1.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.03(0.85,1.26)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLate-onset sepsis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.00(0.93\u0026ndash;1.09)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.99(0.90,1.08)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eModerate or severe BPD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e1.07(1.02\u0026ndash;1.11)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e1.05(1.00,1.11)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eROP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e1.08(1.02\u0026ndash;1.14)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.99(0.93,1.06)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eROP stage 3, 4, or 5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e1.17(1.04\u0026ndash;1.32)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.05(0.91,1.21)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003eAbbreviations: NEC, necrotizing enterocolitis; BPD, bronchopulmonary dysplasia; IVH, intraventricular hemorrhage; PVL, periventricular leucomalacia; ROP, retinopathy of prematurity; RDS, respiratory distress syndrome; PDA, patent ductus arteriosus, OR, odds ratios; CI, confidence interval.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e\u003csup\u003ea\u003c/sup\u003e Non-abortion group was the reference group.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e\u003csup\u003eb\u003c/sup\u003e Number of previous abortions was treated as a continuous variable, and adjusted for maternal age, antenatal steroid usage, hypertension, diabetics, gestational age, small for gestational age, antenatal magnesium sulphate therapy, sex, delivery mode, inborn.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003ePrincipal findings\u003c/h2\u003e \u003cp\u003eThis national-level study analyzed 12518 very preterm infants (VPIs) admitted to 57 Chinese tertiary NICUs from January 2019 to December 2021. It aimed to address the knowledge gap in neonatal perinatal characteristics and outcomes between abortion and non-abortion groups in VPIs. The major finding of our study was that the abortion group had more adverse neonatal outcomes. Whereas some previous studies have focused on the obstetrics outcomes and the risk of further miscarriage in women with previous abortions [\u003cspan additionalcitationids=\"CR9 CR10 CR11\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Interestingly, in the univariate analysis, we found a significant association between maternal abortion history and several adverse neonatal outcomes. However, after adjusting for confounding factors such as maternal age, antenatal steroid usage, hypertension, diabetes, gestational age, small for gestational age, antenatal magnesium sulfate therapy, sex, delivery mode, and inborn status, many of these associations disappeared. Comparing the abortion group to the non-abortion group, as well as to the groups with one or more than two abortions, we observed a significantly increased risk of mortality or any major morbidity, RDS, IVH, and moderate or severe BPD among neonates with maternal abortion history in VPIs.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eMaternal characteristics\u003c/h2\u003e \u003cp\u003eOur finding revealed that abortion group was significantly more likely to have antenatal steroid usage, have antenatal magnesium sulphate usage, were born to mothers with diabetes, hypertension and were delivered by C-section compared to the non-abortion group, which is consistent with some previous studies [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Ausbeck et al. analyzed 17670 maternal data of Birmingham Hospital from 2008 to 2017 and found that a history of 2 consecutive spontaneous abortions was associated with gestational diabetes in a subsequent pregnancy [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Weintraub et al. found that there was a significant association between a previous miscarriage and intrauterine growth restriction, hypertensive disorders, preeclampsia, cesarean delivery [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Bhattacharya et al. found the miscarriage group faced a higher risk of pre-eclampsia ( aOR 3.3, 99% CI 2.6\u0026ndash;4.6) than women who had had a previous live birth [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. On the other hand, Jivraj et al. found that there was no significant difference in the incidence of hypertension or diabetes between recurrent miscarriage group and the control group [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eNeonatal Mortality and Major Morbidity Risks in the Abortion Group\u003c/h2\u003e \u003cp\u003eAlthough our study did not find an increased risk of mortality in the abortion group compared to the non-abortion group, we observed significantly higher incidences of a composite outcome: neonatal mortality or any major morbidity. Previous studies have shown that there was a significant association between a mother's history of miscarriage and perinatal mortality [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Field et al. conducted a retrospective cohort study involving 30053 women with a singleton pregnancy and found that recurrent miscarriage was associated with perinatal death (aOR 2.66, 95%CI 1.70\u0026ndash;4.14)[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Similarly, Weintraub et al. carried out a large retrospective, population-based study, which indicated that perinatal mortality was significantly higher among women with an initial miscarriage (OR 1.57, 95% 1.24\u0026ndash;1.98) [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. The reason for the disparity could be attributed to differences in study populations. The research of Weintraub et al. was based on population-based data from the southern region of Israel spanning from 1988 to 2008, controlling for confounding factor such as maternal age. In contrast, our study focused on a multicenter cohort of VPIs in China, adjusting for important potential confounders including maternal age, gestational age, SGA, and so on. Additionally, the scope of study by Weintraub et al. did not explore the associations with other neonatal outcomes. To the best of our knowledge, this is the largest study investigating the association between neonatal outcomes and maternal abortion history, specifically focusing on first parity VPIs born to mothers with a prior abortion history. This can eliminate the potential impact of whether the previous pregnancy was successful on the next pregnancy.\u003c/p\u003e \u003cp\u003e \u003cb\u003eThe possible reason of the elevated RDS, IVH and moderate or severe BPD risk in the abortion group\u003c/b\u003e \u003c/p\u003e \u003cp\u003eIn this study, the possible reason for the association between maternal either induced or spontaneous abortion and RDS, IVH, and moderate or severe BPD might be attributed to mothers with elective abortion experiencing higher levels of acute and chronic psychosocial stress. These stress factors can arise from conditions such as poverty, unsafe neighborhoods, and lack of social support, amongst others, which could activate the maternal or fetal hypothalamic-pituitary-adrenal (HPA) axis [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. Additionally, the role of oxidative stress may also be associated with the increased occurrence of impaired lung development, including RDS and BPD [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. When the rapid formation of oxygen reactive species surpasses the detoxification capacity of the antioxidative defense system, it can lead to a correlation with the occurrence of RDS and BPD[\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePrevious literature has reported that compared to the non-miscarriage group, the miscarriage group had a higher incidence of abnormal maternal uteroplacental blood vessels[\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e], as well as a higher occurrence of neonatal asphyxia [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Gunnarsdottir et al. found that a history of two or more miscarriages is associated with an increased risk of placental dysfunction disorders. They found that the proportion of placental abruption in women with two prior miscarriages was 0.81%, compared to 0.41% in those without prior miscarriages [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. The possible reason for these findings is that both miscarriage and placental dysfunction disorders are associated with an imbalance in angiogenic activity, disturbances in uterine blood supply, and placental oxidative stress [\u003cspan additionalcitationids=\"CR41 CR42\" citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e]. In our study, we observed that the proportions of newborns with Apgar score (1min) 0\u0026ndash;3 in abortion group, one abortion group, and \u0026ge;2 abortions group were 7.1%, 6.7%, and 7.6%, respectively, which were significantly higher than the non-abortion group (5.6%). Similarly, the proportion of newborns with Apgar score (5min) 0\u0026ndash;3 in the abortion group was also higher than the non-abortion group. We speculate that the higher risk of IVH in the abortion group compared to the non-abortion group could be attributed to a higher incidence of placental dysfunction disorders in the abortion group, leading to an increased occurrence of neonatal asphyxia. Subsequent hypoxia-ischemia may cause increased vascular wall permeability, resulting in blood extravasation and, consequently, a higher incidence of IVH [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003eStrengths and limitations\u003c/h2\u003e \u003cp\u003eThe most remarkable aspect of our research lies in its extensive use of a large-scale dataset comprising perinatal information from multiple centers across China, specifically focusing on VPIs. This comprehensive analysis has allowed us to establish a compelling link between maternal abortion history and the incidence of mortality and morbidity rate of VPIs. The accuracy and completeness of the data are of utmost importance, and we maintained this high standard by rigorously adhering to a well-defined recruitment protocol. This study allows us to better ascertain the effect of maternal abortion history on neonatal outcomes in VPIs, and we can counsel and prognosticate for our patients with our nationwide data. Our study showed an important view that maternal abortion history, whether spontaneous or induced, may have a certain impact on the adverse outcomes of VPIs. Furthermore, the broader definition of abortions in China may also impact study outcomes. This encompasses a population broader than the one defined by the World Health Organization (WHO)[\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e], both in terms of gestational age and birth weight. This study included a larger group of pregnant women who may be at higher risk for placental insufficiency and other pregnancy complications.\u003c/p\u003e \u003cp\u003eOur study has several limitations. Firstly, our study was conducted in a hospital-based setting, focusing on large tertiary NICUs in China known for their high-level neonatal care, which may not be representative of the general population. Secondly, we lack data on the gestational age of pregnancy loss, types of abortion, and underlying causes. At the same time, pregnant women with foetal death in the delivery room were not included in our study, so we may have underestimated the real mortality rate for each of these groups, which may have led to selection bias.\u003c/p\u003e \u003cp\u003eThis study has provided compelling evidence of a significant association between maternal abortion history and adverse outcomes in VPIs, including mortality or major morbidity, RDS, IVH, and moderate or severe BPD. For neonatal unit clinicians, our research offers crucial insights into VPIs with maternal abortion history. Based on the potential impact of maternal abortion history on newborns, it is necessary to provide additional information on related risks during antenatal counseling for these mothers. Furthermore, there should be increased attention to the care of these mothers during the antepartum period, as factors related to socioeconomic status differences are likely to be present.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eMaternal abortion history is associated with increased risks of mortality or major morbidity, RDS, IVH, moderate or severe BPD in VPIs. Risk increased with the number of abortions. Our findings contribute to the significance of improved healthcare services and enhanced NICU provisions for VPIs, particularly for neonates with a maternal history of abortion. Further studies will explore the impact of different types of abortions, the time interval from the last abortion to the current pregnancy, and some social factors on neonatal outcomes.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eART, assisted reproductive technology; BPD, bronchopulmonary dysplasia; CHNN, Chinese Neonatal Network; CI, confidence interval; cPVL, cystic periventricular leukomalacia; CXR, chest X-ray; GA, gestational age; HPA, hypothalamic-pituitary-adrenal; IQR, interquartile range; IVH, intraventricular haemorrhage; NEC, \u0026nbsp; necrotizing enterocolitis; NICUs, neonatal intensive care units; OR, odds ratio; PDA, patent ductus arteriosus; RDS, respiratory distress syndrome; ROP, retinopathy of prematurity; SGA, small for gestational age; VPIs, very preterm infants; WHO, World Health Organization\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). Ethical approval was obtained from the ethics review board of Children’s Hospital of Fudan University (2018–296), which was recognized by all participating hospitals. Waiver of informed consent were granted at all sites including 79 Chinese tertiary NICUs for de-identified data. Ethics committees that waived the consent included Ethics Committee of Children’s Hospital of Fudan University, Ethics Committee of\u0026nbsp;Children's Hospital of Zhejiang University School of Medicine,\u0026nbsp;Ethics Committee of\u0026nbsp;The Third Affiliated Hospital of Zhengzhou University,\u0026nbsp;Ethics Committee of\u0026nbsp;Guangzhou Women and Children’s Medical Center,\u0026nbsp;Ethics Committee of\u0026nbsp;Tianjin Obstetrics \u0026amp; Gynecology Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Gansu Provincial Maternity and Child Care Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Northwest Women's and Children's Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Shenzhen Maternity and Child Health Care Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Guizhou Women and Children’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Suzhou Municipal Hospital affiliated to Nanjing Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp;Shengjing Hospital of China Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp;Children’s Hospital of Shanxi,\u0026nbsp;Ethics Committee of\u0026nbsp;Quanzhou Women and Children’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Fujian Women and Children’s Medical Center,\u0026nbsp;Ethics Committee of\u0026nbsp;Children’s Hospital of Nanjing Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp;Hunan Children’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Qingdao Women and Children’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Nanjing Maternity and Child Health Care Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;The First Bethune Hospital of Jilin University,\u0026nbsp;Ethics Committee of\u0026nbsp;The First Affiliated Hospital of Anhui Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp; Women and Children's Hospital of Guangxi Zhuang Autonomous Region,\u0026nbsp;Ethics Committee of\u0026nbsp;The First Affiliated Hospital of Xinjiang Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp;Foshan Women and Children’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;The Affiliated Hospital of Qingdao University,\u0026nbsp;Ethics Committee of\u0026nbsp;Henan Children’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Children’s Hospital of Shanghai,\u0026nbsp;Ethics Committee of\u0026nbsp;Chongqing Health Care Center for Women and Children, \u0026nbsp;Ethics Committee of\u0026nbsp;Children’s Hospital of Chongqing Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp;Wuxi Maternity and Child Healthcare Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Children's Hospital of Soochow University,\u0026nbsp;Ethics Committee of\u0026nbsp;People's Hospital of Xinjiang Uygur Autonomous Region,\u0026nbsp;Ethics Committee of\u0026nbsp;Yuying Children's Hospital Affiliated to Wenzhou Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp;Shanghai First Maternity and Infant Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Anhui Provincial Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine,\u0026nbsp;Ethics Committee of\u0026nbsp;Qilu Children’s Hospital of Shandong University,\u0026nbsp;Ethics Committee of\u0026nbsp;The First Affiliated Hospital of Zhengzhou University,\u0026nbsp;Ethics Committee of\u0026nbsp;General Hospital of Ningxia Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp;Hebei Children’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Hainan Women and Children’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;The second XiangYA hospital of Central South University,\u0026nbsp;Ethics Committee of\u0026nbsp;Ningbo Women\u0026amp;Children Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Xiamen Children’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Shaanxi Provincial People’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;The Affiliated Hospital of Southwest Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp;Shanghai Children’s Medical Center affiliated to Shanghai Jiaotong University School of Medicine,\u0026nbsp;Ethics Committee of\u0026nbsp;First Affiliated Hospital of Kunming Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp;Changzhou Maternal and Children Health Care Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Shenzhen Children’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Jiangxi Provincial Children’s Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Xiamen Maternity and Child Health Care Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Zhuhai Center for Maternal and Child Health Care,\u0026nbsp;Ethics Committee of\u0026nbsp;Guangdong Women and Children's Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Wuhan Chidren's Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Beijing Children's Hospital of Capital Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp;Maternal and Children Hospital of Shaoxing,\u0026nbsp;Ethics Committee of\u0026nbsp;The First People's Hospital of Yunnan Province,\u0026nbsp;Ethics Committee of\u0026nbsp;Dehong people's Hospital of Yunnan Province,\u0026nbsp;Ethics Committee of\u0026nbsp;First Affiliated Hospital of Xian Jiaotong University,\u0026nbsp;Ethics Committee of\u0026nbsp;Inner Mongolia maternal and child health care hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Dalian Municipal Women and Children’s Medical Center,\u0026nbsp;Ethics Committee of\u0026nbsp;Lianyungang Maternal and Children Health Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Children's Hospital Affiliated to Capital Institute of Pediatrics,\u0026nbsp;Ethics Committee of\u0026nbsp;Anhui Children's Hoospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Fuzhou Children’s Hospital of Fujian Province,\u0026nbsp;Ethics Committee of\u0026nbsp;Kunming Children's Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Shenzhen Hospital of Hongkong University,\u0026nbsp;Ethics Committee of\u0026nbsp;Peking Union Medical College Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Obstetrics \u0026amp; Gynecology Hospital of Fudan University,\u0026nbsp;Ethics Committee of\u0026nbsp;The Affiliated Hospital of Guizhou Medical University,\u0026nbsp;Ethics Committee of\u0026nbsp;Qinghai Women and Children Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;The International Peace Maternity \u0026amp; Child Health Hospital of China welfare institute,\u0026nbsp;Ethics Committee of\u0026nbsp;Children's Hospital of Zhejiang University, \u0026nbsp;Ethics Committee of\u0026nbsp;Inner Mongolia People's Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Xiamen Humanity Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;Shanghai General Hospital,\u0026nbsp;Ethics Committee of\u0026nbsp;The First People's Hospital of Yinchuan,\u0026nbsp;Ethics Committee of\u0026nbsp;The Third Hospital of Nanchang,\u0026nbsp;Ethics Committee of\u0026nbsp;University of Alberta.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo financial or non-financial benefits have been received or will be received from any party related directly or indirectly to the subject of this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was funded by National Key Research and Development Program of China (2021YFC2701800, 2021YFC2701801), Shanghai Science and Technology Commission's Scientific and Technological Innovation Action Plan (No. 21Y21900800), and Canadian Institutes of Health Research (CTP87518).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors’ contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMY and LYH had full access to all the data in this study and take responsibility for the integrity of the data and the accuracy of the data analysis. YC,\u0026nbsp;WHZ, SL,\u0026nbsp;JMW, LYH were in charge of the concept and design. MY,\u0026nbsp;JY, DNW,\u0026nbsp;LYH assisted in the acquisition, analysis and interpretation of data. MY and LYH drafted of manuscripts. XBF and JLD were involved in administrative, technical or material support. All authors contributed to the final version.\u0026nbsp;JY,\u0026nbsp;DNW,\u0026nbsp;YC,\u0026nbsp;WHZ, SL,\u0026nbsp;JMW, LYH supervised the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eA\u003c/strong\u003e\u003cstrong\u003ecknowledgement\u003c/strong\u003e\u003cstrong\u003es\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank the data abstractors from the Chinese Neonatal Network. We thank all the staff at the Chinese Neonatal Network coordinating center for providing organizational support (Lin Yuan, PhD; Tongling Yang, RN; Hao Yuan, RN; Li Wang, RN; Yulan Lu, PhD).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGroup Information of the Chinese Neonatal Network\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGroup Information of the Chinese Neonatal Network: Chairmen: Shoo K. Lee, MBBS, Mount Sinai Hospital, University of Toronto; Chao Chen, MD, Children’s Hospital of Fudan University. Vice-Chairmen: Lizhong Du, MD, Children's Hospital of Zhejiang University School of Medicine; Wenhao Zhou, Children’s Hospital of Fudan University.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSite principle investigators of the Chinese Neonatal Network: Children's Hospital of Fudan University: Yun Cao, MD; The Third Affiliated Hospital of Zhengzhou University: Xiuyong Chen, MD; Guangzhou Women and Children’s Medical Center: Huyan Zhang, MD; Tianjin Obstetrics \u0026amp; Gynecology Hospital: Xiuying Tian, MD; Gansu Provincial Maternity and Child Care Hospital: Jingyun Shi, MD; Northwest Women's and Children's Hospital: Zhankui Li, MD; Shenzhen Maternity and Child Health Care Hospital: Chuanzhong Yang, MD; Guizhou Women and Children’s Hospital: Ling Liu, MD; Suzhou Municipal Hospital affiliated to Nanjing Medical University: Zuming Yang, MD; Shengjing Hospital of China Medical University: Jianhua Fu, MD;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eChildren’s Hospital of Shanxi: Yong Ji, MD; Quanzhou Women and Children’s Hospital: Dongmei Chen, MD; Fujian Women and Children’s Medical Center: Changyi YANG, MD; Children’s Hospital of Nanjing Medical University: Rui Chen , MD; Hunan Children’s Hospital: Xiaoming Peng, MD; Qingdao Women and Children’s Hospital: Ruobing Shan, MD; Nanjing Maternity and Child Health Care Hospital: Shuping Han, MD; The First Bethune Hospital of Jilin University: Hui Wu, MD; The First Affiliated Hospital of Anhui Medical University: Lili WANG, MD; Women and Children's Hospital of Guangxi Zhuang Autonomous Region: Qiufen Wei, MD; The First Affiliated Hospital of Xinjiang Medical University: Mingxia Li, MD; Foshan Women and Children’s Hospital: Yiheng Dai, MD; The Affiliated Hospital of Qingdao University: Hong Jiang, MD; Henan Children’s Hospital: Wenqing Kang, MD; Children’s Hospital of Shanghai: Xiaohui Gong, MD; Chongqing Health Care Center for Women and Children: Xiaoyun Zhong, MD; Children’s Hospital of Chongqing Medical University: Yuan Shi, MD; Wuxi Maternity and Child Healthcare Hospital: Shanyu Jiang, MD; Children's Hospital of Soochow University: Bing Sun, MD; People's Hospital of Xinjiang Uygur Autonomous Region: Long Li, MD; Yuying Children's Hospital Affiliated to Wenzhou Medical University: Zhenlang Lin, MD; Shanghai First Maternity and Infant Hospital: Jiangqin Liu, MD; Anhui Provincial Hospital: Jiahua PAN, MD; Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine: Hongping Xia, MD; Qilu Children’s Hospital of Shandong University: Xiaoying Li, MD; The First Affiliated Hospital of Zhengzhou University: Falin Xu, MD; General Hospital of Ningxia Medical University: Yinping Qiu, MD; Hebei Children’s Hospital: Li Ma, MD; Hainan Women and Children’s Hospital: Ling Yang, MD; The second XiangYA hospital of Central South University:Xiaori He, MD; Ningbo Women\u0026amp;Children Hospital: Yanhong Li, MD; Xiamen Children’s Hospital: Deyi Zhuang, MD; Shaanxi Provincial People’s Hospital: Qin Zhang, MD; The Affiliated Hospital of Southwest Medical University: Wenbin Dong, MD; Shanghai Children’s Medical Center affiliated to Shanghai Jiaotong University School of Medicine: Jianhua Sun, MD; First Affiliated Hospital of Kunming Medical University: Kun Liang, MD; Changzhou Maternal and Children Health Care Hospital: Huaiyan Wang, MD; Shenzhen Children’s Hospital: Jinxing Feng, MD; Jiangxi Provincial Children’s Hospital: Liping Chen, MD; Xiamen Maternity and Child Health Care Hospital: Xinzhu Lin, MD; Zhuhai Center for Maternal and Child Health Care: Chunming Jiang, MD; Guangdong Women and Children's Hospital: Chuan Nie, MD; Wuhan Chidren's Hospital: Linkong Zeng, MD; Beijing Children's Hospital of Capital Medical University: Mingyan Hei, MD; Maternal and Children Hospital of Shaoxing: Hongdan Zhu, MD; The First People's Hospital of Yunnan Province: Hongying MI, MD; Dehong people's Hospital of Yunnan Province: Zhaoqing Yin, MD; First Affiliated Hospital of Xian Jiaotong University: Hongxia Song, MD; Inner Mongolia maternal and child health care hospital: Hongyun Wang, MD; Dalian Municipal Women and Children’s Medical Center: Dong Li, MD; Lianyungang Maternal and Children Health Hospital: Yan Gao , MD; Children's Hospital Affiliated to Capital Institute of Pediatrics: Yajuan Wang, MD; Anhui Children's Hoospital: Liying Dai, MD; Fuzhou Children’s Hospital of Fujian Province: Liyan ZHANG, MD; Kunming Children's Hospital: Yangfang Li, MD; Shenzhen Hospital of Hongkong University: Qianshen Zhang, MD; Peking Union Medical College Hospital: Guofang Ding, MD; Obstetrics \u0026amp; Gynecology Hospital of Fudan University : Jimei Wang, MD; The Affiliated Hospital of Guizhou Medical University: Xiaoxia Chen, MD; Qinghai Women and Children Hospital: Zhen Wang, MD; The International Peace Maternity \u0026amp; Child Health Hospital of China welfare institute: Zheng Tang, MD; Children's Hospital of Zhejiang University: Xiaolu Ma, MD; Inner Mongolia People's Hospital: Xiaomei Zhang, MD; Xiamen Humanity Hospital: Xiaolan Zhang, MD; Shanghai General Hospital: Fang Wu, MD; The First People's Hospital of Yinchuan: Yanxiang Chen, MD; The Third Hospital of Nanchang: Ying Wu, MD; Advisor: Joseph Ting, MBBS; University of Alberta.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBearak J, Popinchalk A, Ganatra B, Moller AB, Tun\u0026ccedil;alp \u0026Ouml;, Beavin C, et al. Unintended pregnancy and abortion by income, region, and the legal status of abortion: estimates from a comprehensive model for 1990\u0026ndash;2019. Lancet Glob Health. 2020;8(9):e1152\u0026ndash;61.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eConsensus of Chinese Experts on the Diagnosis and Treatment of Spontaneous Miscarriage. (2020 edition) [J]. Chinese Journal of Practical Gynecology and Obstetrics, 2020, 36(11): 1082\u0026ndash;1090.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSedgh G, Bearak J, Singh S, Bankole A, Popinchalk A, Ganatra B, et al. Abortion incidence between 1990 and 2014: global, regional, and subregional levels and trends. Lancet. 2016;388(10041):258\u0026ndash;67.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNational Health Commission. China health statistics yearbook. Beijing: China Union Medical University; 2020. (In Chinese).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWu S, Qiu H. 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Neonatal necrotizing enterocolitis. Therapeutic decisions based upon clinical staging. Ann Surg. 1978;187:1\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWalsh MC, Kliegman RM. Necrotizing enterocolitis-treatment based on staging creteria. Pediatr Clin N Am. 1986;33:179\u0026ndash;201.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBritish Association of Perinatal Medicine. Guidelines for good practice in the management of neonatal respiratory distress syndrome. London: BAPM; 1999.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBallard JL, Novak KK, Driver M. A simplified score for assessment of fetal maturation of newly born infants. J Pediatr. 1979;95:769\u0026ndash;74.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhu L, Zhang R, Zhang S, Shi W, Yan W, Wang X, et al. Chinese neonatal birth weight curve for different gestational age. Chin J Pediatr. 2015;53:97\u0026ndash;103.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIntrapartum management of intraamniotic infection. ACOG Committee Opinion 712. American College of Obstetricians and Gynecologists. Obstet Gynecol. 2017;130(2):e95\u0026ndash;101.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRedline RW, Faye-Petersen O, Heller D, Qureshi F, Savell V, Vogler C, et al. Amniotic infection syndrome: nosology and reproducibility of placental reaction patterns. Pediatr Dev Pathol. 2003;6(5):435\u0026ndash;48.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eInternational Association of Diabetes and Pregnancy Study Groups Consensus Panel, Metzger BE, Gabbe SG, Persson B, Buchanan TA, Catalano PA, et al. International association of diabetes and pregnancy study groups recommendations on the diagnosis and classification of hyperglycemia in pregnancy. Diabetes Care. 2010;33(3):676\u0026ndash;82.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKattah AG, Garovic VD. The management of hypertension in pregnancy. Adv Chronic Kidney Dis. 2013;20(3):229\u0026ndash;39.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWeintraub AY, Sergienko R, Harlev A, Holcberg G, Mazor M, Wiznitzer A, et al. An initial miscarriage is associated with adverse pregnancy outcomes in the following pregnancy. Am J Obstet Gynecol. 2011;205(3):e2861\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoreau C, Kaminski M, Ancel PY, Bouyer J, Escande B, Thiriez G, et al. Previous induced abortions and the risk of very preterm delivery: results of the EPIPAGE study. BJOG. 2005;112(4):430\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRich-Edwards J, Krieger N, Majzoub J, Zierler S, Lieberman E, Gillman M. 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J Immunol. 1998;160(2):545\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGunnarsdottir J, Stephansson O, Cnattingius S, Akerud H, Wikstr\u0026ouml;m AK. Risk of placental dysfunction disorders after prior miscarriages: a population-based study. Am J Obstet Gynecol. 2014;211(1):e341\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePlaisier M. Decidualisation and angiogenesis. Best Pract Res Clin Obstet Gynaecol. 2011;25(3):259\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBurton GJ, Jauniaux E. Placental oxidative stress: from miscarriage to preeclampsia. J Soc Gynecol Investig. 2004;11(6):342\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJauniaux E, Hempstock J, Greenwold N, Burton GJ. Trophoblastic oxidative stress in relation to temporal and regional differences in maternal placental blood flow in normal and abnormal early pregnancies. Am J Pathol. 2003;162(1):115\u0026ndash;25.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBall E, Bulmer JN, Ayis S, Lyall F, Robson SC. Late sporadic miscarriage is associated with abnormalities in spiral artery transformation and trophoblast invasion. J Pathol. 2006;208(4):535\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao Y, Zhang W, Tian X. Analysis of risk factors of early intraventricular hemorrhage in very-low-birth-weight premature infants: a single center retrospective study. BMC Pregnancy Childbirth. 2022;22(1):890.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSafe Abortion. Technical and Policy Guidance for Health Systems. 2nd ed. Geneva: World Health Organization; 2012.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Abortion, Neonatal outcome, Singletons, Mortality, Morbidity","lastPublishedDoi":"10.21203/rs.3.rs-4941021/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4941021/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eIt is unclear whether there is an association between maternal abortion history and neonatal outcomes of singleton very preterm infants (VPIs). We assess the association between maternal abortion history and neonatal outcome of VPIs in China.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eAll first parity singleton VPIs born at \u0026lt;\u0026thinsp;32 weeks gestational age (GA) who were admitted to neonatal intensive care units (NICU) participating in the Chinese Neonatal Network (CHNN) from 2019 to 2021 were included in the study. Multivariable logistic regression models were constructed to compare neonatal outcomes among infants with different maternal abortion histories after adjusting for confounders.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eA total of 7256 VPIs were included in this analysis. Overall, 3133 (43.2%) infants had positive maternal abortion history. The incidence of mortality or any major morbidity including respiratory distress syndrome (RDS), patent ductus arteriosus (PDA), intraventricular haemorrhage (IVH), IVH stage 3 or 4, moderate or severe bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), ROP stage 3, 4, or 5 tended to increase significantly with increasing number of maternal abortion histories from non-abortion group to \u0026ge;2 abortions group. Multivariable analysis showed that maternal abortion history was significantly associated with higher risks of mortality or any major morbidity (adjusted odds ratio [aOR] 1.15, 95% confidence interval [CI] 1.03\u0026ndash;1.29), RDS (aOR 1.22, 95%CI 1.08\u0026ndash;1.38), IVH (aOR 1.17, 95% CI 1.05\u0026ndash;1.31), and IVH stage 3 or 4 (aOR 1.27, 95% CI 1.01\u0026ndash;1.59). Risk increased with the number of abortions. VPIs of mothers with two or more abortions had the highest risk of mortality or any major morbidity (aOR 1.18, 95% CI 1.02\u0026ndash;1.36), RDS (aOR 1.35, 95% CI 1.18\u0026ndash;1.56), IVH (aOR 1.23, 95% CI 1.07\u0026ndash;1.43) and moderate or severe BPD (aOR 1.17, 95% CI 1.01\u0026ndash;1.36), compared to the non-abortion group.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eIn China, VPIs born to mothers with previous abortion history may have a greater risk of adverse outcomes. Based on the potential impact of maternal abortion history on newborns, it is necessary to provide additional information on related risks during antenatal counseling for these mothers.\u003c/p\u003e","manuscriptTitle":"Associations Between Maternal Abortion History and Neonatal Outcome among Very Preterm Infants：a multicenter cohort study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-10-17 09:22:12","doi":"10.21203/rs.3.rs-4941021/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-15T13:34:32+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"197872591213224546430177954751603134619","date":"2025-08-12T22:16:42+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-12T13:18:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"182148694897527039437539753416837061451","date":"2025-08-10T23:58:37+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"162302841732184506320380194919731891149","date":"2025-06-08T00:53:03+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-05T15:32:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"232439341568754759049409192398635107234","date":"2025-06-02T18:51:53+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-09-24T04:51:47+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-08-29T15:14:22+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-08-29T00:11:32+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-08-29T00:09:09+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pregnancy and Childbirth","date":"2024-08-19T23:32:52+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bb2debd0-158b-4b36-bf7f-5ef2186dfd93","owner":[],"postedDate":"October 17th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-10-13T16:00:28+00:00","versionOfRecord":{"articleIdentity":"rs-4941021","link":"https://doi.org/10.1186/s12884-025-08196-6","journal":{"identity":"bmc-pregnancy-and-childbirth","isVorOnly":false,"title":"BMC Pregnancy and Childbirth"},"publishedOn":"2025-10-06 15:57:26","publishedOnDateReadable":"October 6th, 2025"},"versionCreatedAt":"2024-10-17 09:22:12","video":"","vorDoi":"10.1186/s12884-025-08196-6","vorDoiUrl":"https://doi.org/10.1186/s12884-025-08196-6","workflowStages":[]},"version":"v1","identity":"rs-4941021","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4941021","identity":"rs-4941021","version":["v1"]},"buildId":"rHA-KDH7Qsr4HCuvH75dn","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}