Prenatal maternal inactivated COVID-19 vaccination: the maternal and neonatal outcomes, a retrospective cohort study

Prenatal maternal inactivated COVID-19 vaccination: the maternal and neonatal outcomes, a retrospective 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 Prenatal maternal inactivated COVID-19 vaccination: the maternal and neonatal outcomes, a retrospective cohort study Yaoyao Cai, Shenghao Wu, Sisi Zhang, Xinxin Xu, Fengfeng Xie, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-2710503/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background There are very few data on the maternal and neonatal safety effects of inactivated COVID-19 vaccines. Several studies have reported the safety of SARS-CoV-2 vaccination during pregnancy, with no adverse effect on maternal and neonatal outcomes. However, data on the safety of prenatal vaccination are scarce. Therefore, more relevant data are needed to inform maternal, pregnancy, and infant outcomes. Objective To evaluate the prenatal maternal inactivated COVID-19 vaccination and the impact on maternal and neonatal outcomes. Methods A retrospective cohort study among women who delivered between January and June 2022 at the first affiliated hospital of wenzhou medical university. Those who have completed at least one dose of inactivated vaccine before or during pregnancy were included in “vaccinated group”, and those who were not vaccinated were included in “unvaccinated group”, the maternal, pregnancy and neonatal outcomes were evaluated. Propensity score matching (PSM) was performed to balance the baseline parameters of the two groups. Results A total of 1926 women were enrolled in this study, 827 (42.94%) women were prenatally vaccinated, and 1099 (57.06%) unvaccinated. The gestational week of delivery were slightly smaller in the vaccinated group, 38.77 ± 1.83 weeks in the vaccinated group and 39.01 ± 1.45 weeks in the unvaccinated group. There was a higher rate of overall preterm delivery in the vaccinated group (aOR 1.638, 95% CI 1.108–2.422; p = 0.013; Table 3, Fig. 2), however, the probability of delivery before 34 weeks and before 32 weeks (early preterm delivery) were similar (p > 0.05). A total of 2009 infants were born, 851 in the vaccinated group and 1158 in the unvaccinated group. There were similar neonatal outcomes in the two groups. Conclusions Although we found a slightly smaller gestational week of delivery and a possible increased rate of late preterm birth in the vaccination group, there was no difference in mean neonatal weight, incidence of low birth weight infants and other neonatal adverse complications. Meanwhile, there was no difference in pregnancy and maternal outcomes between the two groups. COVID-19 Inactivated vaccine Maternal outcomes Pregnancy Neonatal outcomes Figures Figure 1 Figure 2 Introduction Over the last three years, the COVID-19 outbreaks and pandemics have caused catastrophic damage to health, economy, and all aspects of the society worldwide. Reported to WHO, there have been 754,018,841 confirmed cases of COVID-19, including 6,817,478 deaths[ 1 ]. To date, vaccination is the most important method to control pandemics. As of 30 January 2023, a total of 13,168,935,724 vaccine doses have been administered[ 1 ]. Despite the high coverage of COVID-19 vaccination, the potential for vaccine-induced adverse effects has not been fully elucidated, particularly in pregnant women who did not participate in the preliminary randomized controlled trial of COVID-19 vaccine safety and efficacy. Most of the current studies have shown that pregnant women with SARS-CoV-2 infection during pregnancy are not only at increased risk for critical condition, but also for pregnancy complications and adverse neonatal birth outcomes. Higher incidence of morbidity and mortality rates of SARS-CoV-2 infection in pregnancy have been reported in women of childbearing age compared to non-pregnant women[ 2 ]. In an exploratory surveillance study conducted in Canada from March 2020 to October 2021, SARS-CoV-2 infection during pregnancy was significantly associated with increased risk of adverse maternal outcomes and preterm birth, including increased risk of SARS-CoV-2 related hospitalization and a significantly increased risk of preterm birth[ 3 ]. Meanwhile, a meta-analysis showed there was no evidence of higher risk of adverse perinatal outcomes of COVID-19 vaccines during pregnancy. COVID-19 mRNA vaccination in pregnancy appears to be safe and is associated with a reduction in stillbirth[ 4 ]. As a multicentre retrospective cohort study shown, vaccination of the Covid-19 vaccine (BioNTech BNT162b2) during the third trimester of pregnancy was not associated with adverse maternal outcomes, moreover, it decreased the risk for neonatal adverse outcomes[ 5 ]. Results from another retrospective cohort study of all women who delivered at Soraka University Medical Center, the largest birthing center in Israel, showed no differences in pregnancy, delivery and neonatal complications, including gestational age at delivery, incidence of small for gestational age and neonatal respiratory complications, with or without Pfizer-BioNTech COVID-19 vaccination[ 6 ]. Therefore, an increasing number of countries are recommending vaccination of pregnant women with COVID-19 vaccine. In China, COVID-19 inactivated vaccine is widely promoted. Diffierent with the mRNA vaccines described above, these inactivated vaccines were developed based on the immune response induced by inactivated SARS-CoV-2 virus. There are very few data on the maternal and neonatal safety effects of inactivated COVID-19 vaccines. Therefore, more relevant data are needed to inform the outcome of mothers, pregnancies and infants. Our research aims to evaluate the prenatal maternal inactivated COVID-19 vaccination and the impact on adverse maternal and neonatal outcomes. Materials And Methods This was a retrospective cohort study, including all women who delivered between January and June 2022 at the First Affiliated Hospital of Wenzhou Medical University. Women who diagnosed with COVID-19 in the past, combined with severe heart disease, liver disease, kidney disease, cerebrovascular events, and malignant tumor, or with unknown vaccination status and pregnancy follow-up information were excluded. Among the enrolled cases, who have completed at least one dose of an inactivated vaccine before or during pregnancy were included in “vaccinated group”, and those who were not vaccinated were included in “unvaccinated group”. All the patients included in this study requested the vaccination voluntarily. The detailed flow chart was shown in Fig. 1 . Detailed vaccination status, including vaccine type, dose, date and manufacturer were ascertained using immunization records, which could be accessed through Zhejiang Province regional health information sharing platform from the electronic medical record system or their smartphone app such as Alipay, WeChat, the health codes of various provinces and cities. For each participating case, demographic characteristics regarding age, weight, height and reproductive history, assisted reproductive status, past medical history, maternal obstetric complications, delivery and newborn details were obtained by searching from the electronic medical record system of the hospital and manually recording. Fertility treatments included ovulation induction or in-vitro fertilization. Chorioammonitis refers to the cases confirmed by pathology, which was also included in Puerperal infection. Postpartum haemorrhage (PPH, estimated blood loss of > 1000 ml in Caesarean delivery, and > 500 ml in Vaginal delivery). Gestational hypertemsion (gHTN) was defined as an elevated SBP of ≥ 140 mmHg or a DBP of ≥ 90 mmHg occurring on two occasions at least 4h apart after 20 weeks of gestation, which is not associated with proteinuria and no signs or symptoms of end organ damage. Gestational diabetes mellitus (GDM) was defined as glucose intolerance of variable severity with onset or first recognition during pregnancy. Newborn digestive complications included neonatal intestinal obstruction, gastrointestinal dysfunction, allergic enteritis, and gastrointestinal bleeding in this study. Newborn respiratory complications included apnea, dyspnea, shortness of breath, respiratory failure, wet lung, pneumonia, and respiratory distress syndrome. Other composite adverse neonatal outcome refers to the comprehensive situation of multiple diseases related to premature delivery. Statistical analysis We compared the following aspects of the vaccinated group versus the unvaccinated group: baseline characteristics, complications during pregnancy, postpartum outcomes, and neonatal outcomes. Quantitative variables described by a normal distribution were presented as Mean ± Standard Deviation (M ± SD), and were presented as median (interquartile range) if not normally distributed. Differences in quantitative variables between the two groups were compared by Kruskal Wallis test. Categorical variables were presented with n(%) and differences between groups were compared using Chi-square test, and Fisher's exact test was used if the count variable had a theoretical number < 10. Considering the differences in baseline characteristics between eligible participants in the two groups (Table 1 ), propensity-score matching (PSM) was used to identify a cohort of patients with similar baseline characteristics. The propensity score was calculated by using a multiple logistic regression model, with vaccinated versus unvaccinated serving as the dependent variable, and parity, previous caesarean delivery and fertility treatments serving as independent variables. Matching was performed with the use of a 1:1 matching protocol, with a caliper width of 0.05 of the SD of the logit of the propensity score. SD were estimated for all the baseline covariates before and after matching, SD of less than 10.0% was considered to indicate a balance[ 7 ]. Multivariable logistic regression and multiple linear regression were applied to analyze the influence of COVID-19 vaccination on gestational age at delivery, gestational age at delivery < 37 weeks, LBW, VlBW and fetal macrosomia. The following confounding factors are adjusted in the model: female age, male age, parity, fertility treatments, previous caesarean delivery, BMI, previous miscarriages, pre-existing diabetes, hypothyroidism and hypertension. Table 1 Baseline characteristics of the vaccinated versus the unvaccinated group. Before PSM P value After PSM P value Features Vaccinated (n = 827) Unvaccinated (n = 1099) Vaccinated (n = 761) Unvaccinated (n = 761) Female Age, years 30.64 ± 4.77 30.52 ± 4.35 0.883 30.37 ± 4.67 30.39 ± 4.35 0.9366 Male Age, years 32.67 ± 5.19 32.45 ± 4.77 0.488 32.42 ± 5.09 32.33 ± 4.72 0.7301 Parity 1.70 ± 0.65 1.54 ± 0.65 < 0.001 1.66 ± 0.65 1.63 ± 0.65 0.4752 Previous miscarriages 0.70 ± 1.01 0.75 ± 1.05 0.331 0.68 ± 0.99 0.79 ± 1.10 0.0642 BMI, kg/m 2 21.46 ± 3.21 21.48 ± 3.19 0.642 21.39 ± 3.22 21.39 ± 3.14 0.9849 Previous caesarean delivery, any 178 (21.5%) 178 (16.2%) 0.003 113 (14.8%) 139 (18.3%) 0.0847 Fertility treatments 50 (6.1%) 256 (23.3%) < 0.001 50 (6.6%) 50 (6.6%) 1.0000 Pre-existing Hypothyroidism 19(2.3%) 33 (3.0%) 0.345 18 (2.4%) 17 (2.2%) 0.864 Pre-existing Diabetes 13 (1.6%) 15 (1.4%) 0.705 13 (1.7%) 10 (1.3%) 0.6720 Pre-existing hypertension 11 (1.3%) 16 (1.5%) 0.816 103 (13.5%) 114 (15.0%) 0.4635 IBM SPSS Statistics 21 (IBM SPSS, Turkey) program and EmpowerStats software (www.empowerstats.com; X&Y solutions, Inc., Boston MA) were used to analyze all the data. In all analyses, p < 0.05 were considered statistically significant. Results During the study period, there were 2036 deliveries in the first affiliated hospital of Wenzhou medical university. A total of 1926 (94.6%) women were enrolled in this study, after excluding patients with incomplete vaccination information, severe heart disease, hematologic disorders, severe liver and kidney disease and with malignant tumor. 827 (42.94%) women were prenatally vaccinated and included in the vaccinated group, and 1099 (57.06%) women were unvaccinated and included in the unvaccinated group. The flow chart of the study was shown in Fig. 1 . Women in the two groups had similar demographics, with the exception of parity, previous caesarean delivery and the ratio of fertility treatments (Table 1 ). We applied the PSM to balance the basic characteristics, and the results showed the baseline and previous obstetric characteristics were well balanced after PSM. The pregnancy and maternal outcomes were presented in Table 2 . After PSM, the gestational weeks of delivery were slightly smaller in the vaccinated group, 38.77 ± 1.83 weeks in the vaccinated group and 39.01 ± 1.45 weeks in the unvaccinated group. There was a higher rate of overall preterm delivery in the vaccinated group (aOR 1.638, 95% CI 1.108–2.422; p = 0.013; Table 3 , Fig. 2 ), however, the probability of delivery before 34 weeks and before 32 weeks (early preterm delivery) were similar (p > 0.05). The results reveal that there were similar rate of multifetal gestation, abnormal fetal presentation, cesarean section and forceps assisted delivery (p > 0.05). There were also similar maternal length of stay (p > 0.05) and similar rates of obstetric complications (p > 0.05) in the two groups, including postpartum hemorrhage, premature rupture of membranes, amniotic fluid contamination, hypoamniotic fluid, gestational hypertension, pre-eclampsia, gestational diabetes mellitus, hypothyroidism in pregnancy, placenta praevia and placental implantation. In addition, there were no diffierence in rate of reproductive tract infection (including mycoplasma infection, streptococcal infection and total incidence of various vaginitis) and puerperal infections during pregnancy (p > 0.05). In the vaccinated group, there was a higher incidence of polyhydramnios (p < 0.05), but the number of cases is relatively small(Table 2 ). Table 2 Pregnancy and maternal outcomes of the vaccinated versus the unvaccinated group. Before PSM P value After PSM P value Vaccinated (n = 827) Unvaccinated (n = 1099) Vaccinated (n = 761) Unvaccinated (n = 761) Multifetal gestation 24 (2.9%) 59 (5.4%) 0.008 24 (3.2%) 21 (2.8%) 0.7622 Gestational age at delivery 38.74 ± 1.81 38.89 ± 1.57 0.212 38.77 ± 1.83 39.01 ± 1.45 0.0044 Gestational age at delivery <32 weeks 9 (1.1%) 3 (0.3%) 0.024 9 (1.2%) 2 (0.3%) 0.0694 Gestational age at delivery <34 weeks 20 (2.4%) 16 (1.5%) 0.123 19 (2.5%) 9 (1.2%) 0.0860 Gestational age at delivery <37 weeks 83 (10.0%) 91 (8.3%) 0.183 75 (9.9%) 48 (6.3%) 0.0145 Abnormal fetal presentation 29 (3.5%) 53 (4.8%) 0.157 29 (3.8%) 30 (3.9%) 1.0000 Mode of delivery 0.014 0.1374 Caesarean delivery 294 (35.6%) 439 (40.0%) 0.049 238 (31.3%) 274 (36.0%) 0.0576 Vaginal delivery 512 (61.9%) 615 (56.0%) 0.009 502 (66.0%) 465 (61.1%) 0.0552 Forceps assisted delivery 21 (2.5%) 45 (4.1%) 0.063 21 (2.8%) 22 (2.9%) 1.0000 Postpartum hospital stay 3.73 ± 0.93 3.89 ± 1.28 0.004 3.72 ± 0.94 3.75 ± 0.95 0.5343 Puerperal infection 36 (4.4%) 59 (5.4%) 0.308 33 (4.3%) 37 (4.9%) 0.7135 Chorioamnionitis 14 (1.7%) 26 (2.4%) 0.305 13 (1.7%) 13 (1.7%) 1.0000 Postpartum haemorrhage 27 (3.3%) 38 (3.5%) 0.817 27 (3.5%) 27 (3.5%) 1.0000 Placental abruption 16 (1.9%) 14 (1.3%) 0.246 15 (2%) 12 (1.6%) 0.6977 Amniotic fluid pollution 95 (11.5%) 155 (14.1%) 0.091 88 (11.6%) 99 (13%) 0.4349 Premature rupture of membranes 181 (21.9%) 222 (20.2%) 0.368 173 (22.7%) 150 (19.7%) 0.1678 Polyhydramnios 8 (0.9%) 3 (0.3%) 0.045 8 (1.1%) 0 (0) 0.0131 Oligohydramnios 47 (5.7%) 78 (7.1%) 0.212 43 (5.7%) 50 (6.6%) 0.5208 Gestational hypertemsion 28 (3.4%) 41 (3.7%) 0.687 26 (3.4%) 28 (3.7%) 0.8898 Preeclampsia 23 (2.8%) 62 (5.7%) 0.002 23 (3%) 28 (3.7%) 0.5656 Gestational diabetes mellitus 129 (15.6%) 213 (19.4%) 0.032 111 (14.6%) 127 (16.6%) 0.259 Hypothyroidism during pregnancy 110 (13.3%) 173 (15.7%) 0.134 103 (13.5%) 114 (15%) 0.4635 Placenta previa or placenta implantation 2 (0.2%) 9 (0.8%) 0.096 2 (0.3%) 7 (0.9%) 0.1811 Mycoplasma infection during pregnancy 98 (11.9%) 114 (10.4%) 0.305 93 (12.2%) 78 (10.2%) 0.2558 GBS infection during pregnancy 90 (10.88%) 141 (12.83%) 0.193 85 (11.2%) 102 (13.4%) 0.2116 Vaginitis during pregnancy, any 183 (22.1%) 242 (22.0%) 0.955 172 (22.6%) 172 (22.6%) 1.0000 Table 3 Multivariate logistic regression analysis for the association between Covid-19 vaccination and preterm birth (adjusted odds ratio) P OR 95% CI Vaccine 0.013 1.638 1.108 2.422 Female Age, years 0.419 0.973 0.909 1.040 Male Age, years 0.625 1.015 0.956 1.078 Parity 0.001 0.583 0.422 0.805 Fertility treatments 0.000 0.305 0.175 0.533 Previous caesarean delivery, any 0.995 0.998 0.602 1.656 BMI, kg/m 2 0.002 0.916 0.867 0.969 Previous miscarriages 0.848 1.019 0.844 1.230 Pre-existing Diabetes 0.522 1.644 0.359 7.518 Pre-existing Hypothyroidism 0.655 0.883 0.513 1.522 Pre-existing hypertension 0.045 0.303 0.094 0.972 In this study, a total of 2009 infants were born, 851 in the vaccinated group and 1158 in the unvaccinated group. There were similar neonatal outcomes in the two groups before and after PSM. After propensity-score matching, there was no differernce in average weight of newborns, as well as the incidence of macrosomia (aOR = 0.836, 95% CI 0.551–1.268, P = 0.399), low birth weight (aOR = 1.367, 95% CI 0.943–1.983, P = 0.099) and very low birth weight infants (aOR = 1.709, 95% CI 0.618–4.731, P = 0.302) (Table 4 , Fig. 2 ). There was also no difference in the sex ratio of newborns (p > 0.05). There were similar neonatal mortality, hospitalization rate and length of newborn hospitalization in the two groups (p > 0.05). Further detailed data shows that, there were comparable newborn complications in the vaccinated versus the unvaccinated group, including the incidence of jaundice, birth asphyxia, newborn digestive complications, newborn respiratory complications, newborn fever, neonatal heart disease, sepsis, hypolycaemia, hyperglycemia, internal haemorrhage, feeding problems of newborn, aspiration syndrome and other composite adverse neonatal outcomes (p > 0.05) (Table 4 ). Table 4 Neonatal outcomes of the vaccinated versus the unvaccinated group Before PSM P value After PSM P value Vaccinated (n = 851) Unvaccinated (n = 1158) Vaccinated (n = 782) Unvaccinated (n = 785) Birth weight, g 3220.35 ± 528.64 3211.16 ± 538.42 0.653 3213.98 ± 530.77 3261.66 ± 498.57 0.137 Birthweight > 4000 g 43 (5.1%) 66 (5.7%) 0.527 39 (5.0%) 44 (5.6%) 0.561 Low birth weight, < 2500 g 65 (7.6%) 99 (8.6%) 0.461 63 (8.0%) 44 (5.6%) 0.060 Very low birth weight, < 1500 g 9 (1.1%) 13 (1.1%) 0.890 9 (1.2%) 5 (0.6%) 0.286 Male gender 447 (52.5%) 599 (51.7%) 0.723 410 (52.2%) 405 (51.8%) 0.862 5-minute Apgar score ≤ 7 1 (0.1%) 2 (0.2%) 1.000 1 (0.1%) 2 (0.3%) 0.624 All-cause hospitalizations 210 (24.7%) 328 (28.3%) 0.068 196 (25.0%) 209 (26.7%) 0.427 Length of newborn hospitalization, days 2.17 ± 5.69 2.57 ± 6.37 0.061 2.18 ± 5.74 2.17 ± 5.52 0.623 Infant death over the study period 1 (0.1%) 1 (0.1%) 0.828 1 (0.1%) 1 (0.1%) 0.998 Jaundice 82 (9.6%) 120 (10.4%) 0.592 76 (9.7%) 94 (12.0%) 0.137 Birth asphyxia 7 (0.8%) 8 (0.7%) 0.735 7 (0.9%) 2 (0.3%) 0.178 Newborn digestive complications 3 (0.4%) 9 (0.8%) 0.222 3 (0.4%) 5 (0.6%) 0.506 Newborn respiratory complications 37 (4.4%) 48 (4.2%) 0.823 36 (4.6%) 25 (3.2%) 0.155 Newborn fever 4 (0.5%) 10 (0.9%) 0.295 4 (0.5%) 6 (0.8%) 0.522 Neonatal heart disease 3 (0.4%) 4 (0.4%) 1.000 3 (0.4%) 3 (0.4%) 1.000 Sepsis 1 (0.1%) 6 (0.5%) 0.262 2 (0.3%) 5 (0.6%) 0.287 Hypoglycaemia 5 (0.6%) 8 (0.7%) 0.775 5 (0.6%) 7 (0.9%) 0.558 Hyperglycemia 0 (0.0%) 2 (0.2%) 0.511 0 (0.0%) 2 (0.3%) 0.249 Intracranial haemorrhage 0 (0.0%) 3 (0.3%) 0.267 0 (0.0%) 2 (0.3%) 0.249 Feeding problems of newborn 13 (1.5%) 13 (1.1%) 0.427 13 (1.7%) 7 (0.9%) 0.180 Aspiration syndrome 2 (0.2%) 8 (0.7%) 0.151 2 (0.3%) 5 (0.6%) 0.287 Other composite adverse neonatal outcome 54 (6.4%) 89 (7.7%) 0.248 48 (6.1%) 51 (6.5%) 0.740 Disscussion To our knowledge, this study is the first to focus on the impact of prenatal inactivated COVID-19 vaccination on maternal and neonatal outcomes. During the study period, 42.9% of women who delivered between 2022.01.01 and 2022.06.30 included in the study received at least one dose of vaccine before delivery. Women in the vaccinated group had a higher number of previous deliveries, a higher percentage of scarred uteruses, and a significantly lower percentage of fertility treatments. Because of these underlying imbalances, we performed multivariate regression analysis and PSM to control the confounding factors that might affect the results. In this study, we found no significant association between vaccination and severe adverse pregnancy outcomes or neonatal complications. Although we found a slightly smaller gestational week of delivery and a possible increased rate of late preterm birth in the vaccination group, there was no difference in mean neonatal weight, incidence of low birth weight infants and other neonatal adverse complications. Studies show that maternal and fetal outcomes worsened globally during the COVID-19 pandemic, with increases in maternal deaths, stillbirths, ruptured ectopic pregnancies, and maternal depression[ 8 ]. A meta-analysis revealed that pregnant women with SARS-CoV-2 infection were at higher risk of preterm delivery, requiring mechanical ventilation, admission to an intensive care unit and death compared to non-pregnant women[ 9 ]. As worsening symptoms of maternal infection may lead to more adverse neonatal outcomes. A cohort study involving 43 institutions in 18 countries found that comparing pregnant women with confirmed and undiagnosed COVID-19 identified that COVID-19 during pregnancy was associated with a substantial and sustained increase in severe maternal morbidity and mortality and neonatal complications. In addition, COVID-19 during pregnancy was associated with an increased risk of pregnancy-specific complications of pre-eclampsia, preterm delivery, and stillbirth[ 10 ]. Based on the special effects of SARS-CoV-2 infection on maternal and neonatal outcomes, most studies support the safety and protection of COVID-19 vaccine in pregnant women and their newborns[ 11 ], However, the problem is that there is still a lack of evidence on the safety of vaccination and its effects on maternal and neonatal outcomes. A meta-analysis evaluating evidence from 23 studies, including 117,552 pregnant women who received COVID-19 vaccine, showed that the effectiveness of mRNA vaccination was 89.5%. In the vaccinated cohort, the risk of stillbirth was significantly reduced by 15%[ 4 ]. Another study showed no differences in prenatal COVID-19 vaccination in terms of pregnancy, delivery, and neonatal complications, including gestational age at delivery, incidence of small for gestational age, and neonatal respiratory complications[ 12 ]. It has been reported that vaccination with covid-19 during pregnancy was not associated with a higher risk of preterm delivery, younger gestational age at birth, or risk of stillbirth[ 13 ]. A multicenter retrospective study showed that covid19 vaccination was not associated with maternal composite adverse outcomes and a significantly lower risk of neonatal composite adverse outcomes was observed[ 5 ]. However, almost all of these above studies and evidence are based on mRNA vaccination. In China, COVID-19 inactivated vaccine (coronavirus vaccine) is the main type of COVID-19 vaccine available. Studies have shown that COVID-19 inactivated vaccine (coronavirus vaccine) is effective in preventing the transmission of COVID-19, with an efficiency of 65.9% in preventing COVID-19 infection, 87.5% in avoiding hospitalization, 90.3% in preventing ICU hospitalization, and 86.3% in preventing COVID-19 death[ 14 ]. Prospective cohort studies have shown that treatment of adults with either of the two inactivated SARS-CoV-2 vaccines significantly reduces the risk of symptomatic COVID-19 with few serious adverse events[ 15 ]. However, there are no clinical data to determine whether inactivated vaccination of pregnant women may affect on maternal and neonatal outcomes or not. An animal study showed that human angiotensin-converting enzyme 2 (hACE2) mice vaccinated with inactivated COVID-19 vaccine before and during pregnancy exhibited normal body weight changes and reproductive performance indicators, and the physical development of their offspring was normal. Moreover, after intranasal vaccination with SARS-CoV-2, all pregnant mice in the immunized group survived, and the reproductive performance and physical development of their offspring were normal. In contrast, all mice in the non-immunized group died before delivery. This experiment may recommend that inactivated COVID-19 vaccination is safe and may effectively protects pregnant mice from SARS-CoV2 infection and has no adverse effects on offspring[ 16 ]. Huang etal. demonstrates that female vaccination with inactivated COVID-19 vaccine does not have any measurable deleterious effects on in vitro fertilization treatment and has no significant impact on embryonic laboratory parameters or pregnancy outcomes[ 17 ]. Another study on the prognosis of inactivated COVID-19 vaccine in frozen-thawed embryos for transfer revealed that live birth rates, sustained pregnancy rates and clinical pregnancy rates in vaccinated women were comparable to those in unvaccinated women, and birth length and birth weight were similar in both groups[ 18 ]. However, none of these studies reported maternal-related complications, and only birth weight was analyzed regarding neonatal outcomes. This study is the first to focus on the effects of prenatal inactivated COVID-19 vaccination on maternal and neonatal outcomes and to analyze the relevant outcomes in detail, with results largely similar to those of similar studies described above. However, it is worth noting that we found an increased risk of overall preterm birth in the vaccinated group compared to unvaccinated women (p < 0.05), and it is important to mention that there was no difference in early preterm birth (< 32 weeks) rate and incidence of preterm birth < 34 weeks, most preterm births were late preterm and there was no difference in neonatal outcomes. Although some studies have shown that vaccination does not increase the risk of preterm birth[ 6 ]. The study by Aharon Dick et al. had a similar outcome to ours, although their study population was vaccinated with mRNA vaccine. They included a larger sample and explored the association between risk of preterm birth and vaccination in early, midterm and late pregnancy separately. They found a higher risk of preterm delivery in those who were vaccinated in the midterm of pregnancy (8.1% vs. 6.2%).We therefore hypothesized that unmeasured confounding factors associated with vaccination may have contributed to the results[ 19 ]. A large sample size was included in our study, although this was a retrospective study, detailed and accurate vaccination information, including vaccine manufacturer, dosing date, and fertility treatment information were available with the help of an electronic health database to ensure the reliability and authenticity of the retrospective results. However, two limitations of the study should also be noted. First, due to the single-center retrospective nature of the study, some baseline clinical characteristics may not have been adequately balanced. Second, due to the limited sample size, we were unable to match by time of the first vaccination. In addition, early pregnancy outcomes such as miscarriage and ectopic pregnancy cannot be studied. Conclusions In this cohort study, the inactivated COVID-19 vaccine appeared to be safe, and although there was an increased incidence of late preterm delivery compared with unvaccinated women, there was no significant increase in other adverse maternal and neonatal outcomes. Future studies that focus on outcomes at the time of vaccination may provide better understanding and more accurate counseling of patients regarding the risks and benefits of vaccination before and during pregnancy. Declarations Ethics approval and consent to participate Hadassah’s Helsinki committee fle no. HMO-21-0342 approved a waiver of informed consent by participants due to the retrospective nature of the study and anonymization of personal information. All methods were performed in accordance with the relevant guidelines and regulations of the institutional ethical review board and in accordance with the Declaration of Helsinki. The study was approved by the independent Ethics Committee of the First Affiliated Hospital of Wenzhou Medical University (fle no: KY2023-R038) . Consent for publication Not applicable. Availability of Data and Material (ADM) The data presented in these studies are available on request from the corresponding author. Competing interests The authors declare no competing interests. Funding None Authors' contributions Conceptualization, Y.C.; methodology, Y.C. and W.X.; formal analysis, S.Z., F.X. and L.G.; data curation, X.X., S.W.,Y.C. and W.X.; writing—original draft preparation, Y.C. and W.X.; writing—review and editing, Y.C. , S.W and W.X.; supervision and project administration, W.X. All authors have read and agreed to the published version of the manuscript. Acknowledgment Not applicable. 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Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis. BMJ. 2020;370:m3320. Villar J, Ariff S, Gunier RB, Thiruvengadam R, Rauch S, Kholin A, et al. Maternal and Neonatal Morbidity and Mortality Among Pregnant Women With and Without COVID-19 Infection: The INTERCOVID Multinational Cohort Study. JAMA Pediatr. 2021;175(8):817-26. Rawal S, Tackett RL, Stone RH, Young HN. COVID-19 vaccination among pregnant people in the United States: a systematic review. Am J Obstet Gynecol MFM. 2022;4(4):100616. Wainstock T, Yoles I, Sergienko R, Sheiner E. Prenatal maternal COVID-19 vaccination and pregnancy outcomes. Vaccine. 2021;39(41):6037-40. Fell DB, Dimanlig-Cruz S, Regan AK, Haberg SE, Gravel CA, Oakley L, et al. Risk of preterm birth, small for gestational age at birth, and stillbirth after covid-19 vaccination during pregnancy: population based retrospective cohort study. BMJ. 2022;378:e071416. Jara A, Undurraga EA, Gonzalez C, Paredes F, Fontecilla T, Jara G, et al. Effectiveness of an Inactivated SARS-CoV-2 Vaccine in Chile. N Engl J Med. 2021;385(10):875-84. Al Kaabi N, Zhang Y, Xia S, Yang Y, Al Qahtani MM, Abdulrazzaq N, et al. Effect of 2 Inactivated SARS-CoV-2 Vaccines on Symptomatic COVID-19 Infection in Adults: A Randomized Clinical Trial. JAMA. 2021;326(1):35-45. Lin K, Liu M, Bao L, Lv Q, Zhu H, Li D, et al. Safety and protective capability of an inactivated SARS-CoV-2 vaccine on pregnancy, lactation and the growth of offspring in hACE2 mice. Vaccine. 2022;40(32):4609-16. Huang J, Xia L, Lin J, Liu B, Zhao Y, Xin C, et al. No Effect of Inactivated SARS-CoV-2 Vaccination on in vitro Fertilization Outcomes: A Propensity Score-Matched Study. J Inflamm Res. 2022;15:839-49. Cao M, Wu Y, Lin Y, Xu Z, Liang Z, Huang Q, et al. Inactivated Covid-19 vaccine did not undermine live birth and neonatal outcomes of women with frozen-thawed embryo transfer. Hum Reprod. 2022;37(12):2942-51. Dick A, Rosenbloom JI, Gutman-Ido E, Lessans N, Cahen-Peretz A, Chill HH. Safety of SARS-CoV-2 vaccination during pregnancy- obstetric outcomes from a large cohort study. BMC Pregnancy Childbirth. 2022;22(1):166. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-2710503","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":189765500,"identity":"fa4db54a-b90d-41f8-a559-ccd205ff42eb","order_by":0,"name":"Yaoyao Cai","email":"","orcid":"","institution":"the First Afffliated Hospital of Wenzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yaoyao","middleName":"","lastName":"Cai","suffix":""},{"id":189765501,"identity":"5b99f3ce-56e1-4c7f-9326-abe313eea532","order_by":1,"name":"Shenghao Wu","email":"","orcid":"","institution":"Yuying Children's Hospital of Wenzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Shenghao","middleName":"","lastName":"Wu","suffix":""},{"id":189765503,"identity":"c209d02b-1ba6-4a8d-9ecc-6b97adac6fb7","order_by":2,"name":"Sisi Zhang","email":"","orcid":"","institution":"the First Affiliated Hospital of Wenzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Sisi","middleName":"","lastName":"Zhang","suffix":""},{"id":189765505,"identity":"7590dd5a-d930-414a-97ab-21566fca600f","order_by":3,"name":"Xinxin Xu","email":"","orcid":"","institution":"Zhejiang University School of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Xinxin","middleName":"","lastName":"Xu","suffix":""},{"id":189765507,"identity":"aef20b74-5577-444b-a24b-62d0ecd51a4f","order_by":4,"name":"Fengfeng Xie","email":"","orcid":"","institution":"the First Afffliated Hospital of Wenzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Fengfeng","middleName":"","lastName":"Xie","suffix":""},{"id":189765509,"identity":"133f0504-20c5-4263-9692-a3a7e45389c9","order_by":5,"name":"Lijun Gao","email":"","orcid":"","institution":"the First Afffliated Hospital of Wenzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Lijun","middleName":"","lastName":"Gao","suffix":""},{"id":189765512,"identity":"b4ea7670-a01c-4075-a099-6d474fd9ba64","order_by":6,"name":"Weiting Xia","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAy0lEQVRIiWNgGAWjYBACfvbGxgcf/0jIybM3EKlFsudws+HMBhtjw54DRGoxuJHeJs3bkJbIcCOBWFtmJDZI8O44nMA48/HGGww1NtEEtfDzPGwwkDxzOI9dOq3YguFYWm4DQVvaExsSDNgOFzPOzjGTYGw4TFiLwYHEhgMJbIcTG26eIVbLicTGhoNtaYkNN3iI1CLZc7CZseEMKJCBfkkgxi/87O3Pf/+pAEXl4Y03PtTYENaC4kiJBFKUQ7SQqmMUjIJRMApGBgAAovBHIjKPYfsAAAAASUVORK5CYII=","orcid":"","institution":"the First Affiliated Hospital of Wenzhou Medical University","correspondingAuthor":true,"prefix":"","firstName":"Weiting","middleName":"","lastName":"Xia","suffix":""}],"badges":[],"createdAt":"2023-03-19 12:29:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-2710503/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-2710503/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":35543723,"identity":"8c3601af-ffe0-4dec-a4aa-6b993ac8027c","added_by":"auto","created_at":"2023-04-10 17:39:55","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":123118,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart of the study.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-2710503/v1/5b28b01d853d59c4bc544323.png"},{"id":35543722,"identity":"7a54f6b4-23ce-4536-93b7-f5cfe4499df8","added_by":"auto","created_at":"2023-04-10 17:39:54","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":637751,"visible":true,"origin":"","legend":"\u003cp\u003eLogistic regression of the maternal and neonatal outcomes in vaccinated women versus unvaccinated group. Adjusted for female age, male age, parity, fertility treatments, previous caesarean delivery, BMI, previous miscarriages, pre-existing diabetes, hypothyroidism and hypertension; OR, odds ratio.\u003c/p\u003e","description":"","filename":"figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-2710503/v1/387097f79bcb950c266af4f4.png"},{"id":43250463,"identity":"4ab67c84-6858-4852-93a4-2ad9dda816e9","added_by":"auto","created_at":"2023-09-17 08:37:21","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":598127,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2710503/v1/c730b6d9-bb63-458b-9209-369257ace798.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Prenatal maternal inactivated COVID-19 vaccination: the maternal and neonatal outcomes, a retrospective cohort study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eOver the last three years, the COVID-19 outbreaks and pandemics have caused catastrophic damage to health, economy, and all aspects of the society worldwide. Reported to WHO, there have been 754,018,841 confirmed cases of COVID-19, including 6,817,478 deaths[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. To date, vaccination is the most important method to control pandemics. As of 30 January 2023, a total of 13,168,935,724 vaccine doses have been administered[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Despite the high coverage of COVID-19 vaccination, the potential for vaccine-induced adverse effects has not been fully elucidated, particularly in pregnant women who did not participate in the preliminary randomized controlled trial of COVID-19 vaccine safety and efficacy.\u003c/p\u003e \u003cp\u003eMost of the current studies have shown that pregnant women with SARS-CoV-2 infection during pregnancy are not only at increased risk for critical condition, but also for pregnancy complications and adverse neonatal birth outcomes. Higher incidence of morbidity and mortality rates of SARS-CoV-2 infection in pregnancy have been reported in women of childbearing age compared to non-pregnant women[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. In an exploratory surveillance study conducted in Canada from March 2020 to October 2021, SARS-CoV-2 infection during pregnancy was significantly associated with increased risk of adverse maternal outcomes and preterm birth, including increased risk of SARS-CoV-2 related hospitalization and a significantly increased risk of preterm birth[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Meanwhile, a meta-analysis showed there was no evidence of higher risk of adverse perinatal outcomes of COVID-19 vaccines during pregnancy. COVID-19 mRNA vaccination in pregnancy appears to be safe and is associated with a reduction in stillbirth[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. As a multicentre retrospective cohort study shown, vaccination of the Covid-19 vaccine (BioNTech BNT162b2) during the third trimester of pregnancy was not associated with adverse maternal outcomes, moreover, it decreased the risk for neonatal adverse outcomes[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eResults from another retrospective cohort study of all women who delivered at Soraka University Medical Center, the largest birthing center in Israel, showed no differences in pregnancy, delivery and neonatal complications, including gestational age at delivery, incidence of small for gestational age and neonatal respiratory complications, with or without Pfizer-BioNTech COVID-19 vaccination[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Therefore, an increasing number of countries are recommending vaccination of pregnant women with COVID-19 vaccine.\u003c/p\u003e \u003cp\u003eIn China, COVID-19 inactivated vaccine is widely promoted. Diffierent with the mRNA vaccines described above, these inactivated vaccines were developed based on the immune response induced by inactivated SARS-CoV-2 virus. There are very few data on the maternal and neonatal safety effects of inactivated COVID-19 vaccines. Therefore, more relevant data are needed to inform the outcome of mothers, pregnancies and infants. Our research aims to evaluate the prenatal maternal inactivated COVID-19 vaccination and the impact on adverse maternal and neonatal outcomes.\u003c/p\u003e"},{"header":"Materials And Methods","content":"\u003cp\u003eThis was a retrospective cohort study, including all women who delivered between January and June 2022 at the First Affiliated Hospital of Wenzhou Medical University. Women who diagnosed with COVID-19 in the past, combined with severe heart disease, liver disease, kidney disease, cerebrovascular events, and malignant tumor, or with unknown vaccination status and pregnancy follow-up information were excluded. Among the enrolled cases, who have completed at least one dose of an inactivated vaccine before or during pregnancy were included in \u0026ldquo;vaccinated group\u0026rdquo;, and those who were not vaccinated were included in \u0026ldquo;unvaccinated group\u0026rdquo;. All the patients included in this study requested the vaccination voluntarily. The detailed flow chart was shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eDetailed vaccination status, including vaccine type, dose, date and manufacturer were ascertained using immunization records, which could be accessed through Zhejiang Province regional health information sharing platform from the electronic medical record system or their smartphone app such as Alipay, WeChat, the health codes of various provinces and cities. For each participating case, demographic characteristics regarding age, weight, height and reproductive history, assisted reproductive status, past medical history, maternal obstetric complications, delivery and newborn details were obtained by searching from the electronic medical record system of the hospital and manually recording.\u003c/p\u003e \u003cp\u003eFertility treatments included ovulation induction or in-vitro fertilization. Chorioammonitis refers to the cases confirmed by pathology, which was also included in Puerperal infection. Postpartum haemorrhage (PPH, estimated blood loss of \u0026gt;\u0026thinsp;1000 ml in Caesarean delivery, and \u0026gt;\u0026thinsp;500 ml in Vaginal delivery). Gestational hypertemsion (gHTN) was defined as an elevated SBP of \u0026ge;\u0026thinsp;140 mmHg or a DBP of \u0026ge;\u0026thinsp;90 mmHg occurring on two occasions at least 4h apart after 20 weeks of gestation, which is not associated with proteinuria and no signs or symptoms of end organ damage. Gestational diabetes mellitus (GDM) was defined as glucose intolerance of variable severity with onset or first recognition during pregnancy. Newborn digestive complications included neonatal intestinal obstruction, gastrointestinal dysfunction, allergic enteritis, and gastrointestinal bleeding in this study. Newborn respiratory complications included apnea, dyspnea, shortness of breath, respiratory failure, wet lung, pneumonia, and respiratory distress syndrome. Other composite adverse neonatal outcome refers to the comprehensive situation of multiple diseases related to premature delivery.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eWe compared the following aspects of the vaccinated group versus the unvaccinated group: baseline characteristics, complications during pregnancy, postpartum outcomes, and neonatal outcomes. Quantitative variables described by a normal distribution were presented as Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;Standard Deviation (M\u0026thinsp;\u0026plusmn;\u0026thinsp;SD), and were presented as median (interquartile range) if not normally distributed. Differences in quantitative variables between the two groups were compared by Kruskal Wallis test. Categorical variables were presented with n(%) and differences between groups were compared using Chi-square test, and Fisher's exact test was used if the count variable had a theoretical number\u0026thinsp;\u0026lt;\u0026thinsp;10.\u003c/p\u003e \u003cp\u003eConsidering the differences in baseline characteristics between eligible participants in the two groups (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), propensity-score matching (PSM) was used to identify a cohort of patients with similar baseline characteristics. The propensity score was calculated by using a multiple logistic regression model, with vaccinated versus unvaccinated serving as the dependent variable, and parity, previous caesarean delivery and fertility treatments serving as independent variables. Matching was performed with the use of a 1:1 matching protocol, with a caliper width of 0.05 of the SD of the logit of the propensity score. SD were estimated for all the baseline covariates before and after matching, SD of less than 10.0% was considered to indicate a balance[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Multivariable logistic regression and multiple linear regression were applied to analyze the influence of COVID-19 vaccination on gestational age at delivery, gestational age at delivery\u0026thinsp;\u0026lt;\u0026thinsp;37 weeks, LBW, VlBW and fetal macrosomia. The following confounding factors are adjusted in the model: female age, male age, parity, fertility treatments, previous caesarean delivery, BMI, previous miscarriages, pre-existing diabetes, hypothyroidism and hypertension.\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\u003eBaseline characteristics of the vaccinated versus the unvaccinated group.\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\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eBefore PSM\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003cp\u003evalue\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003eAfter PSM\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003cp\u003evalue\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFeatures\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;827)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eUnvaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;1099)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eVaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;761)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eUnvaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;761)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale Age, years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30.64\u0026thinsp;\u0026plusmn;\u0026thinsp;4.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.52\u0026thinsp;\u0026plusmn;\u0026thinsp;4.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.883\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30.37\u0026thinsp;\u0026plusmn;\u0026thinsp;4.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e30.39\u0026thinsp;\u0026plusmn;\u0026thinsp;4.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.9366\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale Age, years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e32.67\u0026thinsp;\u0026plusmn;\u0026thinsp;5.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.45\u0026thinsp;\u0026plusmn;\u0026thinsp;4.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.488\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e32.42\u0026thinsp;\u0026plusmn;\u0026thinsp;5.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e32.33\u0026thinsp;\u0026plusmn;\u0026thinsp;4.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.7301\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.4752\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrevious miscarriages\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.70\u0026thinsp;\u0026plusmn;\u0026thinsp;1.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.75\u0026thinsp;\u0026plusmn;\u0026thinsp;1.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.331\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.79\u0026thinsp;\u0026plusmn;\u0026thinsp;1.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0642\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI, kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.46\u0026thinsp;\u0026plusmn;\u0026thinsp;3.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21.48\u0026thinsp;\u0026plusmn;\u0026thinsp;3.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.642\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e21.39\u0026thinsp;\u0026plusmn;\u0026thinsp;3.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e21.39\u0026thinsp;\u0026plusmn;\u0026thinsp;3.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.9849\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrevious caesarean delivery, any\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e178 (21.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e178\u003c/p\u003e \u003cp\u003e(16.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e113\u003c/p\u003e \u003cp\u003e(14.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e139\u003c/p\u003e \u003cp\u003e(18.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0847\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFertility treatments\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50\u003c/p\u003e \u003cp\u003e(6.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e256\u003c/p\u003e \u003cp\u003e(23.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e50\u003c/p\u003e \u003cp\u003e(6.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e50\u003c/p\u003e \u003cp\u003e(6.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.0000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePre-existing Hypothyroidism\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19(2.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33\u003c/p\u003e \u003cp\u003e(3.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.345\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e18\u003c/p\u003e \u003cp\u003e(2.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e17\u003c/p\u003e \u003cp\u003e(2.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.864\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePre-existing Diabetes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13\u003c/p\u003e \u003cp\u003e(1.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003cp\u003e(1.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.705\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13\u003c/p\u003e \u003cp\u003e(1.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e10\u003c/p\u003e \u003cp\u003e(1.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.6720\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePre-existing hypertension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11\u003c/p\u003e \u003cp\u003e(1.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16\u003c/p\u003e \u003cp\u003e(1.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.816\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e103 (13.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e114\u003c/p\u003e \u003cp\u003e(15.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.4635\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIBM SPSS Statistics 21 (IBM SPSS, Turkey) program and EmpowerStats software (www.empowerstats.com; X\u0026amp;Y solutions, Inc., Boston MA) were used to analyze all the data. In all analyses, p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 were considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eDuring the study period, there were 2036 deliveries in the first affiliated hospital of Wenzhou medical university. A total of 1926 (94.6%) women were enrolled in this study, after excluding patients with incomplete vaccination information, severe heart disease, hematologic disorders, severe liver and kidney disease and with malignant tumor. 827 (42.94%) women were prenatally vaccinated and included in the vaccinated group, and 1099 (57.06%) women were unvaccinated and included in the unvaccinated group. The flow chart of the study was shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Women in the two groups had similar demographics, with the exception of parity, previous caesarean delivery and the ratio of fertility treatments (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). We applied the PSM to balance the basic characteristics, and the results showed the baseline and previous obstetric characteristics were well balanced after PSM.\u003c/p\u003e \u003cp\u003eThe pregnancy and maternal outcomes were presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. After PSM, the gestational weeks of delivery were slightly smaller in the vaccinated group, 38.77\u0026thinsp;\u0026plusmn;\u0026thinsp;1.83 weeks in the vaccinated group and 39.01\u0026thinsp;\u0026plusmn;\u0026thinsp;1.45 weeks in the unvaccinated group. There was a higher rate of overall preterm delivery in the vaccinated group (aOR 1.638, 95% CI 1.108\u0026ndash;2.422; p\u0026thinsp;=\u0026thinsp;0.013; Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), however, the probability of delivery before 34 weeks and before 32 weeks (early preterm delivery) were similar (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). The results reveal that there were similar rate of multifetal gestation, abnormal fetal presentation, cesarean section and forceps assisted delivery (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). There were also similar maternal length of stay (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05) and similar rates of obstetric complications (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05) in the two groups, including postpartum hemorrhage, premature rupture of membranes, amniotic fluid contamination, hypoamniotic fluid, gestational hypertension, pre-eclampsia, gestational diabetes mellitus, hypothyroidism in pregnancy, placenta praevia and placental implantation. In addition, there were no diffierence in rate of reproductive tract infection (including mycoplasma infection, streptococcal infection and total incidence of various vaginitis) and puerperal infections during pregnancy (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). In the vaccinated group, there was a higher incidence of polyhydramnios (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05), but the number of cases is relatively small(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\u003ePregnancy and maternal outcomes of the vaccinated versus the unvaccinated group.\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\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eBefore PSM\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003cp\u003evalue\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003eAfter PSM\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003cp\u003evalue\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;827)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eUnvaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;1099)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eVaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;761)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eUnvaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;761)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMultifetal gestation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24 (2.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e59 (5.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e24 (3.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e21 (2.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.7622\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGestational age at delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38.74\u0026thinsp;\u0026plusmn;\u0026thinsp;1.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38.89\u0026thinsp;\u0026plusmn;\u0026thinsp;1.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.212\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e38.77\u0026thinsp;\u0026plusmn;\u0026thinsp;1.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e39.01\u0026thinsp;\u0026plusmn;\u0026thinsp;1.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0044\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGestational age at delivery \u0026lt;32 weeks\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (1.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (0.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.024\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9 (1.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2 (0.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0694\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGestational age at delivery \u0026lt;34 weeks\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20 (2.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16 (1.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.123\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e19 (2.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9 (1.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0860\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGestational age at delivery \u0026lt;37 weeks\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e83\u003c/p\u003e \u003cp\u003e(10.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e91\u003c/p\u003e \u003cp\u003e(8.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.183\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e75\u003c/p\u003e \u003cp\u003e(9.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e48\u003c/p\u003e \u003cp\u003e(6.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0145\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAbnormal fetal presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29\u003c/p\u003e \u003cp\u003e(3.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e53\u003c/p\u003e \u003cp\u003e(4.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.157\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29\u003c/p\u003e \u003cp\u003e(3.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e30\u003c/p\u003e \u003cp\u003e(3.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.0000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMode of delivery\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\u003e0.014\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\u003e0.1374\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCaesarean delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e294 (35.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e439\u003c/p\u003e \u003cp\u003e(40.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.049\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e238 (31.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e274\u003c/p\u003e \u003cp\u003e(36.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0576\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVaginal delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e512 (61.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e615\u003c/p\u003e \u003cp\u003e(56.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.009\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e502\u003c/p\u003e \u003cp\u003e(66.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e465\u003c/p\u003e \u003cp\u003e(61.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0552\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eForceps assisted delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003cp\u003e(2.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45\u003c/p\u003e \u003cp\u003e(4.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.063\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e21\u003c/p\u003e \u003cp\u003e(2.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e22\u003c/p\u003e \u003cp\u003e(2.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.0000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostpartum hospital stay\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.89\u0026thinsp;\u0026plusmn;\u0026thinsp;1.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.75\u0026thinsp;\u0026plusmn;\u0026thinsp;0.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.5343\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePuerperal infection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36\u003c/p\u003e \u003cp\u003e(4.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e59\u003c/p\u003e \u003cp\u003e(5.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.308\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e33\u003c/p\u003e \u003cp\u003e(4.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e37\u003c/p\u003e \u003cp\u003e(4.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.7135\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\u003e14\u003c/p\u003e \u003cp\u003e(1.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26\u003c/p\u003e \u003cp\u003e(2.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.305\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13\u003c/p\u003e \u003cp\u003e(1.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13\u003c/p\u003e \u003cp\u003e(1.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.0000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostpartum haemorrhage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27\u003c/p\u003e \u003cp\u003e(3.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38\u003c/p\u003e \u003cp\u003e(3.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.817\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e27\u003c/p\u003e \u003cp\u003e(3.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e27\u003c/p\u003e \u003cp\u003e(3.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.0000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePlacental abruption\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16\u003c/p\u003e \u003cp\u003e(1.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14\u003c/p\u003e \u003cp\u003e(1.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.246\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e15\u003c/p\u003e \u003cp\u003e(2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12\u003c/p\u003e \u003cp\u003e(1.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.6977\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAmniotic fluid pollution\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e95\u003c/p\u003e \u003cp\u003e(11.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e155\u003c/p\u003e \u003cp\u003e(14.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.091\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e88 (11.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e99\u003c/p\u003e \u003cp\u003e(13%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.4349\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePremature rupture of membranes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e181 (21.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e222\u003c/p\u003e \u003cp\u003e(20.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.368\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e173 (22.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e150\u003c/p\u003e \u003cp\u003e(19.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.1678\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePolyhydramnios\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8\u003c/p\u003e \u003cp\u003e(0.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003cp\u003e(0.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.045\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8\u003c/p\u003e \u003cp\u003e(1.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e(0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0131\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOligohydramnios\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e47\u003c/p\u003e \u003cp\u003e(5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e78\u003c/p\u003e \u003cp\u003e(7.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.212\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e43\u003c/p\u003e \u003cp\u003e(5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e50\u003c/p\u003e \u003cp\u003e(6.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.5208\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGestational hypertemsion\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28\u003c/p\u003e \u003cp\u003e(3.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e41\u003c/p\u003e \u003cp\u003e(3.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.687\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e26\u003c/p\u003e \u003cp\u003e(3.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e28\u003c/p\u003e \u003cp\u003e(3.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.8898\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePreeclampsia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003cp\u003e(2.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e62\u003c/p\u003e \u003cp\u003e(5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e23\u003c/p\u003e \u003cp\u003e(3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e28\u003c/p\u003e \u003cp\u003e(3.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.5656\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGestational diabetes mellitus\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e129 (15.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e213\u003c/p\u003e \u003cp\u003e(19.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.032\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e111 (14.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e127\u003c/p\u003e \u003cp\u003e(16.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.259\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypothyroidism during pregnancy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e110 (13.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e173\u003c/p\u003e \u003cp\u003e(15.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.134\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e103 (13.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e114\u003c/p\u003e \u003cp\u003e(15%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.4635\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePlacenta previa or placenta implantation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2\u003c/p\u003e \u003cp\u003e(0.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9\u003c/p\u003e \u003cp\u003e(0.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.096\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2 (0.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7 (0.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.1811\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMycoplasma infection during pregnancy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e98\u003c/p\u003e \u003cp\u003e(11.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e114\u003c/p\u003e \u003cp\u003e(10.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.305\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e93 (12.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e78\u003c/p\u003e \u003cp\u003e(10.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.2558\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGBS infection during pregnancy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e90 (10.88%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e141 (12.83%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.193\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e85 (11.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e102\u003c/p\u003e \u003cp\u003e(13.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.2116\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVaginitis during pregnancy, any\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e183 (22.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e242 (22.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.955\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e172 (22.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e172\u003c/p\u003e \u003cp\u003e(22.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.0000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMultivariate logistic regression analysis for the association between Covid-19 vaccination and preterm birth (adjusted odds ratio)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOR\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003e95% CI\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVaccine\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.013\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.638\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.108\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2.422\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale Age, years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.419\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.973\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.909\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.040\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale Age, years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.625\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.015\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.956\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.078\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.583\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.422\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.805\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFertility treatments\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.305\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.175\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.533\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrevious caesarean delivery, any\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.995\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.998\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.602\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.656\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI, kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.916\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.867\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.969\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrevious miscarriages\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.848\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.019\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.844\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.230\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePre-existing Diabetes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.522\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.644\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.359\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e7.518\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePre-existing Hypothyroidism\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.655\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.883\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.513\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.522\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePre-existing hypertension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.045\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.303\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.094\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.972\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn this study, a total of 2009 infants were born, 851 in the vaccinated group and 1158 in the unvaccinated group. There were similar neonatal outcomes in the two groups before and after PSM. After propensity-score matching, there was no differernce in average weight of newborns, as well as the incidence of macrosomia (aOR\u0026thinsp;=\u0026thinsp;0.836, 95% CI 0.551\u0026ndash;1.268, P\u0026thinsp;=\u0026thinsp;0.399), low birth weight (aOR\u0026thinsp;=\u0026thinsp;1.367, 95% CI 0.943\u0026ndash;1.983, P\u0026thinsp;=\u0026thinsp;0.099) and very low birth weight infants (aOR\u0026thinsp;=\u0026thinsp;1.709, 95% CI 0.618\u0026ndash;4.731, P\u0026thinsp;=\u0026thinsp;0.302) (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). There was also no difference in the sex ratio of newborns (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). There were similar neonatal mortality, hospitalization rate and length of newborn hospitalization in the two groups (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). Further detailed data shows that, there were comparable newborn complications in the vaccinated versus the unvaccinated group, including the incidence of jaundice, birth asphyxia, newborn digestive complications, newborn respiratory complications, newborn fever, neonatal heart disease, sepsis, hypolycaemia, hyperglycemia, internal haemorrhage, feeding problems of newborn, aspiration syndrome and other composite adverse neonatal outcomes (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (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\u003eNeonatal outcomes of the vaccinated versus the unvaccinated group\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\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eBefore PSM\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003cp\u003evalue\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003eAfter PSM\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003cp\u003evalue\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;851)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eUnvaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;1158)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eVaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;782)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eUnvaccinated\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;785)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBirth weight, g\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3220.35\u0026thinsp;\u0026plusmn;\u0026thinsp;528.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3211.16\u0026thinsp;\u0026plusmn;\u0026thinsp;538.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.653\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3213.98\u0026thinsp;\u0026plusmn;\u0026thinsp;530.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3261.66\u0026thinsp;\u0026plusmn;\u0026thinsp;498.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.137\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBirthweight\u0026thinsp;\u0026gt;\u0026thinsp;4000 g\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e43 (5.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e66 (5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.527\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e39 (5.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e44 (5.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.561\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLow birth weight, \u0026lt;\u0026thinsp;2500 g\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e65 (7.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e99 (8.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.461\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e63 (8.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e44 (5.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.060\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVery low birth weight, \u0026lt;\u0026thinsp;1500 g\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (1.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13 (1.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.890\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9 (1.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5 (0.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.286\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale gender\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e447 (52.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e599\u003c/p\u003e \u003cp\u003e(51.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.723\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e410 (52.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e405\u003c/p\u003e \u003cp\u003e(51.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.862\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5-minute Apgar score\u0026thinsp;\u0026le;\u0026thinsp;7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003cp\u003e(0.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003cp\u003e(0.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003cp\u003e(0.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2\u003c/p\u003e \u003cp\u003e(0.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.624\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAll-cause hospitalizations\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e210 (24.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e328\u003c/p\u003e \u003cp\u003e(28.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.068\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e196 (25.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e209\u003c/p\u003e \u003cp\u003e(26.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.427\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLength of newborn hospitalization, days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.17\u0026thinsp;\u0026plusmn;\u0026thinsp;5.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.57\u0026thinsp;\u0026plusmn;\u0026thinsp;6.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.061\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.18\u0026thinsp;\u0026plusmn;\u0026thinsp;5.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.17\u0026thinsp;\u0026plusmn;\u0026thinsp;5.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.623\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInfant death over the study period\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003cp\u003e(0.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003cp\u003e(0.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.828\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003cp\u003e(0.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003cp\u003e(0.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.998\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eJaundice\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e82\u003c/p\u003e \u003cp\u003e(9.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e120\u003c/p\u003e \u003cp\u003e(10.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.592\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e76\u003c/p\u003e \u003cp\u003e(9.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e94\u003c/p\u003e \u003cp\u003e(12.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.137\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBirth asphyxia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7\u003c/p\u003e \u003cp\u003e(0.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003cp\u003e(0.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.735\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7\u003c/p\u003e \u003cp\u003e(0.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2\u003c/p\u003e \u003cp\u003e(0.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.178\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNewborn digestive complications\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003cp\u003e(0.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9\u003c/p\u003e \u003cp\u003e(0.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.222\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3\u003c/p\u003e \u003cp\u003e(0.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e(0.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.506\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNewborn respiratory complications\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e37\u003c/p\u003e \u003cp\u003e(4.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e48\u003c/p\u003e \u003cp\u003e(4.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.823\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e36\u003c/p\u003e \u003cp\u003e(4.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e25\u003c/p\u003e \u003cp\u003e(3.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.155\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNewborn fever\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4\u003c/p\u003e \u003cp\u003e(0.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003cp\u003e(0.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.295\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003cp\u003e(0.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6\u003c/p\u003e \u003cp\u003e(0.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.522\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNeonatal heart disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003cp\u003e(0.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4\u003c/p\u003e \u003cp\u003e(0.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3\u003c/p\u003e \u003cp\u003e(0.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3\u003c/p\u003e \u003cp\u003e(0.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSepsis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003cp\u003e(0.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003cp\u003e(0.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.262\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2\u003c/p\u003e \u003cp\u003e(0.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e(0.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.287\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypoglycaemia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e(0.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003cp\u003e(0.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.775\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e(0.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7\u003c/p\u003e \u003cp\u003e(0.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.558\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHyperglycemia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e(0.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003cp\u003e(0.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.511\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e(0.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2\u003c/p\u003e \u003cp\u003e(0.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.249\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntracranial haemorrhage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e(0.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003cp\u003e(0.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.267\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e(0.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2\u003c/p\u003e \u003cp\u003e(0.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.249\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFeeding problems of newborn\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13\u003c/p\u003e \u003cp\u003e(1.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13\u003c/p\u003e \u003cp\u003e(1.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.427\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13\u003c/p\u003e \u003cp\u003e(1.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7\u003c/p\u003e \u003cp\u003e(0.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.180\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAspiration syndrome\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2\u003c/p\u003e \u003cp\u003e(0.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003cp\u003e(0.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.151\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2\u003c/p\u003e \u003cp\u003e(0.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e(0.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.287\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOther composite adverse neonatal outcome\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e54\u003c/p\u003e \u003cp\u003e(6.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e89\u003c/p\u003e \u003cp\u003e(7.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.248\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e48\u003c/p\u003e \u003cp\u003e(6.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e51\u003c/p\u003e \u003cp\u003e(6.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.740\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Disscussion","content":"\u003cp\u003eTo our knowledge, this study is the first to focus on the impact of prenatal inactivated COVID-19 vaccination on maternal and neonatal outcomes. During the study period, 42.9% of women who delivered between 2022.01.01 and 2022.06.30 included in the study received at least one dose of vaccine before delivery. Women in the vaccinated group had a higher number of previous deliveries, a higher percentage of scarred uteruses, and a significantly lower percentage of fertility treatments. Because of these underlying imbalances, we performed multivariate regression analysis and PSM to control the confounding factors that might affect the results. In this study, we found no significant association between vaccination and severe adverse pregnancy outcomes or neonatal complications. Although we found a slightly smaller gestational week of delivery and a possible increased rate of late preterm birth in the vaccination group, there was no difference in mean neonatal weight, incidence of low birth weight infants and other neonatal adverse complications.\u003c/p\u003e \u003cp\u003eStudies show that maternal and fetal outcomes worsened globally during the COVID-19 pandemic, with increases in maternal deaths, stillbirths, ruptured ectopic pregnancies, and maternal depression[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. A meta-analysis revealed that pregnant women with SARS-CoV-2 infection were at higher risk of preterm delivery, requiring mechanical ventilation, admission to an intensive care unit and death compared to non-pregnant women[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. As worsening symptoms of maternal infection may lead to more adverse neonatal outcomes. A cohort study involving 43 institutions in 18 countries found that comparing pregnant women with confirmed and undiagnosed COVID-19 identified that COVID-19 during pregnancy was associated with a substantial and sustained increase in severe maternal morbidity and mortality and neonatal complications. In addition, COVID-19 during pregnancy was associated with an increased risk of pregnancy-specific complications of pre-eclampsia, preterm delivery, and stillbirth[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Based on the special effects of SARS-CoV-2 infection on maternal and neonatal outcomes, most studies support the safety and protection of COVID-19 vaccine in pregnant women and their newborns[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e],\u003c/p\u003e \u003cp\u003eHowever, the problem is that there is still a lack of evidence on the safety of vaccination and its effects on maternal and neonatal outcomes. A meta-analysis evaluating evidence from 23 studies, including 117,552 pregnant women who received COVID-19 vaccine, showed that the effectiveness of mRNA vaccination was 89.5%. In the vaccinated cohort, the risk of stillbirth was significantly reduced by 15%[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Another study showed no differences in prenatal COVID-19 vaccination in terms of pregnancy, delivery, and neonatal complications, including gestational age at delivery, incidence of small for gestational age, and neonatal respiratory complications[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. It has been reported that vaccination with covid-19 during pregnancy was not associated with a higher risk of preterm delivery, younger gestational age at birth, or risk of stillbirth[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. A multicenter retrospective study showed that covid19 vaccination was not associated with maternal composite adverse outcomes and a significantly lower risk of neonatal composite adverse outcomes was observed[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, almost all of these above studies and evidence are based on mRNA vaccination.\u003c/p\u003e \u003cp\u003eIn China, COVID-19 inactivated vaccine (coronavirus vaccine) is the main type of COVID-19 vaccine available. Studies have shown that COVID-19 inactivated vaccine (coronavirus vaccine) is effective in preventing the transmission of COVID-19, with an efficiency of 65.9% in preventing COVID-19 infection, 87.5% in avoiding hospitalization, 90.3% in preventing ICU hospitalization, and 86.3% in preventing COVID-19 death[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Prospective cohort studies have shown that treatment of adults with either of the two inactivated SARS-CoV-2 vaccines significantly reduces the risk of symptomatic COVID-19 with few serious adverse events[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. However, there are no clinical data to determine whether inactivated vaccination of pregnant women may affect on maternal and neonatal outcomes or not. An animal study showed that human angiotensin-converting enzyme 2 (hACE2) mice vaccinated with inactivated COVID-19 vaccine before and during pregnancy exhibited normal body weight changes and reproductive performance indicators, and the physical development of their offspring was normal. Moreover, after intranasal vaccination with SARS-CoV-2, all pregnant mice in the immunized group survived, and the reproductive performance and physical development of their offspring were normal. In contrast, all mice in the non-immunized group died before delivery. This experiment may recommend that inactivated COVID-19 vaccination is safe and may effectively protects pregnant mice from SARS-CoV2 infection and has no adverse effects on offspring[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Huang etal. demonstrates that female vaccination with inactivated COVID-19 vaccine does not have any measurable deleterious effects on in vitro fertilization treatment and has no significant impact on embryonic laboratory parameters or pregnancy outcomes[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Another study on the prognosis of inactivated COVID-19 vaccine in frozen-thawed embryos for transfer revealed that live birth rates, sustained pregnancy rates and clinical pregnancy rates in vaccinated women were comparable to those in unvaccinated women, and birth length and birth weight were similar in both groups[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. However, none of these studies reported maternal-related complications, and only birth weight was analyzed regarding neonatal outcomes.\u003c/p\u003e \u003cp\u003eThis study is the first to focus on the effects of prenatal inactivated COVID-19 vaccination on maternal and neonatal outcomes and to analyze the relevant outcomes in detail, with results largely similar to those of similar studies described above. However, it is worth noting that we found an increased risk of overall preterm birth in the vaccinated group compared to unvaccinated women (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05), and it is important to mention that there was no difference in early preterm birth (\u0026lt;\u0026thinsp;32 weeks) rate and incidence of preterm birth\u0026thinsp;\u0026lt;\u0026thinsp;34 weeks, most preterm births were late preterm and there was no difference in neonatal outcomes. Although some studies have shown that vaccination does not increase the risk of preterm birth[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The study by Aharon Dick et al. had a similar outcome to ours, although their study population was vaccinated with mRNA vaccine. They included a larger sample and explored the association between risk of preterm birth and vaccination in early, midterm and late pregnancy separately. They found a higher risk of preterm delivery in those who were vaccinated in the midterm of pregnancy (8.1% vs. 6.2%).We therefore hypothesized that unmeasured confounding factors associated with vaccination may have contributed to the results[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eA large sample size was included in our study, although this was a retrospective study, detailed and accurate vaccination information, including vaccine manufacturer, dosing date, and fertility treatment information were available with the help of an electronic health database to ensure the reliability and authenticity of the retrospective results. However, two limitations of the study should also be noted. First, due to the single-center retrospective nature of the study, some baseline clinical characteristics may not have been adequately balanced. Second, due to the limited sample size, we were unable to match by time of the first vaccination. In addition, early pregnancy outcomes such as miscarriage and ectopic pregnancy cannot be studied.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn this cohort study, the inactivated COVID-19 vaccine appeared to be safe, and although there was an increased incidence of late preterm delivery compared with unvaccinated women, there was no significant increase in other adverse maternal and neonatal outcomes. Future studies that focus on outcomes at the time of vaccination may provide better understanding and more accurate counseling of patients regarding the risks and benefits of vaccination before and during pregnancy.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHadassah\u0026rsquo;s Helsinki committee fle no. HMO-21-0342 approved a waiver of \u0026nbsp;informed consent by participants due to the retrospective nature of the study and anonymization of personal information. All methods were performed in accordance with the relevant guidelines and regulations of the institutional ethical review board and in accordance with the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003eThe study was approved by the independent Ethics Committee of the First Affiliated Hospital of Wenzhou Medical University (fle no: KY2023-R038) .\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 Material (ADM)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data presented in these studies are available on request from the corresponding author.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization, Y.C.; methodology, Y.C. and W.X.; formal analysis, S.Z., F.X. and L.G.; data curation, X.X., S.W.,Y.C. and W.X.; writing\u0026mdash;original draft preparation, Y.C. and W.X.; writing\u0026mdash;review and editing, Y.C. , S.W and W.X.; supervision and project administration, W.X. All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eWORLD HEALTH ORGANIZATION. WHO Coronavirus（COVID-19） Dashboard［EB/OL］. https://covid19.who.int/. Accessed 30 Jan 2023.\u003c/li\u003e\n\u003cli\u003eDelahoy MJ, Whitaker M, O\u0026apos;Halloran A, Chai SJ, Kirley PD, Alden N, et al. Characteristics and Maternal and Birth Outcomes of Hospitalized Pregnant Women with Laboratory-Confirmed COVID-19 - COVID-NET, 13 States, March 1-August 22, 2020. MMWR Morb Mortal Wkly Rep. 2020;69(38):1347-54.\u003c/li\u003e\n\u003cli\u003eMcClymont E, Albert AY, Alton GD, Boucoiran I, Castillo E, Fell DB, et al. Association of SARS-CoV-2 Infection During Pregnancy With Maternal and Perinatal Outcomes. JAMA. 2022;327(20):1983-91.\u003c/li\u003e\n\u003cli\u003ePrasad S, Kalafat E, Blakeway H, Townsend R, O\u0026apos;Brien P, Morris E, et al. Systematic review and meta-analysis of the effectiveness and perinatal outcomes of COVID-19 vaccination in pregnancy. Nat Commun. 2022;13(1):2414.\u003c/li\u003e\n\u003cli\u003eRottenstreich M, Sela HY, Rotem R, Kadish E, Wiener-Well Y, Grisaru-Granovsky S. Covid-19 vaccination during the third trimester of pregnancy: rate of vaccination and maternal and neonatal outcomes, a multicentre retrospective cohort study. BJOG. 2022;129(2):248-55.\u003c/li\u003e\n\u003cli\u003eGoldshtein I, Steinberg DM, Kuint J, Chodick G, Segal Y, Shapiro Ben David S, et al. Association of BNT162b2 COVID-19 Vaccination During Pregnancy With Neonatal and Early Infant Outcomes. JAMA Pediatr. 2022;176(5):470-7.\u003c/li\u003e\n\u003cli\u003eWu Y, Ying Y, Cao M, Liu J, Liu H. Trophectoderm biopsy of blastocysts for a preimplantation genetic test does not affect serum beta-hCG levels in early pregnancy: a study using propensity score matching. J Ovarian Res. 2021;14(1):78.\u003c/li\u003e\n\u003cli\u003eChmielewska B, Barratt I, Townsend R, Kalafat E, van der Meulen J, Gurol-Urganci I, et al. Effects of the COVID-19 pandemic on maternal and perinatal outcomes: a systematic review and meta-analysis. Lancet Glob Health. 2021;9(6):e759-e72.\u003c/li\u003e\n\u003cli\u003eAllotey J, Stallings E, Bonet M, Yap M, Chatterjee S, Kew T, et al. Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis. BMJ. 2020;370:m3320.\u003c/li\u003e\n\u003cli\u003eVillar J, Ariff S, Gunier RB, Thiruvengadam R, Rauch S, Kholin A, et al. Maternal and Neonatal Morbidity and Mortality Among Pregnant Women With and Without COVID-19 Infection: The INTERCOVID Multinational Cohort Study. JAMA Pediatr. 2021;175(8):817-26.\u003c/li\u003e\n\u003cli\u003eRawal S, Tackett RL, Stone RH, Young HN. COVID-19 vaccination among pregnant people in the United States: a systematic review. Am J Obstet Gynecol MFM. 2022;4(4):100616.\u003c/li\u003e\n\u003cli\u003eWainstock T, Yoles I, Sergienko R, Sheiner E. Prenatal maternal COVID-19 vaccination and pregnancy outcomes. Vaccine. 2021;39(41):6037-40.\u003c/li\u003e\n\u003cli\u003eFell DB, Dimanlig-Cruz S, Regan AK, Haberg SE, Gravel CA, Oakley L, et al. Risk of preterm birth, small for gestational age at birth, and stillbirth after covid-19 vaccination during pregnancy: population based retrospective cohort study. BMJ. 2022;378:e071416.\u003c/li\u003e\n\u003cli\u003eJara A, Undurraga EA, Gonzalez C, Paredes F, Fontecilla T, Jara G, et al. Effectiveness of an Inactivated SARS-CoV-2 Vaccine in Chile. N Engl J Med. 2021;385(10):875-84.\u003c/li\u003e\n\u003cli\u003eAl Kaabi N, Zhang Y, Xia S, Yang Y, Al Qahtani MM, Abdulrazzaq N, et al. Effect of 2 Inactivated SARS-CoV-2 Vaccines on Symptomatic COVID-19 Infection in Adults: A Randomized Clinical Trial. JAMA. 2021;326(1):35-45.\u003c/li\u003e\n\u003cli\u003eLin K, Liu M, Bao L, Lv Q, Zhu H, Li D, et al. Safety and protective capability of an inactivated SARS-CoV-2 vaccine on pregnancy, lactation and the growth of offspring in hACE2 mice. Vaccine. 2022;40(32):4609-16.\u003c/li\u003e\n\u003cli\u003eHuang J, Xia L, Lin J, Liu B, Zhao Y, Xin C, et al. No Effect of Inactivated SARS-CoV-2 Vaccination on in vitro Fertilization Outcomes: A Propensity Score-Matched Study. J Inflamm Res. 2022;15:839-49.\u003c/li\u003e\n\u003cli\u003eCao M, Wu Y, Lin Y, Xu Z, Liang Z, Huang Q, et al. Inactivated Covid-19 vaccine did not undermine live birth and neonatal outcomes of women with frozen-thawed embryo transfer. Hum Reprod. 2022;37(12):2942-51.\u003c/li\u003e\n\u003cli\u003eDick A, Rosenbloom JI, Gutman-Ido E, Lessans N, Cahen-Peretz A, Chill HH. Safety of SARS-CoV-2 vaccination during pregnancy- obstetric outcomes from a large cohort study. BMC Pregnancy Childbirth. 2022;22(1):166.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"COVID-19, Inactivated vaccine, Maternal outcomes, Pregnancy, Neonatal outcomes","lastPublishedDoi":"10.21203/rs.3.rs-2710503/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2710503/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eThere are very few data on the maternal and neonatal safety effects of inactivated COVID-19 vaccines. Several studies have reported the safety of SARS-CoV-2 vaccination during pregnancy, with no adverse effect on maternal and neonatal outcomes. However, data on the safety of prenatal vaccination are scarce. Therefore, more relevant data are needed to inform maternal, pregnancy, and infant outcomes.\u003c/p\u003e\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eTo evaluate the prenatal maternal inactivated COVID-19 vaccination and the impact on maternal and neonatal outcomes.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA retrospective cohort study among women who delivered between January and June 2022 at the first affiliated hospital of wenzhou medical university. Those who have completed at least one dose of inactivated vaccine before or during pregnancy were included in \u0026ldquo;vaccinated group\u0026rdquo;, and those who were not vaccinated were included in \u0026ldquo;unvaccinated group\u0026rdquo;, the maternal, pregnancy and neonatal outcomes were evaluated. Propensity score matching (PSM) was performed to balance the baseline parameters of the two groups.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eA total of 1926 women were enrolled in this study, 827 (42.94%) women were prenatally vaccinated, and 1099 (57.06%) unvaccinated. The gestational week of delivery were slightly smaller in the vaccinated group, 38.77\u0026thinsp;\u0026plusmn;\u0026thinsp;1.83 weeks in the vaccinated group and 39.01\u0026thinsp;\u0026plusmn;\u0026thinsp;1.45 weeks in the unvaccinated group. There was a higher rate of overall preterm delivery in the vaccinated group (aOR 1.638, 95% CI 1.108\u0026ndash;2.422; p\u0026thinsp;=\u0026thinsp;0.013; Table\u0026nbsp;3, Fig.\u0026nbsp;2), however, the probability of delivery before 34 weeks and before 32 weeks (early preterm delivery) were similar (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). A total of 2009 infants were born, 851 in the vaccinated group and 1158 in the unvaccinated group. There were similar neonatal outcomes in the two groups.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eAlthough we found a slightly smaller gestational week of delivery and a possible increased rate of late preterm birth in the vaccination group, there was no difference in mean neonatal weight, incidence of low birth weight infants and other neonatal adverse complications. Meanwhile, there was no difference in pregnancy and maternal outcomes between the two groups.\u003c/p\u003e","manuscriptTitle":"Prenatal maternal inactivated COVID-19 vaccination: the maternal and neonatal outcomes, a retrospective cohort study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-04-10 17:39:49","doi":"10.21203/rs.3.rs-2710503/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"1c06b618-e629-4c08-b1a9-311a513246d9","owner":[],"postedDate":"April 10th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2023-09-17T08:29:13+00:00","versionOfRecord":[],"versionCreatedAt":"2023-04-10 17:39:49","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-2710503","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2710503","identity":"rs-2710503","version":["v1"]},"buildId":"_2-kVJe1T_tPrBINL-cwx","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}