Elective cesarean section at early term versus 39 weeks or beyond: impact on neonatal respiratory outcomes and maternal morbidities in a tertiary hospital: a retrospective cohort study

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This study compared maternal morbidity and neonatal respiratory outcomes between early-term (< 39 weeks) and full-term (≥ 39 weeks) ECS. Methods A retrospective cohort study was conducted at a tertiary care hospital from January 2022 to December 2024. Women undergoing scheduled ECS were categorized as early-term (< 39 weeks; n = 1,326) or full-term (≥ 39 weeks; n = 473). Maternal characteristics, operative outcomes, and neonatal respiratory morbidity were analyzed using Chi-square and Wilcoxon rank-sum test. Multivariable logistic regression identified factors independently associated with composite neonatal respiratory morbidity. Results Of 13,745 deliveries, 5,188 (37.7%) were cesarean sections, including 1,799 eligible ECS cases (1,326 early-term and 473 full-term). The main ECS indication was the previous cesarean section (73.9%). Early-term ECS was associated with lower neonatal birth weight and a higher proportion of twin pregnancies. No significant differences were observed in operative outcomes, Apgar scores, or crude neonatal respiratory morbidity. After adjustment for maternal and neonatal factors, early-term ECS was not independently associated with composite respiratory morbidity (adjusted OR 0.77, 95% CI 0.56–1.07). Maternal obesity (adjusted OR 1.40, 95% CI 1.04–1.87), male sex (adjusted OR 1.94, 95% CI 1.44–2.61), and low birth weight < 2,500 g (adjusted OR 3.28, 95% CI 1.85–5.80) were independently associated with increased odds of respiratory morbidity. Conclusions Early-term ECS was not independently associated with neonatal respiratory morbidity. Neonatal characteristics and maternal obesity were stronger predictors than gestational age alone, suggesting individualized, risk-based decision-making for ECS timing. Elective cesarean section Gestational age Maternal morbidity Neonatal respiratory complication Figures Figure 1 Introduction The global rate of cesarean section (CS) has increased substantially over recent decades, with projections estimating a rise from 21.1% in 2010–2018 to 28.5% by 2030 [ 1 ]. In Thailand, a study conducted at two tertiary hospitals in Bangkok during 2017–2018 reported an overall CS rate of 45%, with previous cesarean delivery (Robson Group 5) as the leading indication, accounting for 14% of all births [ 2 ]. This pattern reflects a growing proportion of women undergoing repeat cesarean sections, particularly in tertiary care settings where planned surgical births are common. Consequently, determining the optimal timing of elective cesarean section (ECS) is essential to balance maternal risks associated with spontaneous labor or emergency surgery against neonatal risks related to early delivery. Scheduling ECS before 39 weeks of gestation may reduce the likelihood of labor onset and related maternal complications [ 3 ]. However, multiple studies have demonstrated that early-term neonates (< 39 weeks) face significantly higher risks of respiratory morbidity, metabolic disturbances, and neonatal intensive care unit admission compared with those delivered at 39 weeks or later [ 4 ]. Current professional guidelines therefore recommend scheduling ECS between 39 + 0 and 39 + 6 weeks to minimize neonatal morbidity while maintaining maternal safety [ 5 – 9 ]. Despite these recommendations, ECS is frequently performed earlier due to obstetric indications or logistical constraints. Clinical challenges remain, as approximately 10–15% of women scheduled for ECS at 39 weeks enter labor before the planned date, resulting in unplanned or emergency cesarean deliveries associated with slightly higher maternal morbidity than elective procedures [ 8 – 10 ]. In selected high-risk situations—such as a history of uterine rupture, residence in remote areas, or significant logistical limitations—individualized scheduling between 38 and 39 weeks may be justified to avoid unplanned surgery [ 3 , 9 , 11 ]. Large multicenter studies, including those from the NICHD Maternal–Fetal Medicine Units Network, consistently show increased neonatal respiratory and metabolic morbidity when ECS is performed before 39 completed weeks without clear maternal benefit, supporting the “39-week rule” [ 4 , 10 , 12 – 14 ]. Nevertheless, evidence from some well-resourced tertiary centers suggests that carefully selected early-term ECS may not substantially increase neonatal morbidity [ 15 – 17 ]. Therefore, this study aimed to compare maternal and neonatal outcomes of ECS performed before and after 39 weeks of gestation in a tertiary care setting. Method Study design and population This retrospective cohort study was conducted at a tertiary care hospital from January 2022 to December 2024. All women undergoing ECS during the study period were screened for eligibility. ECS was defined as a planned cesarean delivery performed prior to the onset of labor. Eligible participants included women with planned cesarean delivery before labor, singleton or twin pregnancies, and gestational age ≥37 weeks, determined by first-trimester ultrasonography or a reliable last menstrual period. Women undergoing emergency cesarean section, pregnancies complicated by major fetal anomalies, and cases with incomplete clinical data were excluded. As a tertiary referral center, the actual date of ECS occasionally varied by 2–3 days from the originally scheduled date due to clinical or logistical considerations. Participants were classified according to gestational age at delivery into early-term (<39 weeks; n = 1,326) and full-term (≥39 weeks; n = 473) groups. Data collection and variables Maternal data included demographic characteristics, pregnancy-related risk factors, indications for ECS, and intraoperative outcomes. Neonatal data were analyzed on a per-infant basis and included sex, birth weight, Apgar scores, and neonatal complications. Neonatal complications assessed in this study comprised transient tachypnea of the newborn (TTNB), respiratory distress syndrome (RDS), neonatal jaundice, sepsis, and hypoglycemia. Outcomes The primary outcome was composite early neonatal respiratory morbidity, defined as the presence of at least one respiratory diagnosis per infant, identified using the International Classification of Diseases, 10th Revision (ICD-10) codes P220 (respiratory distress syndrome of the newborn), P221 (transient tachypnea of the newborn), P229 (respiratory distress of the newborn, unspecified), or P240 (neonatal aspiration syndrome), as detailed in Supplementary Table S1. Secondary outcomes included maternal operative and postpartum complications. Statistical analysis Statistical analyses were performed using R software (version 4.5.1). Continuous variables were summarized as medians with interquartile ranges (IQR) and compared using the Wilcoxon rank-sum test. Categorical variables were presented as frequencies and percentages and compared using the Chi-square test or Fisher’s exact test, as appropriate. Multivariable logistic regression analysis was conducted to identify factors independently associated with composite respiratory morbidity. Covariates included clinically relevant maternal and neonatal factors, including gestational age group, maternal age, body mass index, gestational diabetes, hypertensive disorders of pregnancy, neonatal sex, birth weight, and Pregnancy type. Adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were reported. A p-value <0.05 was considered statistically significant. Results Study population During the study period, 13,745 deliveries were recorded as illustrated in Figure 1, of which 5,188 (37.7%) were cesarean deliveries, including 3,288 (63.4%) emergency and 1,900 (36.6%) elective procedures. After excluding cases with gestational age <37 weeks (n = 50) and incomplete clinical data (n = 51), a total of 1,799 women undergoing ECS were included in the final analysis. Of these, 1,326 women (73.7%) delivered at early term (<39 weeks), while 473 (26.3%) delivered at full term (≥39 weeks). Neonatal outcomes were assessed per infant, comprising 1,837 neonates, including 76 twins. Maternal characteristics Maternal characteristics stratified by gestational age at ECS are presented in Table 1. Women who underwent early-term ECS were slightly older than those who delivered at full term (median age 31 vs. 30 years, p = 0.045). Gravida and parity were also significantly higher in the early-term group ( p = 0.004 and p = 0.001, respectively). There were no significant differences between groups in pre-pregnancy body mass index, hypertensive disorders, diabetes, or placenta previa. However, a history of prior cesarean section was significantly more common among women undergoing early-term ECS (78.4% vs. 61.0%, p < 0.001). Breech presentation and large fetus were also more frequently observed in the full-term ECS group ( p = 0.028 and p < 0.001, respectively). Table 1. Maternal characteristics by gestational age at elective cesarean section Characteristics All (n=1,799) GA <39 wks (n=1,326) GA ≥ 39 wks (n= 473) p-value Maternal age (years), median (IQR) 31 (27-35) 31 (27-35) 30 (26-34) 0.045 Pre-pregnancy BMI (kg/m²), median (IQR) 29.3 (26.1-33.3) 29.4 (26.2-33.4) 29.1 (26.0-33.2) 0.550 Gravida, median (IQR) 2 (2-3) 2 (2-3) 2 (2-3) 0.004 Parity, median (IQR) 1 (1-2) 1 (1-2) 1 (1-2) 0.001 Hypertensive disorders, n (%) 124 (6.9) 99 (7.5) 25 (5.3) 0.120 Diabetes, n (%) 216 (12.0) 160 (12.0) 56 (11.8) 0.902 Prior cesarean section, n (%) 1,329 (73.9) 1,039 (78.4) 290 (61.0) <0.001 Breech presentation, n (%) 196 (10.9) 132 (10.0) 64 (13.5) 0.028 Large fetus, n (%) 100 (5.6) 40 (3.0) 60 (12.7) <0.001 Placenta previa, n (%) 33 (1.8) 26 (2.0) 7 (1.5) 0.507 Values are presented as median IQR(interquartile range) or number (%) Abbreviations: GA, gestational age; BMI, body mass index; kg/(m)2=kilogram per square metre Operative and maternal outcomes Operative and maternal outcomes are summarized in Table 2. Median hematocrit levels, operative time, and estimated blood loss were comparable between the early-term and full-term groups. The incidence of postpartum hemorrhage and blood transfusion did not differ significantly between groups, indicating no significant differences in short-term maternal operative outcomes according to gestational age at ECS. Table 2. Operative and maternal outcomes by gestational age Outcomes All (n=1,799) GA <39 wks (n=1,326) GA ≥ 39 wks (n= 473) p-value Hematocrit (%), median (IQR) 35 (33–38) 35 (33–38) 35 (33–37) 0.12 Operative time (min), median (IQR) 45 (40–55) 45 (40–55) 45 (35–55) 0.20 Estimated blood loss (mL), median (IQR) 500 (400–600) 500 (400–600) 500 (400–600) 0.257 Postpartum hemorrhage, n (%) 6 (0.3) 4 (0.3) 2 (0.4) 0.681 Blood transfusion, n (%) 88 (4.9) 73 (5.5) 15 (3.2) 0.124 Values are presented as median IQR(interquartile range) or number (%) Abbreviations: GA, gestational age; min=minute; mL = milliliter Neonatal characteristics Neonatal characteristics are shown in Table 3. Multiple gestation was significantly more frequent in the early-term group compared with the full-term group (5.3% vs. 0.8%, p = 0.001). Infants delivered at early term had a significantly lower birth weight than those delivered at full term (median 3,105 g vs. 3,243 g, p < 0.001). Apgar scores at 1 and 5 minutes were high and comparable between groups. Neonatal respiratory outcomes Neonatal respiratory outcomes are presented in Table 4. The overall incidence of composite respiratory morbidity was 11.9% (218/1,837). There was no significant difference in composite respiratory morbidity between infants delivered at early term and those delivered at full term (11.5% vs. 13.1%, p = 0.354). Table 3. Neonatal characteristics (per infant analysis) Characteristics All (n=1,837) GA <39 wks (n=1,362) GA ≥ 39 wks (n= 475) p-value Pregnancy type, n (%) 0.001 Singleton 1,761 (95.9) 1,290 (94.7) 471 (99.2) Twin 76 (4.1) 72 (5.3) 4 (0.8) Male sex, n (%) 923 (50.2) 689 (50.6) 234 (49.3) 0.619 Birth weight (g), median (IQR) 3,135 (2,875-3,400) 3,105 (2,850-3,340) 3,243 (2,970-3,535) <0.001 Apgar score at 1 min, median (IQR) 9 (9-9) 9 (9-9) 9 (9-9) 0.670 Apgar score at 5 min, median (IQR) 9 (9-9) 9 (9-9) 9 (9-9) 0.945 Values are presented as median IQR(interquartile range) or number (%) Abbreviations: GA, gestational age; min=minute; g = gram Factors associated with composite respiratory morbidity Results of crude and multivariable logistic regression analyses are shown in Table 5. In crude analysis, maternal obesity (BMI ≥30 kg/m²), male sex, low birth weight (<2,500 g), and twin pregnancy were significantly associated with composite respiratory morbidity. Early-term ECS before 39 weeks was not significantly associated with respiratory morbidity in the crude model (OR 0.86, 95% CI 0.63–1.18; p = 0.354). Table 4. Neonatal outcomes with composite respiratory morbidity Neonatal outcomes Total GA <39 wks (n=1,362) GA ≥ 39 wks (n= 475) p-value Composite respiratory morbidity* 218 (11.9) 156 (11.5) 62 (13.1) 0.354 * Composite respiratory morbidity was defined as the presence of at least one respiratory diagnosis per infant, identified using ICD-10 codes P220, P221, P229, or P240. Abbreviations: GA, gestational age After adjustment for maternal and neonatal factors, including maternal age, body mass index, gestational diabetes, hypertensive disorders of pregnancy, neonatal sex, birth weight, and pregnancy type, early-term ECS was not independently associated with composite respiratory morbidity (adjusted OR 0.77, 95% CI 0.56–1.07; p = 0.122). Maternal obesity remained independently associated with an increased risk of composite respiratory morbidity (adjusted OR 1.40, 95% CI 1.04–1.87; p = 0.026). Neonatal factors demonstrated the strongest associations: male sex (adjusted OR 1.94, 95% CI 1.44–2.61; p < 0.001) and low birth weight (<2,500 g) (adjusted OR 3.28, 95% CI 1.85–5.80; p < 0.001) were independently associated with increased odds of composite respiratory morbidity. Twin pregnancy and gestational diabetes were not independently associated with respiratory morbidity after multivariable adjustment. Table 5 Multivariable Logistic Regression Analysis of Factors Associated with Composite Respiratory Morbidity Variable Crude OR (95%CI) p-value Adjusted OR (95%CI) p-value Early-term ECS (<39 weeks) 0.86 (0.63,1.18) 0.354 0.77 (0.56,1.07) 0.122 Maternal age ≥35 years 1.06 (0.77,1.45) 0.738 1.07 (0.77,1.49) 0.672 BMI ≥30 kg/(m)² 1.37 (1.03,1.82) 0.029 1.4 (1.04,1.87) 0.026 Gestational diabetes 1.2 (0.77,1.87) 0.414 1.05 (0.66,1.66) 0.830 Hypertensive disorders 1.34 (0.8,2.22) 0.265 1.11 (0.65,1.9) 0.709 Male 1.87 (1.4,2.51) <0.001 1.94 (1.44,2.61) <0.001 Birth weight <2500 g 3.04 (1.84,5.02) <0.001 3.28 (1.85,5.8) <0.001 Twin 1.89 (1.05,3.38) 0.033 1.26 (0.64,2.48) 0.502 Abbreviations: CI, confidence interval; ECS, elective cesarean section; BMI, body mass index; kg/(m)2=kilogram per square metre; g = gram Discussion This study found no significant differences in neonatal or maternal morbidity between early-term and full-term ECS. After adjustment for relevant maternal and neonatal factors, early-term ECS was not independently associated with composite respiratory morbidity. Although early-term infants had lower birth weights and higher rates of twin pregnancies, this did not translate into increased respiratory or metabolic complications. These findings suggest that previously reported associations between early-term ECS and neonatal respiratory morbidity may reflect confounding by underlying maternal and neonatal characteristics rather than the effect of gestational age alone. When clinically indicated and performed in well-prepared settings, early-term ECS appears to be safe, consistent with evidence from high-resource environments where advanced neonatal care mitigates risks traditionally linked to earlier delivery [17–20]. Prior studies have reported increased neonatal respiratory morbidity with early-term delivery, with risk decreasing as gestational age approaches or exceeds 38 weeks [12–13,21–23]. Immaturity of lung fluid clearance mechanisms and reduced catecholamine surges have been proposed as underlying mechanisms [24]. The absence of significant respiratory differences in the present study may reflect careful case selection and improvements in perioperative and neonatal management. Similar to findings by Tita et al. and Thai multicenter cohorts [12,22], Al Bizri et al. reported declining respiratory morbidity and NICU admissions with advancing gestational age, without differences in mortality or Apgar scores [25]. Maternal outcomes were comparable between early-term and full-term ECS, consistent with findings from Limrungsikul et al. and Phaloprakarn et al. [22–23]. Together, these data support the maternal safety of early-term ECS in well-resourced settings, while reinforcing existing recommendations to schedule elective cesarean delivery at or beyond 39 weeks to minimize preventable neonatal risk. Maternal obesity emerged as an independent predictor of neonatal respiratory morbidity, with elevated risks of respiratory distress syndrome, transient tachypnea of the newborn, and bronchopulmonary dysplasia among infants of mothers with higher pre-pregnancy BMI [26]. Altered intrauterine metabolic and inflammatory environments may adversely affect fetal lung development, increasing vulnerability to respiratory complications [27], underscoring the importance of optimizing maternal health before and during pregnancy. Differences in clinical characteristics reflected scheduling considerations: prior cesarean delivery was more common in early-term ECS, whereas breech presentation and large-for-gestational-age fetuses predominated at ≥39 weeks. Delaying ECS increases the likelihood of spontaneous labor and unplanned surgery, particularly in women with previous uterine scars, and emergency cesarean delivery carries higher risks of hemorrhage, infection, and anesthetic complications [10–11,17]. Phaloprakarn et al. reported that spontaneous labor occurred in 41.2% of women awaiting ECS, while scheduling at 40 weeks increased it [23]. Similarly, scheduling ECS at 39 weeks has been associated with higher rates of emergency cesarean delivery, maternal intraoperative complications, and neonatal NICU admission compared with delivery at 38 weeks [17]. Neonatal respiratory morbidity in this cohort was more strongly associated with intrinsic neonatal factors and maternal metabolic status than with ECS timing within the early-term period. Neonatal factors showed the strongest associations, with male sex conferring nearly twice the risk of respiratory distress syndrome, consistent with known sex-related differences in lung maturation and surfactant production [28]. Low birth weight was also a key predictor, with affected infants exhibiting substantially higher odds of respiratory morbidity, highlighting the importance of fetal growth and maturity [29]. Despite reassuring short-term outcomes, long-term data suggest potential developmental disadvantages associated with early-term birth. Boyle et al. reported increased risks of developmental, behavioral, and health problems among children born at 37–38 weeks compared with those born at 39–41 weeks [30], while Shirazi et al. observed impaired early growth and psychomotor development following ECS before 39 weeks [31]. Collectively, these findings support recommendations to avoid non-medically indicated cesarean delivery before 39 weeks to optimize neonatal growth, neurodevelopment, and overall outcomes [3,6,25]. Strengths and limitations This study is strengthened by its large sample size and comprehensive evaluation of maternal and neonatal outcomes. Limitations include its retrospective design, potential selection bias, and single-center setting may limit causal inference and generalizability. In addition, long-term neonatal outcomes were not evaluated. Future prospective multicenter studies are needed to confirm these findings across diverse clinical settings. While randomized trials are unlikely due to ethical constraints, large registry-based studies could help refine recommendations on the optimal timing of elective cesarean section and assess cost-effectiveness and long-term neurodevelopmental outcomes. Conclusion Early-term ECS was not independently associated with neonatal respiratory morbidity. Neonatal factors and maternal obesity were stronger determinants than gestational age alone, indicating that ECS timing should be guided by overall maternal–fetal risk profiles rather than gestational age in isolation. Abbreviations CS cesarean section ECS elective cesarean section NICU Neonatal Intensive Care Unit NICHD National Institute of Child Health and Human Development MFMU Maternal–Fetal Medicine Units Network TTNB transient tachypnea of the newborn RDS respiratory distress syndrome Declarations Ethics approval and consent to participate This study was reviewed and approved by the Research Ethics Committee of Hat Yai Hospital (Protocol Number HYH EC 099-67-01). The requirement for informed consent was waived, as the study utilized retrospective cohort data. Availability of data and materials The datasets generated and analyzed during the current study are available from the corresponding author upon reasonable request. Data sharing is subject to approval by the health service authority and the research ethics committee. Consent to publish declaration not applicable Competing interests The authors declare that they have no competing interests. Funding No external funding was received for this study. Authors’ contributions SS conceived and designed the study, performed data analysis and interpretation, and was the principal author of the manuscript. AB contributed to study design, obtained ethical approval and coordinated data collection. KK participated in data analysis and provided administrative and material support. All authors had full access to the study data, reviewed and approved the final manuscript, and accepted responsibility for the integrity and accuracy of the work. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8675318","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":586479576,"identity":"0c995f20-8529-4830-9f01-1d9ece79544e","order_by":0,"name":"Sunittha Sanguanchua","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0UlEQVRIiWNgGAWjYLCCBBBibwCyDCyI1ZJgkMDAcwCkRYJoa4BaJBJALCK0yPefMXvw8MefPP6Zz69u+FEgwcDf3p2AV4vBjRxzA6DDiiVu55Td7AE6TOLM2Q34tUjwmEkAtSQ23M5Ju8ED1GIgkYtfC8hhYC3zb55Ju/mHGC0MB3IgWjbcYD92myhbDG6klUkkpBknbjyTw3ZbBuhOgn6R7z+8TfKHjVzivOPHn91888dGjr+9l4DDEIDHAEwSqxwE2B+QonoUjIJRMApGEAAAuzFIWt1H9kwAAAAASUVORK5CYII=","orcid":"","institution":"Hatyai hospital","correspondingAuthor":true,"prefix":"","firstName":"Sunittha","middleName":"","lastName":"Sanguanchua","suffix":""},{"id":586479578,"identity":"b7d7d6b3-b5af-43aa-8f8f-fc2f6102d7fb","order_by":1,"name":"Arnat Benjalak","email":"","orcid":"","institution":"Hatyai hospital","correspondingAuthor":false,"prefix":"","firstName":"Arnat","middleName":"","lastName":"Benjalak","suffix":""},{"id":586479579,"identity":"06471ed9-c9e3-431d-b755-48ee5eef071f","order_by":2,"name":"Khodeeyoh Kasoh","email":"","orcid":"","institution":"Siriraj Hospital","correspondingAuthor":false,"prefix":"","firstName":"Khodeeyoh","middleName":"","lastName":"Kasoh","suffix":""}],"badges":[],"createdAt":"2026-01-23 05:38:48","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8675318/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8675318/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102212532,"identity":"160a7618-e482-476f-97ec-b1ac93f16230","added_by":"auto","created_at":"2026-02-09 12:34:11","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":74311,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart detailing to reach study sample\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8675318/v1/93a3bbc56ab9afc7813132a2.png"},{"id":102212558,"identity":"5ed5726c-eece-44d6-bb30-60cf2c4096d5","added_by":"auto","created_at":"2026-02-09 12:34:16","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":918398,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8675318/v1/24f14612-572d-4c85-bbfe-b11016d405e1.pdf"},{"id":102212533,"identity":"516dc1f8-1b71-4b3d-b8d3-1d21659e2444","added_by":"auto","created_at":"2026-02-09 12:34:11","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":15978,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryTables.docx","url":"https://assets-eu.researchsquare.com/files/rs-8675318/v1/1707b3145b7959743704fc67.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Elective cesarean section at early term versus 39 weeks or beyond: impact on neonatal respiratory outcomes and maternal morbidities in a tertiary hospital: a retrospective cohort study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe global rate of cesarean section (CS) has increased substantially over recent decades, with projections estimating a rise from 21.1% in 2010\u0026ndash;2018 to 28.5% by 2030 [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In Thailand, a study conducted at two tertiary hospitals in Bangkok during 2017\u0026ndash;2018 reported an overall CS rate of 45%, with previous cesarean delivery (Robson Group 5) as the leading indication, accounting for 14% of all births [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. This pattern reflects a growing proportion of women undergoing repeat cesarean sections, particularly in tertiary care settings where planned surgical births are common. Consequently, determining the optimal timing of elective cesarean section (ECS) is essential to balance maternal risks associated with spontaneous labor or emergency surgery against neonatal risks related to early delivery.\u003c/p\u003e \u003cp\u003eScheduling ECS before 39 weeks of gestation may reduce the likelihood of labor onset and related maternal complications [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. However, multiple studies have demonstrated that early-term neonates (\u0026lt;\u0026thinsp;39 weeks) face significantly higher risks of respiratory morbidity, metabolic disturbances, and neonatal intensive care unit admission compared with those delivered at 39 weeks or later [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Current professional guidelines therefore recommend scheduling ECS between 39\u0026thinsp;+\u0026thinsp;0 and 39\u0026thinsp;+\u0026thinsp;6 weeks to minimize neonatal morbidity while maintaining maternal safety [\u003cspan additionalcitationids=\"CR6 CR7 CR8\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Despite these recommendations, ECS is frequently performed earlier due to obstetric indications or logistical constraints.\u003c/p\u003e \u003cp\u003eClinical challenges remain, as approximately 10\u0026ndash;15% of women scheduled for ECS at 39 weeks enter labor before the planned date, resulting in unplanned or emergency cesarean deliveries associated with slightly higher maternal morbidity than elective procedures [\u003cspan additionalcitationids=\"CR9\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In selected high-risk situations\u0026mdash;such as a history of uterine rupture, residence in remote areas, or significant logistical limitations\u0026mdash;individualized scheduling between 38 and 39 weeks may be justified to avoid unplanned surgery [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Large multicenter studies, including those from the NICHD Maternal\u0026ndash;Fetal Medicine Units Network, consistently show increased neonatal respiratory and metabolic morbidity when ECS is performed before 39 completed weeks without clear maternal benefit, supporting the \u0026ldquo;39-week rule\u0026rdquo; [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Nevertheless, evidence from some well-resourced tertiary centers suggests that carefully selected early-term ECS may not substantially increase neonatal morbidity [\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Therefore, this study aimed to compare maternal and neonatal outcomes of ECS performed before and after 39 weeks of gestation in a tertiary care setting.\u003c/p\u003e"},{"header":"Method","content":"\u003cp\u003e\u003cstrong\u003eStudy design and population\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis retrospective cohort study was conducted at a tertiary care hospital from January 2022 to December 2024. All women undergoing ECS during the study period were screened for eligibility. ECS was defined as a planned cesarean delivery performed prior to the onset of labor.\u003c/p\u003e\n\u003cp\u003eEligible participants included women with planned cesarean delivery before labor, singleton or twin pregnancies, and gestational age \u0026ge;37 weeks, determined by first-trimester ultrasonography or a reliable last menstrual period. Women undergoing emergency cesarean section, pregnancies complicated by major fetal anomalies, and cases with incomplete clinical data were excluded.\u003c/p\u003e\n\u003cp\u003eAs a tertiary referral center, the actual date of ECS occasionally varied by 2\u0026ndash;3 days from the originally scheduled date due to clinical or logistical considerations. Participants were classified according to gestational age at delivery into early-term (\u0026lt;39 weeks; n = 1,326) and full-term (\u0026ge;39 weeks; n = 473) groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData collection and variables\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMaternal data included demographic characteristics, pregnancy-related risk factors, indications for ECS, and intraoperative outcomes. Neonatal data were analyzed on a per-infant basis and included sex, birth weight, Apgar scores, and neonatal complications.\u003c/p\u003e\n\u003cp\u003eNeonatal complications assessed in this study comprised transient tachypnea of the newborn (TTNB), respiratory distress syndrome (RDS), neonatal jaundice, sepsis, and hypoglycemia.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOutcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe primary outcome was composite early neonatal respiratory morbidity, defined as the presence of at least one respiratory diagnosis per infant, identified using the \u003cem\u003eInternational Classification of Diseases, 10th Revision (ICD-10)\u003c/em\u003e codes P220 (respiratory distress syndrome of the newborn), P221 (transient tachypnea of the newborn), P229 (respiratory distress of the newborn, unspecified), or P240 (neonatal aspiration syndrome), as detailed in Supplementary Table S1.\u003c/p\u003e\n\u003cp\u003eSecondary outcomes included maternal operative and postpartum complications.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStatistical analyses were performed using R software (version 4.5.1). Continuous variables were summarized as medians with interquartile ranges (IQR) and compared using the Wilcoxon rank-sum test. Categorical variables were presented as frequencies and percentages and compared using the Chi-square test or Fisher\u0026rsquo;s exact test, as appropriate.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMultivariable logistic regression analysis was conducted to identify factors independently associated with composite respiratory morbidity. Covariates included clinically relevant maternal and neonatal factors, including gestational age group, maternal age, body mass index, gestational diabetes, hypertensive disorders of pregnancy, neonatal sex, birth weight, and Pregnancy type. Adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were reported. A p-value \u0026lt;0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eStudy population\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDuring the study period, 13,745 deliveries were recorded as illustrated in Figure 1, of which 5,188 (37.7%) were cesarean deliveries, including 3,288 (63.4%) emergency and 1,900 (36.6%) elective procedures. After excluding cases with gestational age \u0026lt;37 weeks (n = 50) and incomplete clinical data (n = 51), a total of 1,799 women undergoing ECS were included in the final analysis.\u003c/p\u003e\n\u003cp\u003eOf these, 1,326 women (73.7%) delivered at early term (\u0026lt;39 weeks), while 473 (26.3%) delivered at full term (\u0026ge;39 weeks). Neonatal outcomes were assessed per infant, comprising 1,837 neonates, including 76 twins.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaternal characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMaternal characteristics stratified by gestational age at ECS are presented in Table 1. Women who underwent early-term ECS were slightly older than those who delivered at full term (median age 31 vs. 30 years, \u003cem\u003ep\u003c/em\u003e = 0.045). Gravida and parity were also significantly higher in the early-term group (\u003cem\u003ep\u003c/em\u003e = 0.004 and \u003cem\u003ep\u003c/em\u003e = 0.001, respectively).\u003c/p\u003e\n\u003cp\u003eThere were no significant differences between groups in pre-pregnancy body mass index, hypertensive disorders, diabetes, or placenta previa. However, a history of prior cesarean section was significantly more common among women undergoing early-term ECS (78.4% vs. 61.0%, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001). Breech presentation and large fetus were also more frequently observed in the full-term ECS group (\u003cem\u003ep\u003c/em\u003e = 0.028 and \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001, respectively).\u003c/p\u003e\n\u003cp\u003eTable 1. Maternal characteristics by gestational age at elective cesarean section\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"624\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 251px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCharacteristics\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAll (n=1,799)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGA \u0026lt;39 wks (n=1,326)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGA \u0026ge;\u003c/strong\u003e\u003cstrong\u003e39\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;wks (n=\u003c/strong\u003e\u003cstrong\u003e473)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 251px;\"\u003e\n \u003cp\u003eMaternal age (years), median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e31 (27-35)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e31 (27-35)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e30 (26-34)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.045\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 251px;\"\u003e\n \u003cp\u003ePre-pregnancy BMI (kg/m\u0026sup2;), median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e29.3 (26.1-33.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e29.4 (26.2-33.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e29.1 (26.0-33.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.550\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 251px;\"\u003e\n \u003cp\u003eGravida, median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e2 (2-3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e2 (2-3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e2 (2-3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.004\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 251px;\"\u003e\n \u003cp\u003eParity, median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e1 (1-2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e1 (1-2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e1 (1-2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 251px;\"\u003e\n \u003cp\u003eHypertensive disorders, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e124 (6.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e99 (7.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e25 (5.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.120\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 251px;\"\u003e\n \u003cp\u003eDiabetes, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e216 (12.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e160 (12.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e56 (11.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.902\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 251px;\"\u003e\n \u003cp\u003ePrior cesarean section, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e1,329 (73.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e1,039 (78.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e290 (61.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 251px;\"\u003e\n \u003cp\u003eBreech presentation, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e196 (10.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e132 (10.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e64 (13.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.028\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 251px;\"\u003e\n \u003cp\u003eLarge fetus, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e100 (5.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e40 (3.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e60 (12.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 251px;\"\u003e\n \u003cp\u003ePlacenta previa, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e33 (1.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e26 (2.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e7 (1.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.507\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eValues are presented as median IQR(interquartile range) or number (%)\u003c/p\u003e\n\u003cp\u003eAbbreviations: GA, gestational age;\u0026nbsp;BMI, body mass index;\u0026nbsp;kg/(m)2=kilogram per square metre\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOperative and maternal outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOperative and maternal outcomes are summarized in Table 2. Median hematocrit levels, operative time, and estimated blood loss were comparable between the early-term and full-term groups. The incidence of postpartum hemorrhage and blood transfusion did not differ significantly between groups, indicating no significant differences in short-term maternal operative outcomes according to gestational age at ECS.\u003c/p\u003e\n\u003cp\u003eTable 2. Operative and maternal outcomes by gestational age\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"624\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOutcomes\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAll (n=1,799)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGA \u0026lt;39 wks (n=1,326)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGA \u0026ge;\u003c/strong\u003e\u003cstrong\u003e39\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;wks (n=\u003c/strong\u003e\u003cstrong\u003e473)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eHematocrit (%), median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e35 (33\u0026ndash;38)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e35 (33\u0026ndash;38)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e35 (33\u0026ndash;37)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eOperative time (min), median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e45 (40\u0026ndash;55)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e45 (40\u0026ndash;55)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e45 (35\u0026ndash;55)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eEstimated blood loss (mL), median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e500 (400\u0026ndash;600)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e500 (400\u0026ndash;600)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e500 (400\u0026ndash;600)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.257\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003ePostpartum hemorrhage, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e6 (0.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e4 (0.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e2 (0.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.681\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eBlood transfusion, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e88 (4.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e73 (5.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e15 (3.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e0.124\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eValues are presented as median IQR(interquartile range) or number (%)\u003c/p\u003e\n\u003cp\u003eAbbreviations: GA, gestational age;\u0026nbsp;min=minute;\u0026nbsp;mL = milliliter\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNeonatal characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNeonatal characteristics are shown in Table 3. Multiple gestation was significantly more frequent in the early-term group compared with the full-term group (5.3% vs. 0.8%, \u003cem\u003ep\u003c/em\u003e = 0.001). Infants delivered at early term had a significantly lower birth weight than those delivered at full term (median 3,105 g vs. 3,243 g, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001). Apgar scores at 1 and 5 minutes were high and comparable between groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNeonatal respiratory outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNeonatal respiratory outcomes are presented in Table 4. The overall incidence of composite respiratory morbidity was 11.9% (218/1,837). There was no significant difference in composite respiratory morbidity between infants delivered at early term and those delivered at full term (11.5% vs. 13.1%, \u003cem\u003ep\u003c/em\u003e = 0.354).\u003c/p\u003e\n\u003cp\u003eTable 3. Neonatal characteristics (per infant analysis)\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"624\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCharacteristics\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAll (n=1,837)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGA \u0026lt;39 wks (n=1,362)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGA \u0026ge;\u003c/strong\u003e\u003cstrong\u003e39\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;wks (n=\u003c/strong\u003e\u003cstrong\u003e475)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003ePregnancy type, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eSingleton\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e1,761 (95.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e1,290 (94.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e471 (99.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eTwin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e76 (4.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e72 (5.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e4 (0.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eMale sex, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e923 (50.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e689 (50.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e234 (49.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e0.619\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eBirth weight (g), median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e3,135 (2,875-3,400)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e3,105 (2,850-3,340)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e3,243 (2,970-3,535)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eApgar score at 1 min, median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e9 (9-9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e9 (9-9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e9 (9-9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e0.670\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003eApgar score at 5 min, median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e9 (9-9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e9 (9-9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 121px;\"\u003e\n \u003cp\u003e9 (9-9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 55px;\"\u003e\n \u003cp\u003e0.945\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eValues are presented as median IQR(interquartile range) or number (%)\u003c/p\u003e\n\u003cp\u003eAbbreviations: GA, gestational age;\u0026nbsp;min=minute;\u0026nbsp;g = gram\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFactors associated with composite respiratory morbidity\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eResults of crude and multivariable logistic regression analyses are shown in Table 5. In crude analysis, maternal obesity (BMI \u0026ge;30 kg/m\u0026sup2;), male sex, low birth weight (\u0026lt;2,500 g), and twin pregnancy were significantly associated with composite respiratory morbidity. Early-term ECS before 39 weeks was not significantly associated with respiratory morbidity in the crude model (OR 0.86, 95% CI 0.63\u0026ndash;1.18; p = 0.354).\u003c/p\u003e\n\u003cp\u003eTable 4. Neonatal outcomes with composite respiratory morbidity\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"624\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 224px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNeonatal outcomes\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTotal\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGA \u0026lt;39 wks (n=1,362)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGA \u0026ge;\u003c/strong\u003e\u003cstrong\u003e39\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;wks (n=\u003c/strong\u003e\u003cstrong\u003e475)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 224px;\"\u003e\n \u003cp\u003eComposite respiratory morbidity*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 99px;\"\u003e\n \u003cp\u003e218 (11.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 114px;\"\u003e\n \u003cp\u003e156 (11.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e62 (13.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.354\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e* Composite respiratory morbidity was defined as the presence of at least one respiratory diagnosis per infant, identified using ICD-10 codes P220, P221, P229, or P240.\u003c/p\u003e\n\u003cp\u003eAbbreviations: GA, gestational age\u003c/p\u003e\n\u003cp\u003eAfter adjustment for maternal and neonatal factors, including maternal age, body mass index, gestational diabetes, hypertensive disorders of pregnancy, neonatal sex, birth weight, and pregnancy type, early-term ECS was not independently associated with composite respiratory morbidity (adjusted OR 0.77, 95% CI 0.56\u0026ndash;1.07; \u003cem\u003ep\u003c/em\u003e = 0.122).\u003c/p\u003e\n\u003cp\u003eMaternal obesity remained independently associated with an increased risk of composite respiratory morbidity (adjusted OR 1.40, 95% CI 1.04\u0026ndash;1.87; \u003cem\u003ep\u003c/em\u003e = 0.026). Neonatal factors demonstrated the strongest associations: male sex (adjusted OR 1.94, 95% CI 1.44\u0026ndash;2.61; \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001) and low birth weight (\u0026lt;2,500 g) (adjusted OR 3.28, 95% CI 1.85\u0026ndash;5.80; \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001) were independently associated with increased odds of composite respiratory morbidity. Twin pregnancy and gestational diabetes were not independently associated with respiratory morbidity after multivariable adjustment.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 5 Multivariable Logistic Regression Analysis of Factors Associated with Composite Respiratory Morbidity\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"624\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariable\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCrude OR (95%CI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 72px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAdjusted OR (95%CI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eEarly-term ECS (\u0026lt;39 weeks)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 138px;\"\u003e\n \u003cp\u003e0.86 (0.63,1.18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 72px;\"\u003e\n \u003cp\u003e0.354\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e0.77 (0.56,1.07)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.122\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eMaternal age \u0026ge;35\u0026nbsp;years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 138px;\"\u003e\n \u003cp\u003e1.06 (0.77,1.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 72px;\"\u003e\n \u003cp\u003e0.738\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 162px;\"\u003e\n \u003cp\u003e1.07 (0.77,1.49)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.672\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eBMI \u0026ge;30\u0026nbsp;kg/(m)\u0026sup2;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 138px;\"\u003e\n \u003cp\u003e1.37 (1.03,1.82)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 72px;\"\u003e\n \u003cp\u003e0.029\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 162px;\"\u003e\n \u003cp\u003e1.4 (1.04,1.87)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.026\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eGestational diabetes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 138px;\"\u003e\n \u003cp\u003e1.2 (0.77,1.87)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 72px;\"\u003e\n \u003cp\u003e0.414\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 162px;\"\u003e\n \u003cp\u003e1.05 (0.66,1.66)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.830\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eHypertensive disorders\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 138px;\"\u003e\n \u003cp\u003e1.34 (0.8,2.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 72px;\"\u003e\n \u003cp\u003e0.265\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 162px;\"\u003e\n \u003cp\u003e1.11 (0.65,1.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.709\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 138px;\"\u003e\n \u003cp\u003e1.87 (1.4,2.51)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 72px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 162px;\"\u003e\n \u003cp\u003e1.94 (1.44,2.61)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eBirth weight \u0026lt;2500 g\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 138px;\"\u003e\n \u003cp\u003e3.04 (1.84,5.02)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 72px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 162px;\"\u003e\n \u003cp\u003e3.28 (1.85,5.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eTwin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 138px;\"\u003e\n \u003cp\u003e1.89 (1.05,3.38)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 72px;\"\u003e\n \u003cp\u003e0.033\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 162px;\"\u003e\n \u003cp\u003e1.26 (0.64,2.48)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.502\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAbbreviations: CI, confidence interval; ECS, elective cesarean section; BMI, body mass index; kg/(m)2=kilogram per square metre; g = gram\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study found no significant differences in neonatal or maternal morbidity between early-term and full-term ECS. After adjustment for relevant maternal and neonatal factors, early-term ECS was not independently associated with composite respiratory morbidity. Although early-term infants had lower birth weights and higher rates of twin pregnancies, this did not translate into increased respiratory or metabolic complications. These findings suggest that previously reported associations between early-term ECS and neonatal respiratory morbidity may reflect confounding by underlying maternal and neonatal characteristics rather than the effect of gestational age alone. When clinically indicated and performed in well-prepared settings, early-term ECS appears to be safe, consistent with evidence from high-resource environments where advanced neonatal care mitigates risks traditionally linked to earlier delivery [17\u0026ndash;20].\u003c/p\u003e\n\u003cp\u003ePrior studies have reported increased neonatal respiratory morbidity with early-term delivery, with risk decreasing as gestational age approaches or exceeds 38 weeks [12\u0026ndash;13,21\u0026ndash;23]. Immaturity of lung fluid clearance mechanisms and reduced catecholamine surges have been proposed as underlying mechanisms [24]. The absence of significant respiratory differences in the present study may reflect careful case selection and improvements in perioperative and neonatal management. Similar to findings by Tita et al. and Thai multicenter cohorts [12,22], Al Bizri et al. reported declining respiratory morbidity and NICU admissions with advancing gestational age, without differences in mortality or Apgar scores [25].\u003c/p\u003e\n\u003cp\u003eMaternal outcomes were comparable between early-term and full-term ECS, consistent with findings from Limrungsikul et al. and Phaloprakarn et al. [22\u0026ndash;23]. Together, these data support the maternal safety of early-term ECS in well-resourced settings, while reinforcing existing recommendations to schedule elective cesarean delivery at or beyond 39 weeks to minimize preventable neonatal risk. Maternal obesity emerged as an independent predictor of neonatal respiratory morbidity, with elevated risks of respiratory distress syndrome, transient tachypnea of the newborn, and bronchopulmonary dysplasia among infants of mothers with higher pre-pregnancy BMI [26]. Altered intrauterine metabolic and inflammatory environments may adversely affect fetal lung development, increasing vulnerability to respiratory complications [27], underscoring the importance of optimizing maternal health before and during pregnancy.\u003c/p\u003e\n\u003cp\u003eDifferences in clinical characteristics reflected scheduling considerations: prior cesarean delivery was more common in early-term ECS, whereas breech presentation and large-for-gestational-age fetuses predominated at \u0026ge;39 weeks. Delaying ECS increases the likelihood of spontaneous labor and unplanned surgery, particularly in women with previous uterine scars, and emergency cesarean delivery carries higher risks of hemorrhage, infection, and anesthetic complications [10\u0026ndash;11,17]. Phaloprakarn et al. reported that spontaneous labor occurred in 41.2% of women awaiting ECS, while scheduling at 40 weeks increased it [23]. Similarly, scheduling ECS at 39 weeks has been associated with higher rates of emergency cesarean delivery, maternal intraoperative complications, and neonatal NICU admission compared with delivery at 38 weeks [17].\u003c/p\u003e\n\u003cp\u003eNeonatal respiratory morbidity in this cohort was more strongly associated with intrinsic neonatal factors and maternal metabolic status than with ECS timing within the early-term period. Neonatal factors showed the strongest associations, with male sex conferring nearly twice the risk of respiratory distress syndrome, consistent with known sex-related differences in lung maturation and surfactant production [28]. Low birth weight was also a key predictor, with affected infants exhibiting substantially higher odds of respiratory morbidity, highlighting the importance of fetal growth and maturity [29].\u003c/p\u003e\n\u003cp\u003eDespite reassuring short-term outcomes, long-term data suggest potential developmental disadvantages associated with early-term birth. Boyle et al. reported increased risks of developmental, behavioral, and health problems among children born at 37\u0026ndash;38 weeks compared with those born at 39\u0026ndash;41 weeks [30], while Shirazi et al. observed impaired early growth and psychomotor development following ECS before 39 weeks [31]. Collectively, these findings support recommendations to avoid non-medically indicated cesarean delivery before 39 weeks to optimize neonatal growth, neurodevelopment, and overall outcomes [3,6,25].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStrengths and limitations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study is strengthened by its large sample size and comprehensive evaluation of maternal and neonatal outcomes. Limitations include its retrospective design, potential selection bias, and single-center setting may limit causal inference and generalizability. In addition, long-term neonatal outcomes were not evaluated. Future prospective multicenter studies are needed to confirm these findings across diverse clinical settings. While randomized trials are unlikely due to ethical constraints, large registry-based studies could help refine recommendations on the optimal timing of elective cesarean section and assess cost-effectiveness and long-term neurodevelopmental outcomes.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eEarly-term ECS was not independently associated with neonatal respiratory morbidity. Neonatal factors and maternal obesity were stronger determinants than gestational age alone, indicating that ECS timing should be guided by overall maternal\u0026ndash;fetal risk profiles rather than gestational age in isolation.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eCS cesarean section \u003c/p\u003e\n\u003cp\u003eECS elective cesarean section \u003c/p\u003e\n\u003cp\u003eNICU Neonatal Intensive Care Unit\u003c/p\u003e\n\u003cp\u003eNICHD National Institute of Child Health and Human Development\u003c/p\u003e\n\u003cp\u003eMFMU Maternal\u0026ndash;Fetal Medicine Units Network\u003c/p\u003e\n\u003cp\u003eTTNB transient tachypnea of the newborn\u003c/p\u003e\n\u003cp\u003eRDS respiratory distress syndrome\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was reviewed and approved by the Research Ethics Committee of Hat Yai Hospital (Protocol Number HYH EC 099-67-01). The requirement for informed consent was waived, as the study utilized retrospective cohort data.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and analyzed during the current study are available from the corresponding author upon reasonable request. Data sharing is subject to approval by the health service authority and the research ethics committee.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to publish declaration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003cbr\u003e\u003c/strong\u003eNo external funding was received for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSS conceived and designed the study, performed data analysis and interpretation, and was the principal author of the manuscript. AB contributed to study design, obtained ethical approval and coordinated data collection. KK participated in data analysis and provided administrative and material support. All authors had full access to the study data, reviewed and approved the final manuscript, and accepted responsibility for the integrity and accuracy of the work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors extend their sincere appreciation to all participants and staff who contributed to this study. The authors also acknowledge the use of AI-assisted tools (ChatGPT, OpenAI) for language refinement and manuscript preparation under the authors\u0026rsquo; supervision, ensuring that all content was verified and approved by the research team.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBetran AP, Ye J, Moller AB, Souza JP, Zhang J. Trends and projections of caesarean section rates: global and regional estimates. BMJ Glob Health. 2021;6(6): e005671.\u003c/li\u003e\n\u003cli\u003ePatamasingh Na Ayudhaya O, Kittikraisak W, Phadungkiatwatana P, Hunt DR, Tomyabatra K, Chotpitayasunondh T, et al. Evaluation of cesarean delivery rates and factors associated with cesarean delivery among women enrolled in a pregnancy cohort study at two tertiary hospitals in Thailand. BMC Pregnancy Childbirth. 2024;24(1):149.\u003c/li\u003e\n\u003cli\u003eRossi AC, D\u0026rsquo;Addario V. Maternal morbidity following a trial of labor after cesarean section vs elective repeat cesarean delivery: a systematic review with meta-analysis. Am J Obstet Gynecol. 2008;199(3):224-31. doi: 10.1016/j.ajog.2008.04.025\u003c/li\u003e\n\u003cli\u003eWilmink FA, Hukkelhoven CWPM, Lunshof S, Mol BWJ, van der Post JAM, Papatsonis DNM. Neonatal outcome following elective cesarean section beyond 37 weeks of gestation: a7-year retrospective analysis of a national registry. Am J Obstet Gynecol. 2010;202(3): 250.e1-8. doi: 10.1016/j.ajog.2010.01.052 \u003c/li\u003e\n\u003cli\u003eNational Institute for Health and Care Excellence (NICE). Caesarean section. London: NICE; 2019 Sep. PMID: 31944642. \u003c/li\u003e\n\u003cli\u003eAmerican College of Obstetricians and Gynecologists\u0026rsquo; Committee on Obstetric Practice. Avoidance of nonmedically indicated early-term deliveries and associated neonatal morbidities. \u003cem\u003eObstet Gynecol.\u003c/em\u003e 2019;133(2):e156\u0026ndash;63. doi:10.1097/AOG.0000000000003077.\u003c/li\u003e\n\u003cli\u003eWorld Health Organization. WHO recommendations: non-clinical interventions to reduce unnecessary caesarean sections. Geneva: WHO; 2018.\u003c/li\u003e\n\u003cli\u003eRoberts CL, Nicholl MC, Algert CS, Ford JB, Morris JM, Chen JS. Rate of spontaneous onset of labour before planned repeat caesarean section at term. 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N Engl J Med. 2009;360(2):111\u0026ndash;20.\u003c/li\u003e\n\u003cli\u003eHansen AK, Wisborg K, Uldbjerg N, Henriksen TB. Elective caesarean section and respiratory morbidity in the term and near-term neonate. Acta Obstet Gynecol Scand. 2007;86(4):389\u0026ndash;94.\u003c/li\u003e\n\u003cli\u003eHu Y, Shen H, Landon MB, Cheng W, Liu X. Optimal timing for elective caesarean delivery in a Chinese population: a large hospital-based retrospective cohort study in Shanghai. BMJ Open. 2017;7(6):e014659. doi: 10.1136/bmjopen-2016-014659 \u003c/li\u003e\n\u003cli\u003eGlavind J, Kindberg SF, Uldbjerg N. Elective cesarean section at 38 weeks versus 39 weeks: neonatal and maternal outcomes in a randomized trial. Acta Obstet Gynecol Scand. 2013;92(5):545\u0026ndash;50.\u003c/li\u003e\n\u003cli\u003eHehir MP, Ananth CV, Siddiq Z, Flood K, Friedman AM, D\u0026rsquo;Alton ME. Cesarean delivery at 37\u0026ndash;38 weeks\u0026rsquo; gestation and neonatal morbidities: a population-based study. Am J Obstet Gynecol. 2013;209(6): 542.e1\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eTodumrong N, Somprasit C, Tanprasertkul C, Bhamarapravatana K, Suwannarurk K. A comparative study of the spontaneous labor rate in scheduled elective cesarean section at 38 weeks versus 39 weeks of gestation in parturient with previous cesarean section. J Med Assoc Thai. 2016 Jul 1;99(Suppl 4): S37-41.\u003c/li\u003e\n\u003cli\u003eSengupta S, Carrion V, Shelton J, Wynn RJ, Ryan RM, Singhal K, et al. Adverse neonatal outcomes associated with early-term birth. JAMA Pediatr. 2013;167(11):1053\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eZou L, Wang X, Ruan Y, Li G, Chen Y, Zhang W. Cesarean delivery on maternal request in southeast China. Obstet Gynecol. 2015;125(3):528\u0026ndash;36.\u003c/li\u003e\n\u003cli\u003eBarber EL, Lundsberg LS, Belanger K, Pettker CM, Funai EF, Illuzzi JL. Indications contributing to the increasing cesarean delivery rate. 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Acta Paediatr. 2004;93(5):643\u0026ndash;7.\u003c/li\u003e\n\u003cli\u003eAl Bizri A, Boghossian NS, Nassar A, Nakad P, Jaber D, Chahine R, et al. Timing of term elective cesarean section and adverse neonatal outcomes: A multi-center retrospective cohort study. PLoS One. 2021;16(4): e0249557. doi: 10.1371/journal.pone.0249557\u003c/li\u003e\n\u003cli\u003eKim YJ, Shin J, Kim TE, Lee JY, Park HJ, Choi SJ, et al. Association of maternal pre-pregnancy body mass index with neonatal respiratory outcomes: a nationwide population-based cohort study. \u003cem\u003eSci Rep.\u003c/em\u003e 2025;15:38680. doi:10.1038/s41598-025-22497-y.\u003c/li\u003e\n\u003cli\u003eMcGillick EV, Poulton S, Horgan RP, Marshall SA, Berry MJ, Dahlgren J, et al. Maternal obesity mediated predisposition to respiratory complications at birth and in later life: understanding the implications of the obesogenic intrauterine environment. \u003cem\u003ePaediatr Perinat Epidemiol\u003c/em\u003e. 2017;31 Suppl 1:19-28. doi:10.1111/ppe.12334. \u003c/li\u003e\n\u003cli\u003eFang K, Yue S, Wang S, Li X, Chen H, Zhang J, et al. The association between sex and neonatal respiratory distress syndrome. \u003cem\u003eBMC Pediatr.\u003c/em\u003e 2024;24:129. doi:10.1186/s12887-024-04596-3.\u003c/li\u003e\n\u003cli\u003eMukosha M, Jacobs C, Kaonga P, Musonda P, Vwalika B, et al. Determinants and outcomes of low birth weight among newborns at a tertiary hospital in Zambia: A retrospective cohort study. Ann Afr Med. 2023 Jul-Sep;22(3):271-278. doi: 10.4103/aam.aam_22_22. PMID: 37417013; PMCID: PMC10445713.\u003c/li\u003e\n\u003cli\u003eBoyle EM, Poulsen G, Field DJ, Kurinczuk JJ, Wolke D, Alfirevic Z, et al. Effects of gestational age at birth on health outcomes at 3 and 5 years of age: population-based cohort study. BMJ. 2012;344: e896.\u003c/li\u003e\n\u003cli\u003eShirazi M, Hajiha N, Sereshki ZK, Zarkesh MR, Shariat M, Ebrahimi M. Timing of Elective Cesarean Section and Growth and Psychomotor Developmental Indices in 6-Month-Old Infants. Archives of Iranian Medicine. 2019 Aug 1;22(8):420-8.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"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":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Elective cesarean section, Gestational age, Maternal morbidity, Neonatal respiratory complication","lastPublishedDoi":"10.21203/rs.3.rs-8675318/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8675318/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eThe optimal timing of elective cesarean section (ECS) remains controversial, requiring a balance between neonatal respiratory risk and maternal surgical safety. This study compared maternal morbidity and neonatal respiratory outcomes between early-term (\u0026lt;\u0026thinsp;39 weeks) and full-term (\u0026ge;\u0026thinsp;39 weeks) ECS.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003e A retrospective cohort study was conducted at a tertiary care hospital from January 2022 to December 2024. Women undergoing scheduled ECS were categorized as early-term (\u0026lt;\u0026thinsp;39 weeks; n\u0026thinsp;=\u0026thinsp;1,326) or full-term (\u0026ge;\u0026thinsp;39 weeks; n\u0026thinsp;=\u0026thinsp;473). Maternal characteristics, operative outcomes, and neonatal respiratory morbidity were analyzed using Chi-square and Wilcoxon rank-sum test. Multivariable logistic regression identified factors independently associated with composite neonatal respiratory morbidity.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eOf 13,745 deliveries, 5,188 (37.7%) were cesarean sections, including 1,799 eligible ECS cases (1,326 early-term and 473 full-term). The main ECS indication was the previous cesarean section (73.9%). Early-term ECS was associated with lower neonatal birth weight and a higher proportion of twin pregnancies. No significant differences were observed in operative outcomes, Apgar scores, or crude neonatal respiratory morbidity. After adjustment for maternal and neonatal factors, early-term ECS was not independently associated with composite respiratory morbidity (adjusted OR 0.77, 95% CI 0.56\u0026ndash;1.07). Maternal obesity (adjusted OR 1.40, 95% CI 1.04\u0026ndash;1.87), male sex (adjusted OR 1.94, 95% CI 1.44\u0026ndash;2.61), and low birth weight\u0026thinsp;\u0026lt;\u0026thinsp;2,500 g (adjusted OR 3.28, 95% CI 1.85\u0026ndash;5.80) were independently associated with increased odds of respiratory morbidity.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eEarly-term ECS was not independently associated with neonatal respiratory morbidity. Neonatal characteristics and maternal obesity were stronger predictors than gestational age alone, suggesting individualized, risk-based decision-making for ECS timing.\u003c/p\u003e","manuscriptTitle":"Elective cesarean section at early term versus 39 weeks or beyond: impact on neonatal respiratory outcomes and maternal morbidities in a tertiary hospital: a retrospective cohort study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-09 12:33:52","doi":"10.21203/rs.3.rs-8675318/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-04-08T01:08:10+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-25T13:30:26+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"177080566607329902379634763674972161542","date":"2026-03-08T21:09:26+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"34166639229088953037542587830815027742","date":"2026-03-04T10:21:33+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-04T18:38:51+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-01-29T19:05:55+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-01-26T11:58:33+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-26T11:57:37+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pregnancy and Childbirth","date":"2026-01-23T05:27:29+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6ce4ef6b-475e-4159-9369-6916c818b32e","owner":[],"postedDate":"February 9th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-02-09T12:33:52+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-09 12:33:52","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8675318","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8675318","identity":"rs-8675318","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}