Timing Of Elective Cesarean Section At Term And Neonatal Respiratory Morbidity

OBJECTIVE:We sought to evaluate the relationship between the timing of the elective cesarean section performed at term and the neonatal respiratory morbidity.Determining the optimal timing of the elective cesarean section, in order to guide obstetric clinical practice.METHODS:We conducted a retrospective study of the women and their neonates, who accepted the elective cesarean section at term in Shandong Province Hospital and Shandong Maternity Hospital from December 2007 to November 2010. Women with viable singleton pregnancies delivered before the PROM or the onset of labor, and with some certain indications for cesarean section (social factor, scar uterine, breech presentation, precious fetus, first delivery after 35ys old, IVF-ET, combined with uterine myoma or ovarian tumor) were included. All maternal and neonatal data were compared with one-way ANOVA. Neonatal respiratory morbidity of different gestational age, including total respiratory morbidity and each of respiratory morbidity, were compared with chi-square test. Logistic regression was used to study the association between neonatal respiratory morbidity and gestational age at delivery (370+6 and 380+6 weeks) relative to 390+6 week of gestation. For neonatal respiratory morbidity, we calculated the odd ratio(OR) and their 95% confidence interval(CI) and unadjusted and adjusted for potential confounders.RESULTS:2094 cesarean sections were performed electively in our study; and of these,1055(50.4%) elective cesarean sections were performed before 39 gestational weeks(8.3%at 37 weeks and 42.1% at 38 weeks), while 1039(49.6%) at 390+6 weeks of gestation. Neonates born at 370+6 or 380+6 weeks of gestation were, compared to these neonates born at 390+6 weeks of gestation, at significantly higher risk for the total neonatal respiratory morbidity. The absolute risks were 6.5% at 370+6 4.5% at 380+6 weeks compared with 2.5% at 390+6 weeks of gestation(P=0.006). Adjusted ORs(95%CI) for the total neonatal respiratory morbidity at 370+6 and 380+6 weeks were OR=2.5 (95%CI:1.2-5.1), and 1.8 (95%CI:1.1-2.9). Further analysis, the risks for wet lung were also significantly higher when elective cesarean sections were performed before 39 weeks of gestation.CONCLUSION:Elective cesarean section performed before 39 weeks of gestation is common. Nevertheless, it can increase the incidence of the neonatal respiratory morbidity.