Timing of delivery and adverse outcomes in term singleton repeat cesarean deliveries

To compare the maternal and neonatal risks of elective repeat cesarean delivery compared with pregnancy continuation at different gestational ages, starting from 37 weeks.

We analyzed the composite maternal and neonatal outcomes of repeat cesarean deliveries studied prospectively over 4 years at 19 U.S. centers. Maternal outcome was a composite of pulmonary edema, cesarean hysterectomy, pelvic abscess, thromboembolism, pneumonia, transfusion, or death. Composite neonatal outcome consisted of respiratory distress, transient tachypnea, necrotizing enterocolitis, sepsis, ventilation, seizure, hypoxic-ischemic encephalopathy, neonatal intensive care unit admission, 5-minute Apgar of 3 or lower, or death. Outcomes after elective repeat cesarean delivery without labor at each specific gestational age were compared with outcomes for all who were delivered later as a result of labor onset, specific obstetric indications, or both.

Twenty-three thousand seven hundred ninety-four repeat cesarean deliveries were included. Elective delivery at 37 weeks of gestation had significantly higher risks of adverse maternal outcome (odds ratio [OR] 1.56, 95% confidence interval [CI] 1.06-2.31), whereas elective delivery at 39 weeks of gestation was associated with better maternal outcome when compared with pregnancy continuation (OR 0.51, 95% CI 0.36-0.72). Elective repeat cesarean deliveries at 37 and 38 weeks of gestation had significantly higher risks of adverse neonatal outcome (37 weeks OR 2.02, 95% CI 1.73-2.36; 38 weeks OR 1.39 95% CI 1.24-1.56), whereas delivery at 39 and 40 weeks of gestation presented better neonatal outcome as opposed to pregnancy continuation (39 weeks OR 0.79, 95% CI 0.68-0.92; 40 weeks OR 0.57, 95% CI 0.43-0.75).

In women with prior cesarean delivery, 39 weeks of gestation is the optimal time for repeat cesarean delivery for both mother and neonate.