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

OBJECTIVE: To compare the maternal and neonatal risks of elective repeat cesarean delivery compared with pregnancy continuation at different gestational ages, starting from 37 weeks. METHODS: 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. RESULTS: 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% CI1.24-1.56), 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). CONCLUSION: In women with prior cesarean delivery, 39 weeks of gestation is the optimal time for repeat cesarean delivery for both mother and neonate.