OBJECTIVE: To measure decision-to-incision intervals and related maternal and neonatal outcomes in a cohort of women undergoing emergency cesarean deliveries at multiple university-based hospitals comprising the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. METHODS: All women undergoing a primary cesarean delivery at a Network center during a 2-year time span were prospectively ascertained. Emergency procedures were defined as those performed for umbilical cord prolapse, placental abruption, placenta previa with hemorrhage, nonreassuring fetal heart rate pattern, or uterine rupture. Detailed information regarding maternal and neonatal outcomes, including the interval from the decision time to perform cesarean delivery to the actual skin incision, was collected. RESULTS: Of the 11,481 primary cesarean deliveries, 2,808 were performed for an emergency indication. Of these, 1,814 (65%) began within 30 minutes of the decision to operate. Maternal complication rates, including endometritis, wound infection, and operative injury, were not related to the decision-to-incision interval. Measures of newborn compromise including umbilical artery pH less than 7 and intubation in the delivery room were significantly greater when the cesarean delivery was commenced within 30 minutes, likely attesting to the need for expedited delivery. Of the infants with indications for an emergency cesarean delivery who were delivered more than 30 minutes after the decision to operate, 95% did not experience a measure of newborn compromise. CONCLUSION: Approximately one third of primary cesarean deliveries performed for emergency indications are commenced more than 30 minutes after the decision to operate, and the majority were for nonreassuring heart rate tracings. In these cases, adverse neonatal outcomes were not increased. © 2006 by The American College of Obstetricians and Gynecologists. Published by Lippincott Williams & Wilkins.