Tita, A. T. N., Landon, M. B., Spong, C. Y., Lai, Y., Leveno, K. J., Varner, M. W., et al. (2009).New England Journal of Medicine, 360(2), 111-120.
This multicenter study was conducted at 19 maternal-fetal medicine units from 1999 through 2002. Participants were 13,258 women with viable singleton pregnancies who had elective repeat cesareans out of the population of 28,867 women who delivered by repeat cesarean. These women had no recognized indications for birth before 39 weeks' gestation and all cesareans were performed before the onset of labor. Outcome variables were neonatal death, respiratory complications, treated hypoglycemia, newborn sepsis, and admission to the neonatal intensive care unit (NICU). Those women who delivered before term were more likely to have infants with birth weights below 2500 grams and infants who were small for gestational age. The infants born to these women were more likely to have adverse outcomes, including respiratory distress syndrome, transient tachypnea of the newborn, admission to the NICU, newborn sepsis, or treated hypoglycemia. They were more likely to require cardiopulmonary resuscitation or ventilation during the first day of life and were more likely to remain in the hospital for 5 or more days.
Almost 25% of births in the United States are delivered by primary cesarean. Most women who have had a cesarean are opting for repeat cesareans, and many of these repeat cesarean deliveries are performed before 39 completed weeks of gestation. This timing may be due to the physician's desire to schedule the procedure at a convenient time or the woman's desire to give birth as soon as she has reached term. The findings from this study are important when counseling women about the dangers of setting the dates for elective repeat cesareans in pregnancies without complications earlier than 39 completed weeks' gestation.