Health implications resulting from the timing of elective cesarean delivery

The literature is nearly unanimous in recommending elective cesarean delivery at 39 weeks of gestation because of the lower rates of neonatal respiratory complications compared to 38 weeks. However, elective cesarean delivery at 39 weeks or more may have maternal and other fetal consequences compared to delivery at 38 weeks, which are not always addressed in these studies.

Between 38 and 39 weeks of gestation, approximately 10% - 14% of women go into spontaneous labor; meaning that a considerable number of women scheduled for an elective cesarean delivery at 39 weeks will deliver earlier in an unscheduled, frequently emergency, cesarean delivery. The incidence of maternal morbidity and mortality is higher among women undergoing non-elective cesarean deliveries than among those undergoing elective ones. Complications may be greater among women after numerous repeat cesarean deliveries and among older women. Other than reducing the frequency of non-elective cesarean deliveries, bringing forward the timing of elective cesarean delivery to 38 weeks, may occasionally prevent intrauterine fetal demise which has been shown to increase with increasing gestational age and to avoid other fetal consequences related to the emergency delivery. All these considerations need to be weighed against the medical and the economic impact of the increase in neonatal morbidity resulting from births at 38 weeks compared to 39 weeks.

Until prospective randomized trials are conducted, we are unlikely to be able to precisely answer all risk:benefit questions as to the best timing of scheduled elective cesarean delivery. Older women, and women with numerous prior cesarean deliveries, are of particular concern. It is reasonable to inform the pregnant women of the risk of each of the above options and to respect her autonomy and decision-making.