Some obstetricians believe that a planned cesarean delivery is associated with less morbidity than a trial of labor when the increased rates of complication associated with an unplanned cesarean delivery following an unsuccessful trial are considered. Others believe that the morbidity attributed to a trial of labor is unfounded and support the choice of a trial of labor over a planned cesarean. Because of lack of consensus on which delivery route should be preferred, there have been shifting attitudes among practitioners with respect to choice of route, and in recent years, more patients choose a cesarean delivery. Most studies regarding this phenomenon have focused on short-term outcomes associated with the initial pregnancy. However, the choice of route of delivery in the initial pregnancy affects subsequent pregnancies via the increased morbidity associated with multiple abdominal surgeries and uterine scars. Few data are available on the comparative morbidity across multiple pregnancies related to the initial route of delivery.
This study estimated cumulative risks over multiple pregnancies associated with the choice of an elective cesarean for the initial delivery. A decision analytic model was designed to compare the risks over a woman’s reproductive life span following the choice of either trial of labor or elective cesarean delivery for the first delivery. The model assessed 5 adverse maternal obstetric outcomes: maternal transfusion, operative injury, deep venous thrombosis, hysterectomy, and death. The model also evaluated neonatal outcomes of cerebral palsy and permanent brachial plexus palsy in the offspring. The risk in each pregnancy of composite maternal morbidity associated with the choice of elective primary cesarean delivery was estimated as well as the cumulative risk according to the total number of pregnancies.
The choice of a cesarean delivery with the first pregnancy resulted in a 0.3% increased risk of a major adverse maternal outcome. With each subsequent pregnancy, the difference in attributable risk increased. By the fourth pregnancy, the cumulative risk of the composite adverse outcome for the choice of an elective cesarean for the first delivery increased to nearly 10% compared with 3.5% for the initial choice of a trial of labor. With respect to neonatal outcomes, cerebral palsy and brachial plexus palsy occurred less frequently in the first pregnancy with an elective cesarean delivery compared with a trial of labor (2.4 and 0.41 fewer cases of cerebral palsy and brachial plexus palsy, respectively, per 10,000 women). However, by the fourth pregnancy, the risk of adverse neonatal outcome was marginally higher among offspring of women who had undergone an initial elective cesarean delivery (0.368% vs 0.363%).
These data show that the risk of maternal morbidity associated with the choice of primary elective cesarean delivery increased with each subsequent pregnancy and was higher than that associated with the initial choice of a trial of labor. However, the study did not find that the increased maternal risk was offset by a substantive reduction in the risk of neonatal morbidity. Rather, neonatal risks were only marginally decreased in the primary elective cesarean delivery group and were attenuated by the time of the fourth pregnancy.