Objective: To determine whether obstetricians with high rates of induction for the indication of fetal macrosomia had higher or lower cesarean section rates.
Study design: Data were analyzed from 1432 deliveries with birthweights > 4000 g. Four physician populations were identified: a faculty service and three groups of private practitioners with induction rates 20% to 40%, 40% to 60% and > 60%. The average cesarean section rate was determined for each group as well as the percentage of each group's deliveries occurring before 39 weeks, at 39, at 40, and after 40 weeks. In addition, the relative risk of cesarean delivery was calculated for the entire study population.
Results: No correlation was found between the rate of induction of labor and the rate of cesarean section. Delivery of nulliparous and multiparous patients after 40 weeks carried an increased risk of cesarean section. Delivery of multiparous patients before 39 weeks did also. Obstetricians with induction rates > 40% significantly decreased the incidence of delivery after 40 weeks, which lowered their cesarean section rates, but no net lowering occurred because of increased rate of cesarean section < 39 weeks.
Conclusion: A fetal weight of 4000 g or more is not an indication for induction of labor. For multiparous patients, induction at 38 weeks or before is associated with an increased rate of cesarean delivery.