Objective: To determine the effects of elective induction on the risk of cesarean delivery in a cohort of women with low-risk term pregnancies and to evaluate the costs of elective induction services within our hospital system.
Methods: Records of 1135 eligible women with low-risk, singleton, vertex pregnancies at 38–41 weeks' gestation who were eligible for vaginal delivery were analyzed retrospectively after elective induction (n = 263) or spontaneous labor (n = 872). Outcome measures included cesarean delivery and direct costs. Variables evaluated were parity, maternal age, estimated gestational age, birth weight, prior cesarean delivery, epidural anesthetic use, and provider category. Analysis was by univariable and multivariable regression modeling.
Results: Elective induction placed nulliparas at a twofold higher risk for cesarean delivery (odds ratio 2.4, 95% confidence interval 1.2, 4.9) after adjustment for birth weight, maternal age, and gestational age. We found a significantly increased risk of cesarean delivery with increased birth weight for nulliparas (2–66.7%). Increasing maternal age increased the risk of cesarean delivery in all parity groups (P < .05), but particularly among nulliparas (3–26.3%) (P < .001). Electively induced labors that ended in vaginal delivery cost $273 more and required an average of 4 hours more in the hospital before delivery than did noninduced vaginal deliveries (P < .001).
Conclusion: Elective induction significantly increased the risk of cesarean delivery for nulliparas, and increased inhospital predelivery time and costs.
From 1983 through 1996, induction rates worldwide ranged between 7.5% and 26%, with trends of increasing rates in the most recent years.1–6 In our hospital system, the rate for all inductions was 23.2% in 1997. Studies of induction have continued to combine low-and high-risk pregnancies, preterm and term inductions, indicated and elective inductions, and induction techniques. There is continued criticism of the adequacy of control groups and statistical techniques used to evaluate reported results.
The purpose of this study was to determine whether deliveries with elective induction were associated with greater risk of cesarean delivery or higher costs because of increased in-hospital resource use compared with noninduced deliveries in a cohort of women with low-risk term pregnancies, some of whom underwent elective induction of labor.