Elective induction of labor at term compared with expectant management: maternal and neonatal outcomes

Abstract

Objective: To test the association of elective induction of labor at term compared with expectant management and maternal and neonatal outcomes.

Methods: This was a retrospective cohort study of all deliveries without prior cesarean delivery in California in 2006 using linked hospital discharge and vital statistics data. We compared elective induction at each term gestational age (37-40 weeks) as defined by The Joint Commission with expectant management in vertex, nonanomalous, singleton deliveries. We used multivariable logistic regression to test the association of elective induction and cesarean delivery, operative vaginal delivery, maternal third- or fourth-degree lacerations, perinatal death, neonatal intensive care unit admission, respiratory distress, shoulder dystocia, hyperbilirubinemia, and macrosomia (birth weight greater than 4,000 g) at each gestational week, stratified by parity.

Results: The cesarean delivery rate was 16%, perinatal mortality was 0.2%, and neonatal intensive care unit admission was 6.2% (N=362,154). The odds of cesarean delivery were lower among women with elective induction compared with expectant management across all gestational ages and parity (37 weeks [odds ratio (OR) 0.44, 95% confidence interval (CI) 0.34-0.57], 38 weeks [OR 0.43, 95% CI 0.38-0.50], 39 weeks [OR 0.46, 95% CI 0.41-0.52], 40 weeks [OR 0.57, CI 0.50-0.65]). Elective induction was not associated with increased odds of severe lacerations, operative vaginal delivery, perinatal death, neonatal intensive care unit admission, respiratory distress, shoulder dystocia, or macrosomia at any term gestational age. Elective induction was associated with increased odds of hyperbilirubinemia at 37 and 38 weeks of gestation and shoulder dystocia at 39 weeks of gestation.

Conclusion: Elective induction of labor is associated with decreased odds of cesarean delivery when compared with expectant management.

Level of evidence: : II.

Fig. 1

Sample flow and comparison groups for elective induction of labor compared with expectant management, California deliveries, 2006. Expectant management indicates that the women went on to deliver at some later gestational age regardless of induction or mode of delivery (eg, vaginal or cesarean delivery). *Some women may have more than one exclusion criterion; these numbers do not necessarily represent the total frequency of each exclusion in the dataset. ^†At each gestational week, spontaneous deliveries that week and women with antenatal indications for delivery are excluded; thus, at 37 weeks of gestation, the induction group plus the expectant group does not equal the sample total. ^‡Compared with expectant management and delivery at 38–42 weeks of gestation (n=305,876). ^§Compared with expectant management and delivery at 39–42 weeks of gestation (n=242,473). ^∥Compared with expectant management and delivery at 40–42 weeks of gestation (n=144,898). ^¶Compared with expectant management and delivery at 41 or 42 weeks of gestation (n=54,517).