Maternal and neonatal morbidity among nulliparous women undergoing elective induction of labor

Abstract

Objective: To determine rates of adverse maternal and neonatal outcomes among nulliparous women undergoing elective labor induction compared with spontaneous labor.

Study design: Retrospective chart review of term, nulliparous women with singleton gestations in 2007. Elective induction was defined as induction occurring from 37(0/7) to 41(0/7) weeks without ruptured membranes, fetal/maternal complications, or abnormal fetal testing. The primary outcome was cesarean delivery; secondary outcomes were maternal and fetal complications. Continuous variables were compared with t test and Mann-Whitney U, categorical with chi2 and Fisher's exact test. Logististic and linear regression were used to control for confounders and to assess independent effects of induction.

Results: Of850 nulliparous, singleton, term deliveries, 485 met criteria for inclusion. Cesarean delivery rate was 19.8% in the labor group and 33.6% in the induction group (p = 0.002). Odds ratio for cesarean was 2.1 (p = 0.001), 1.8 after adjustment for gestational age and birth weight, (p = 0.01). Length of stay (LOS) was significantly associated with induction even after adjustment for cesarean (beta = 0.7, p < 0.001). Rates ofepidural, postpartum hemorrhage, pediatric delivery attendance and neonatal oxygen requirement were higher with induction, before and after adjustment (p < 0.05).

Conclusion: Elective induction of labor in nulliparas is associated with increased rates of cesarean, postpartum hemorrhage, neonatal resuscitation and longer LOS without improvement in neonatal outcomes.