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

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

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.

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).

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.