Background: Induction of labor (IOL) is a common practice in many parts of the world. However, the benefits and risks of preventive IOL for the mother and baby have yet to be critically assessed. This study is to investigate the effects of preventive IOL for non-urgent indications at term on maternal and neonatal outcomes.
Methods: In this study, we applied a propensity score model to mimic a randomized clinical trial. Maternal and neonatal outcomes were compared between women with preventive IOL at 37-39 weeks of gestation and women with ongoing pregnancy (expectant management). The subjects were from the Consortium on Safe Labor, a study of over 200,000 births from 19 hospitals across the US from 2002 to 2008.
Results: Both nulliparous and multiparous women induced preventively for non-urgent indications at 37-38 weeks' gestation had lower rates of cesarean delivery compared to those delivered at later gestational weeks. However, preventive IOL was associated with increased risks of adverse neonatal outcomes (adjusted odds ratio [aOR] = 1.68, 95% confidence interval [CI], 0.97-2.92 for nulliparas; aOR = 2.22, 1.32-3.74 for multiparas) and admission to NICU (aOR = 1.48, 0.99-2.20 for nulliparas; aOR = 2.08, 1.47-2.96 for multiparas) at 37 weeks' gestation. A longer maternal hospital stay was found among all women with preventive IOL.
Conclusions: Preventive IOL for non-urgent indications may be associated with a decreased risk of cesarean delivery at early term but increased risks of adverse neonatal outcomes at 37 weeks. It also results in a longer hospital stay than expectant management.
Keywords: Cesarean delivery; Maternal outcomes; Neonatal outcomes; Preventive induction of labor; Propensity score model.