Maternal and neonatal outcomes of pregnancies complicated by late fetal growth restriction undergoing induction of labor with dinoprostone compared with cervical balloon: A retrospective, international study

Introduction: The aim of this study was to compare vaginal dinoprostone and mechanical methods for induction of labor (IOL) in pregnancies complicated by late fetal growth restriction. Material and methods: Multicenter, retrospective, cohort study involving six referral centers in Italy and Spain. Inclusion criteria were pregnancies complicated by late fetal growth restriction as defined by Delphi consensus criteria. The primary outcome was the occurrence of uterine tachysystole; secondary outcomes were either cesarean delivery or operative vaginal delivery for non-reassuring fetal status, a composite score of adverse neonatal outcome and admission to neonatal intensive care unit (NICU). Univariate and multivariate logistic regression analysis was used to analyze the data. Results: A total of 571 pregnancies complicated by late fetal growth restriction undergoing IOL (391 with dinoprostone and 180 with mechanical methods) were included in the analysis. The incidence of uterine tachysystole (19.2% vs. 5.6%; p = 0.001) was higher in women undergoing IOL with dinoprostone than in those undergoing IOL with mechanical methods. Similarly, the incidence of cesarean delivery or operative delivery for non-reassuring fetal status (25.6% vs. 17.2%; p = 0.027), composite adverse neonatal outcome (26.1% vs. 16.7%; p = 0.013) and NICU admission (16.9% vs. 5.6%; p < 0.001) was higher in women undergoing IOL with dinoprostone than in those undergoing IOL with mechanical methods. At logistic regression analysis, IOL with mechanical methods was associated with a significantly lower risk of uterine tachysystole (odds ratio 0.26, 95% confidence interval 0.13-0.54; p < 0.001). Conclusions: In pregnancies complicated by late fetal growth restriction, IOL with mechanical methods is associated with a lower risk of uterine tachysystole, cesarean delivery or operative delivery for non-reassuring fetal status, and adverse neonatal outcome compared with pharmacological methods.