Low-dose vaginal misoprostol vs vaginal dinoprostone insert for induction of labor beyond 41st week: A randomized trial.

INTRODUCTION: The aim of this study was to compare the efficacy and safety of a low-dose protocol of vaginal misoprostol and vaginal dinoprostone insert for induction of labor in women with post-term pregnancies.

MATERIAL AND METHODS: We designed a prospective, randomized, open-labeled trial with evaluators blinded to the end-point, including women of at least 41 weeks of gestational age with uncomplicated singleton pregnancies and a Bishop score <6. They were randomized into dinoprostone or misoprostol groups in a 1:1 ratio. Baseline maternal data and perinatal outcomes were recorded for statistical analysis. Successful vaginal delivery within 24 hours was the primary outcome variable. A P value <0.05 was considered statistically significant. This study was registered in ClinicalTrials.gov (number NTC03744364).

RESULTS: We included 198 women for analysis (99 women in each group). Vaginal birth rate within 24 hours did not differ between groups (49.5% vs 42.4%; P = 0.412). When the Bishop score was <4, dinoprostone insert showed a higher probability of vaginal delivery within 12 hours (17.8% vs 4%; P = 0.012). In the dinoprostone group, removal of the insert was more likely to be due to an adverse event (5.1% vs 14.1%; P = 0.051) and an abnormal fetal heart rate pattern during active labor (44.4% vs 58.6%; P = 0.047). Both groups were similar in neonatal outcomes including Apgar score, umbilical cord pH and neonatal intensive care unit admission.

CONCLUSIONS: Low-dose vaginal misoprostol and vaginal dinoprostone insert seem to be equally effective and safe for induction of labor in pregnant women with a gestational age beyond 41 weeks.