Objective: To compare pregnancy outcomes following induction of labor with prostaglandins versus extra-amniotic balloon catheter indicated for term isolated oligohydramnios.
Study design: Retrospective cohort study of all women who underwent induction of labor due to term isolated oligohydramnios at a university affiliated medical center (2007-2016). The cohort was divided into two subgroups, according to induction method: vaginal prostaglandins E2 versus extra-amniotic balloon catheter. Primary outcomes were successful cervical ripening, defined as a Bishop score ≥ 8, and vaginal delivery rate. Secondary outcomes were neonatal adverse events.
Results: Five hundred and ten women were included, of whom 454 (89%) underwent induction by prostaglandins and 56 (11%) by extra-amniotic balloon. Cervical ripening success rate was significantly higher in the prostaglandins group (89.4 vs. 76.79%, p = 0.006), as was the rate of vaginal delivery (77.53 vs. 48.21%, p < 0.0001). Induction with prostaglandins remained superior to extra-amniotic balloon in vaginal delivery rate following adjustment to potential confounders (aOR 3.470, 95% CI 1.296-9.296, p < 0.0001). Neonates delivered following induction with extra-amniotic balloon catheter were more often admitted to the neonatal intensive care unit (14.55 vs. 3.39%, p = 0.002).
Conclusion: Both prostaglandins and extra-amniotic balloon catheter are reasonable interventions for isolated term oligohydramnios. Prostaglandins were superior to extra-amniotic balloon both in cervical ripening success and in vaginal delivery rates.
Keywords: Extra-amniotic balloon; Induction of labor; Oligohydramnios; Prostaglandins; Term.