Cervical ripening balloon with and without oxytocin in multiparas: a randomized controlled trial.

BACKGROUND: The optimal method for induction of labor for multiparous women with an unfavorable cervix is unknown.

OBJECTIVE: We sought to determine if induction of labor with simultaneous use of oxytocin and a cervical ripening balloon, compared with sequential use, increases the likelihood of delivery within 24 hours in multiparous women.

STUDY DESIGN: We performed a randomized controlled trial from November 2014 through June 2017. Eligible participants were multiparous women with a vertex presenting, nonanomalous singleton gestation ≥34 weeks undergoing induction of labor. Women were excluded for admission cervical examination >2 cm, ruptured membranes, chorioamnionitis or evidence of systemic infection, placental abruption, low-lying placenta, >1 prior cesarean delivery, or contraindication to vaginal delivery. Patients were randomly allocated to the following cervical ripening groups: simultaneous (oxytocin with cervical ripening balloon) or sequential (oxytocin following cervical ripening balloon expulsion). The primary outcome was delivery within 24 hours of cervical ripening balloon placement. Secondary outcomes included induction-to-delivery interval, time to cervical ripening balloon expulsion, mode of delivery, and adverse maternal or neonatal outcomes.

RESULTS: In all, 180 patients were randomized (90 simultaneous, 90 sequential). Baseline demographic and obstetric characteristics were similar between study groups. Women in the simultaneous group were significantly more likely to deliver within 24 hours of cervical ripening balloon placement compared to the sequential group (87.8% vs 73.3%, P = .02). The simultaneous group also had a significantly shorter induction-to-delivery interval and greater cervical dilation at cervical ripening balloon expulsion. There were no differences in mode of delivery, chorioamnionitis, or adverse maternal or neonatal outcomes.

CONCLUSION: In multiparous women with an unfavorable cervix, the simultaneous use of cervical ripening balloon and oxytocin results in an increased frequency of delivery within 24 hours and a shorter induction-to-delivery interval.