Time matters: Cervical ripening balloon for 6 versus 12 h-Retrospective comparison between two protocols.

Objective: Recently, two randomized controlled trials compared removal of cervical ripening balloon (CRB) after 6 versus 12 h. Their results showed similar Bishop score changes in both groups and a shorter time to delivery in the 6-h group. Neither of the studies was powered to show difference in mode of delivery. The aim of this study was to compare mode of delivery when the CRB was removed after 6 versus 12 h.

Methods: A historical control study comparing induction of labor with a CRB between two time periods, one in which the CRB was removed after 12 h (12-h group), and the other in which it was removed after 6 h (6-h group). We included term pregnancies with a singleton fetus in vertex presentation. We excluded patients with a previous cesarean delivery, failed ripening with prostaglandins prior to CRB insertion, and any contraindication for vaginal delivery. The primary outcome was mode of delivery. Secondary outcomes included delivery within 24 h and other maternal and neonatal outcomes.

Results: We included 1704 patients, 914 in the 12-h group, and 717 in the 6-h group. Removal after 6 h was associated with a lower rate of cesarean and instrumental deliveries (28.6% vs 22.5%, and 12% vs 6.2%, respectively) and a higher rate of vaginal delivery within 24 h. All differences were statistically significant.

Conclusion: Removing a cervical ripening balloon after 6 rather than 12 h is associated with reduced cesarean and instrumental delivery rates, and should be considered as a reasonable, and potentially superior alternative in labor induction protocols with intracervical ripening balloon.