(341) Two is not better than one balloon for cervical ripening

Objective:
Cervical ripening with single-balloon catheters is safe and effective. Shorter balloon dwell time (6 vs.12 h) shortens time from insertion to delivery without increasing cesarean rates, but optimal management after removal when the cervix remains unfavorable is unclear. Sequential placement of a second balloon has been described, but without supporting data. We hypothesized this may increase risk of cesarean delivery (CD) and infection.

Study Design:

In this retrospective cohort study, we reviewed records of term gravidas (≥37 weeks) who underwent cervical balloon ripening at our institution between January 1, 2020, and January 1, 2025. Patients with inadequate cervical dilation (≤3 cm after initial foley balloon) were included. They were grouped by single (Group 1) or two sequential (Group 2) balloon placements, matched 3:1. The study was powered to detect a 15% increase in CD and intra-amniotic infection rates, treated as independent primary outcomes. Secondary outcomes included time to delivery and postpartum hemorrhage. Multivariable logistic regression adjusted for maternal age, BMI, gestational age, and initial bishop score. Significance was defined as p < 0.05.

Results:
During the study period, 799 participants met inclusion criteria, with 582 in group 1 and 217 in group 2. The CD (19.8% vs. 56.2% p< 0.0001) and chorioamnionitis (15.3% vs. 35.5%, p, 0.0001) rates were significantly lower in group 1. On multiple logistic regression, second balloon placement was independently associated with increased odds of CD (aOR 2.7, 95% CI 1.8–4.1) and intra-amniotic infection (aOR 1.8, 95% CI 1.2–2.9). The incidence of postpartum hemorrhage was higher in group 2 (8.3% vs. 3.3%, p = 0.003), though this was not significant after adjusting for mode of delivery. 

Conclusion:
Our findings align with previous studies that suggest safety and efficacy of shorter balloon duration time. Based on our data, we do not recommend placement of a second sequential cervical ripening balloon, as it is associated with significantly higher odds of cesarean delivery and chorioamnionitis, and increased risk for harm.