Delivery mode after cervical ripening among patients with no prior vaginal births

To compare mode of delivery and maternal and neonatal outcomes using cervical ripening balloon (CRB) for induction of labor (IOL) in nulliparous patients vs. those undergoing first trial of labor after cesarean (TOLAC).

Retrospective cohort study including data from two tertiary medical centers. Included were all patients with a singleton pregnancy and a gestational age > 37+0 weeks and no prior vaginal birth undergoing IOL with CRB. Nulliparous patients (nulliparous group) were compared to patients with one prior cesarean delivery (CD) and no prior vaginal delivery (TOLAC group). Patients who withdrew consent for trial of labor at any time in both groups were excluded. The primary outcome was mode of delivery.

Overall, 161 patients were included in the TOLAC group and 1577 in the nulliparous group. The rate of CD was similar in both groups and remained similar after adjusting for confounders (29.8 % vs. 28.9 %, p = 0.86, OR 1.1, 95 %, CI 0.76-1.58). CD due to fetal distress was more common in the TOLAC group (75 % vs. 56 %, p = 0.014). Other maternal outcomes and neonatal outcomes were similar in the two groups.

Comparable vaginal delivery rates may be achieved in patients with or without a previous CD attempting their first trial of labor, with a cervical ripening balloon for labor induction, without increasing adverse maternal or neonatal outcomes.