330: Comparison of two management options for labor induction following unsuccessful prostaglandin E2 ripening


      We sought to evaluate whether cervical ripening with a foley balloon, in addition to oxytocin, increases the likelihood of a vaginal delivery (VD) compared to oxytocin alone in nulliparous women who did not respond to treatment with prostaglandin E2 (PGE2).

      Study Design

      We a performed a retrospective cohort study of labor induction in singleton, term, nulliparas that underwent cervical ripening with vaginal PGE2 insert from October 2015 to March 2019. Patients who did not respond to PGE2 ripening (bishop score (BS) < 6 or cervical dilation < 3cm) were stratified into 2 groups based on management: sequential ripening with foley balloon in addition to oxytocin (n = 123) versus oxytocin alone (n = 149). Patients who had PGE2 for < 6 hours, a BS > 6, rupture of membranes or missing data were excluded. We compared the rate of VD between the groups as well as several maternal and neonatal outcomes. Chi-Squared, Fisher’s exact and Wilcoxon tests were used for statistical analysis. Logistic regression was used to calculate odds ratios (ORs) and adjust for significant confounders. For time to delivery, a Cox proportional hazard regression was used to determine the hazard ratio (HR) and adjusted HR.


      840 patients underwent cervical ripening with PGE2 during the study period. After the exclusion criteria were applied, 272 cases comprised the study cohort. Of those, 123 (45%) continued labor induction with foley balloon and oxytocin and 149 (55%) continued labor induction with oxytocin alone. Baseline characteristics are reported in Table 1. There was no difference (aOR 1.61, p = 0.07) in the likelihood of VD between the two groups (Table 2). There was no statistically significant difference in adverse maternal or neonatal outcomes (Table 2).


      Our data did not show a difference in VD rate in nulliparous women unresponsive to PGE2 ripening that underwent continued induction with oxytocin and foley balloon compared to oxytocin alone. Larger studies investigating the utility of sequential ripening and determining the optimal induction method following unsuccessful ripening are needed.
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