Risk factors and ramifications offailure to achieve cervical ripening with prostaglandins – Retrospective Cohort Study

Background: Induction of labor (IOL) with prostaglandins is a common obstetric procedure. We aimed to assess baseline characteristics and evaluate the outcomes of women who failed to respond to labor induction. Methods: Retrospective cohort analysis of all women with singleton gestation who underwent induction of labor, due to prolonged pregnancy, with a slow release prostaglandin-E2 (PGE2) vaginal insert (PROPESS) for cervical ripening. During the study period (2012–2018), 1285 were analyzed. They were divided into 3 subgroups accordingly: a) responders − 1,202 (93.54%) - achieved ripening; b) partial responders − 39 (3.04%) – achieved partial ripening and proceeded to oxytocin augmentation; and c) non responders − 44 (3.42%) - required a second ripening method with extra amniotic foley catheter balloon (EAB). Baseline characteristics and labor outcomes were compared between the groups. Primary outcome was defined as intrapartum cesarean delivery (CD) rate. Secondary outcomes were defined as composite adverse maternal and composite adverse neonatal outcomes. A multivariant analysis was utilized to adjust outcomes to potential confounders. Results: Women in the responders’ group were younger (30.03 vs. 32.13 and 31.32 years, p = 0.005), and had lower rates of primiparity (76.92% and 81.39% vs 50.99%, p < 0.001). Women in the responders group less frequently required intrapartum cesarean delivery (3.49% vs. 33.33% and 36.36%, p < 0.001). Failure to achieve a cervical ripening with PGE2 (both non-responders and partial responders) was found to be an independent risk factor for cesarean delivery following multivariate analysis (aOR 11.90, 95% CI 6.13–23.25). Conclusion: Women who fail to achieve cervical ripening with PGE2 are older, and more often primiparous. This group is associated with higher rates of intrapartum cesarean delivery and adverse outcomes.