Outpatient Cervical Ripening: A Multicentered Retrospective Cohort Study [ID: 1377444

Abstract

INTRODUCTION: This study aims to compare safety and effectiveness between different outpatient cervical ripening (CR) methods. METHODS: Seven community and academic hospitals in the Greater Toronto Area that performed outpatient CR participated. We reviewed eligible charts over 12–24 months based on predetermined criteria. Multivariable analyses were performed; covariates included nulliparity, cervical unfavourability, and maternal and gestational age. Binary outcomes were modeled using logistic regression, presented as adjusted odds ratio (OR) with 95% CI. Time-to-event outcomes were described using unadjusted Kaplan-Meier curves. Multivariable time-to-event analyses were performed using accelerated failure time models with effects presented as time ratios (TRs) with 95% CI. RESULTS: We identified 1,910 pregnancies that underwent outpatient CR using balloon catheters in 881 (46%), dinoprostone vaginal inserts (DVIs) in 553 (29%), and dinoprostone vaginal gel/tablets (DG/T) in 476 (25%) pregnancies. The choice of agent varied considerably per site; one site used balloon catheters in 95%, another used DG/T in 95%, and three sites used DVI in more than 74% of cases. There were no differences in cesarean deliveries or adverse events related to CR. Compared to balloon catheters, patients with pharmacological ripening more often needed a subsequent ripening agent (DVI adjusted odds ratio 2.32 [1.62, 2.81], DG/T 3.26 [2.44, 4.36]). CR-to-delivery time did not differ, but compared to balloon catheters, DG/T had a shorter admission-to-delivery (aTR 0.71 [0.59, 0.86]) interval. CONCLUSION: Balloon catheters, DVI, and DG/T for outpatient CR are comparable in terms of safety and effectiveness. When choosing between agents, consideration should be given to clinical findings, patient preference, and resource availability.