A Comparison of Synthetic Osmotic Dilators and Pharmacologic Agents for Cervical Ripening in Induction of Labor: A Systematic Review and Meta‐Analysis

Introduction Given the rising number of studies on synthetic osmotic dilators, there is a lack of comprehensive reviews for their use compared with other commonly used cervical ripening methods. This study aimed to examine the maternal and neonatal safety and efficacy in cervical ripening and labor induction using synthetic osmotic dilators compared with pharmacologic agents (prostaglandin E 1 , prostaglandin E 2 , oxytocin) for labor induction. Methods A systematic review and meta‐analysis of randomized controlled trials (RCTs) and cohort studies was conducted, using MEDLINE, Embase, CINAHL, and Cochrane Library databases search. Two reviewers independently screened studies and assessed the risk of bias with Risk of Bias 2 and Risk Of Bias In Nonrandomized Studies ‐ of Interventions tools. Relative risks (RRs) and mean differences (MDs) were calculated with 95% CIs. Results Eleven studies (8 RCTs, 3 cohort; 2355 participants) showed no statistically significant differences in safety outcomes between synthetic osmotic dilators and pharmacologic agents, including maternal infection (RR, 1.27), postpartum bleeding (RR, 0.87), neonatal infection (RR, 1.19), low Apgar scores (RR, 0.74), and admission to neonatal intensive care unit (RR, 1.06) (all P > .05). Efficacy outcomes were comparable for vaginal birth rates (RR, 0.98) and Bishop score changes (MD, 0.0) (both P > .05). Synthetic osmotic dilators reduced uterine hyperstimulation (RR, 0.45) and digestive symptoms (RR, 0.15) but required more artificial rupture of membrane (RR, 1.57) (all P < .05). Discussion Synthetic osmotic dilators are a safe, effective, and viable option for labor induction, reducing maternal risks of uterine hyperstimulation. These findings have implications for incorporating the clinical use of synthetic osmotic dilators for cervical ripening into international guidelines. As evidence supports their efficacy and safety, educating nurses and midwives in the use of synthetic osmotic dilators for labor induction is required.