Vaginal Misoprostol Compared to Vaginal Dinoprostone for Induction of Labour: A Systematic Review and Meta-Analysis.

Abstract

Induction of labour is a common intervention. The prostaglandin dinoprostone is often used, but there is increasing evidence that misoprostol may be more effective without compromising safety. This review compares the efficacy and safety of vaginal misoprostol and vaginal dinoprostone. Electronic databases were searched for randomised controlled trials comparing singleton, term inductions with vaginal dinoprostone or vaginal misoprostol. The primary outcome was vaginal births within 24 h. Secondary outcomes included induction to birth interval, mode of birth, oxytocin augmentation, uterine hyperstimulation, fetal distress and adverse maternal and neonatal outcomes. A sub-group analysis by misoprostol dosage (25 and ≥ 50 μg) was planned. A random effects meta-analysis was performed and risk of bias assessed using Cochrane Risk of Bias 2 tool. 44 papers reported 7040 participants induced with vaginal misoprostol and 6604 with vaginal dinoprostone. Participants given vaginal misoprostol were 48% (OR 1.48 95% CI 1.20, 1.84) more likely to achieve vaginal birth within 24 h, although heterogeneity was high. The rates of caesarean section, and adverse maternal or neonatal outcomes were comparable. In the vaginal misoprostol group, fewer patients required oxytocin (OR 0.51 95% CI 0.40, 0.65) and time to birth was reduced (-230 min (95% CI -286 to -175, I² 57.6%)). These findings were consistent in the subgroup analysis, although uterine hyperstimulation with fetal heart rate changes was reduced in the 25-μg group. Vaginal misoprostol is more effective for achieving vaginal birth in 24 h, reducing time to birth and oxytocin use when compared to vaginal dinoprostone. It does not seem to increase caesarean birth and has a similar side-effect profile. At lower doses (25-μg), it is likely to be similarly effective with a lower incidence of uterine hyperstimulation. This information can be used to support discussions around choice of induction agent.