(809) Vaginal misoprostol versus vaginal dinoprostone for labor induction: Individual participant data meta-analysis of randomized trials

In this individual participant data meta-analysis, we identified randomised controlled trials comparing vaginal misoprostol to vaginal dinoprostone for IOL in women with a live singleton gestation. Ovid MEDLINE, Ovid Embase, Ovid Emcare, CINAHL Plus, Scopus, Cochrane Library of registered trials, WHO ICTRP and clinicaltrials.gov were searched from inception to March 2023. We approached the authors of each study to share individual-level data. Primary outcomes were vaginal birth and composites for adverse perinatal and maternal outcomes. For the main analysis, data were analysed by the intention-to-treat principle. The primary meta-analysis used two-stage random-effects models, and the sensitivity analysis used one-stage mixed models. This meta-analysis is registered with PROSPERO (CRD42022321378).

Results:

Ten out of 52 eligible trials provided individual participant data, of which two were excluded after concerns about data integrity. The eight trials (4,180 participants) compared low-dose vaginal misoprostol (n= 2,077) and dinoprostone (n=2,103) (Table 1). Compared to vaginal dinoprostone, low-dose vaginal misoprostol had a comparable rate of vaginal birth (77.4% vs 77.6 %, adjusted odds ratio (aOR) 0.95, 95% CI 0.80 to 1.13, p=0.51, I²=0%) and comparable composite adverse perinatal outcomes (11.8% vs 11.8%, aOR 0.96, 95% CI 0.74 to 1.25, p=0.74, I²=36%). Composite adverse maternal outcomes were significantly lower with low-dose vaginal misoprostol (10.4% vs 8.96%, aOR 0.80, 95% CI 0.65:0.98, p=0.04, I²=0.0%). Sensitivity analysis for the primary outcomes revealed similar findings.

Conclusion:

Low-dose vaginal misoprostol and vaginal dinoprostone for IOL are comparable in terms of effectiveness and perinatal safety. However, low-dose vaginal misoprostol is likely to lead to a lower rate of composite adverse maternal outcomes than vaginal dinoprostone.