Balloon catheter plus concurrent vaginal misoprostol versus vaginal misoprostol alone for cervical ripening in induction of labor: A systematic review and an individual participant data meta-analysis of randomized controlled trials.

backgroundCervical ripening in labor induction using a combination of methods is gaining popularity, but the effectiveness and safety of this approach are not clear. The assessment of study trustworthiness has recently been raised for evidence synthesis.

objectiveTo compare the effectiveness, perinatal and maternal safety of cervical ripening in the induction of labor (IOL) using a balloon catheter with concurrent low-dose vaginal misoprostol (combined group) versus low-dose vaginal misoprostol alone. SEARCH STRATEGY: MEDLINE, Embase, Emcare, Scopus, Cochrane Library, WHO ICTRP and clinicaltrials.gov. SELECTION CRITERIA: Randomized controlled trials (RCTs), viable singleton gestation, no language restrictions, published and unpublished data. DATA COLLECTION AND ANALYSIS: A systematic search, screening for trustworthiness and study quality, and an individual participant data (IPD) meta-analysis were conducted. MAIN

resultsA total of eight of 22 (36.4%) trials provided individual participant data, of which three (604 participants) were excluded due to trustworthiness concerns after data checking. A total of 13 of 22 trials (59.1%) were identified as "not meeting trustworthiness criteria." This individual participant data meta-analysis included five trials (649 participants): two had prospective, another two had retrospective trial registrations, and one trial was unregistered. Vaginal delivery rate (adjusted odds ratio [aOR] 0.97, 95% confidence interval [CI]: 0.30; 3.12, very low certainty of evidence as downgraded due to imprecision, inconsistency and data completeness), composite adverse perinatal (aOR 0.88, 95% CI: 0.62; 1.24, very low certainty of evidence as downgraded due to imprecision, inconsistency and data completeness) and maternal outcomes (aOR 0.70, 95% CI: 0.33; 1.50, very low certainty of evidence as downgraded due to imprecision, inconsistency and data completeness) were comparable between the two groups in the individual participant data meta-analysis. Women in the combined group reported significantly less uterine hyperstimulation (aOR 0.20, 95% CI: 0.10; 0.41) and less meconium-stained liquor (aOR 0.23, 95% CI 0.07; 0.77). Based on aggregate data from eight trials meeting trustworthiness criteria (IPD and non-IPD), combined methods had an OR of 1.07 (95% CI: 0.68; 1.68) for vaginal delivery. In comparison, data from 13 trials not meeting trustworthiness criteria (IPD and non-IPD) showed an OR of 1.25 (95% CI: 0.88; 1.77) for vaginal birth.

conclusionsBased on trustworthy data, the current evidence does not suggest that one method is superior to the other for the effectiveness of the combined balloon catheter with concurrent low-dose vaginal misoprostol versus low-dose vaginal misoprostol alone. At present, we are uncertain about the safety of using the combined method due to low data retrieval and trustworthiness concerns among the underlying trials. The results could slightly favor the combined method due to reduced hyperstimulation and meconium-stained liquor.