Trial of Labor after Three or More Previous Cesarean Sections: Systematic Review and Meta-Analysis of Observational Studies

Aims To assess the success rate and prevalence of maternal or neonatal complications in women undergoing a trial of labor after three or more (≥3) previous cesarean sections (CSs). Methods A systematic literature review and meta-analysis was conducted from inception to May 2022 in Medline, Scopus, ENBASE, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials and Reviews. Items detailing success rate and complications in women with a history of≥3 previous CSs were considered. Selected articles were evaluated for quality, heterogeneity, and publication bias. A pooled prevalence or odds ratio was calculated. Findings Twelve articles were included for a total of 540 women with a history of≥3 CSs, accounting for the 2% (CI 95% 1-4%) of the whole cohort of trial of labor. Our findings show a 0.67 (CI 95% 0.53-0.78) rate of successful vaginal delivery. A higher success rate was observed in women having a history of a prior vaginal delivery (0.90, CI 95% 0.77-0.96) and when prostaglandins, peridural anesthesia or oxytocin were allowed (respectively 0.73, CI 95% 0.62-0.83, 0,73, CI 95% 0.57-0.85 and 0.73, CI 95% 0.64-0.81). Uterine rupture rate was 0.01 (CI 95% 0.00-0.01). No cases of fetal asphyxia or maternal or neonatal death were registered. Conclusions The success rate and low frequency of severe complications observed seem to support a trial of labor in selected patients desiring a natural birth. However, a potential underestimation of serious maternal and neonatal complications should be considered in the decision-making process.