Uterine externalization versus in situ repair of hysterotomy during cesarean delivery: a systematic review, equivalence meta-analysis, and trial sequential analysis

Uterine positioning during hysterotomy repair is controversial, with both in situ and externalized approaches commonly performed. Despite many published trials, clinical equipoise remains. This meta-analysis and trial sequential analysis (TSA) summarizes studies comparing both techniques.A systemic search for randomized controlled trials comparing in situ with externalized hysterotomy repair during cesarean delivery was performed. The primary outcomes were estimated blood loss (EBL) and surgical duration. Secondary outcomes were need for blood transfusion, incidence of endometritis, hospital length of stay, intra-operative hypotension, return of bowel function, intra-operative vomiting, intra-operative pain, and need for postoperative analgesia. Cochrane methodology was used to assess risk of bias. Data are presented as mean difference/standardized mean difference or odds ratio/risk difference with 95% confidence intervals (CI).Nineteen studies enrolling 20 739 patients were included. Estimated blood loss and surgical duration were equivalent between methods, with TSA confirming adequate information size for surgical duration but not EBL. In situ repair was associated with faster return of bowel function (MD -0.76 days; 95% CI -1.36 to -0.15; P=0.01) and a reduction in need for breakthrough postoperative analgesia (OR 0.44; 95% CI 0.28 to 0.68; P <0.01).This analysis revealed equivalence between methods for EBL and surgical duration. While the small reduction in EBL with externalized repair was not clinically or statistically significant, TSA analysis revealed an unmet information size, suggesting a potentially inconclusive result. In situ repair may be associated with less breakthrough postoperative analgesia requirement and faster return of bowel function.