Publications

A growing body of evidence suggests that the surgical technique for uterine closure influences uterine scar healing, but there is still no consensus about optimal uterine closure during cesarean delivery (CD). The aim of this systematic review and meta-analysis was to compare the effect of single- versus double-layer closure on the risk of uterine scar defect.MEDLINE, Scopus, ClinicalTrials.gov, the PROSPERO International Prospective Register of Systematic Reviews, EMBASE and the Cochrane Central Register of Controlled Trials were searched from inception of each database until May 2016. All randomized controlled trials (RCTs) evaluating the effect of single- versus double-layer closure at the time of low transverse cesarean on the risk of uterine scar defect were included. The primary outcome was the incidence of uterine scar defects detected on ultrasound. Secondary outcomes were residual myometrial thickness in mm, evaluated by ultrasound, and incidences of uterine dehiscence and uterine rupture at subsequent pregnancy. The summary measures were reported as relative risk (RR) or as mean differences (MD) with 95% confidence interval (CI). For this review the quality of the evidence was assessed using the GRADE approach.Nine RCTs (3,696 participants) were included in the meta-analysis. The overall risk of bias of the included trials was low. Statistically heterogeneity within the studies was low with no inconsistency in the primary and secondary outcomes. Women who received single-layer closure had a similar incidence of uterine scar defects (25.5% vs 43.0%; RR 0.77, 95% CI 0.36 to 1.64; 5 trials; 350 participants; low-quality of evidence) compared to women who received double-layer closure. Women who received single-layer closure had a significantly thinner residual myometrial thickness on ultrasound compared to double-layer closure (MD -2.19 mm, 95% CI -2.80 to -1.57; 4 trials; 374 participants; low-quality of evidence). No differences were found in incidence of uterine dehiscence (0.4% vs 0.2%; RR 1.34, 95% CI 0.24 to 4.82; 3 trials; 3,421 participants; low-quality of evidence) or uterine rupture in the subsequent pregnancy (0.1% vs 0.1%; RR 0.52, 95% CI 0.05 to 5.53; 1 trial; 3,234 participants; low-quality of evidence).Single- and double-layer closure of a cesarean uterine incision are associated with similar incidences of uterine scar defect, as well as incidences of uterine dehiscence and uterine rupture in a subsequent pregnancy.The quality of evidence was downgraded because of serious "imprecision." Outcomes were imprecise because studies included relatively few patients and few events and thus had wide CIs around the estimate of the effect and because the optimal information size was not reached. The quality of the evidence was also downgrade of another one level because of serious "indirectness" because of the different interventions. Therefore, the quality level of summary estimates was low as assessed by GRADE, indicating that the true effect may, or is even likely to, be substantially different from the estimate of the effect.