Cephalad-caudad versus transverse blunt expansion of the low transverse hysterotomy during cesarean delivery decreases maternal morbidity: a meta-analysis

Abstract

Objective: Cesarean delivery is the most prevalent surgical procedure worldwide, reaching approximately 29.7 million cases in 2015. It is directly associated with an increased risk of maternal and neonatal morbidity rates in the absence of malpresentation. Several techniques have been investigated, and there is evidence that cephalad-caudad expansion of the uterine incision might be associated with improved maternal outcomes compared with traditional transverse blunt expansion. The purpose of this meta-analysis was to evaluate the impact of cephalad-caudad expansion on adverse maternal outcomes, including intraoperative blood loss, risk of uterine vessel injury, and tearing of the lower uterine segment.

Data sources: We searched Medline, Scopus, the Cochrane Central Register of Controlled Trials, Google Scholar, and Clinicaltrials.gov databases from inception to January 2021.

Study eligibility criteria: Randomized controlled trials that assessed the impact of the cephalad-caudad blunt expansion of the low transverse uterine incision during cesarean delivery rather than those of transverse blunt expansion were selected for inclusion.

Methods: Effect sizes were calculated with the Hartung-Knapp-Sidik-Jonkman random-effects model in R. Trial sequential analysis was performed to evaluate the adequacy of sample sizes.

Results: Cephalad-caudad blunt expansion of the uterine incision was associated with a lower prevalence of unintended incision extension (relative risk, 0.62; 95% confidence interval, 0.45-0.86) and uterine vessel injury (relative risk, 0.55; 95% confidence interval 0.41-0.73). However, these complications were not accompanied by the increased need for additional suture placement (relative risk, 0.62; 95% confidence interval, 0.31-4.12) or transfusion rates (relative risk, 0.75; 95% confidence interval, 0.28-2.03). Similarly, the intraoperative duration was comparable with cases treated with transverse blunt expansion (mean difference = -0.45 minutes; 95% confidence interval -2.12 to 1.21) and the risk of intentional incision extension in the form of an inverted T (relative risk, 0.38; 95% confidence interval, 0.09-1.52). Trial sequential analysis revealed that the required sample size was reached in the unintended incision extension and uterine vessel injury outcomes.

Conclusion: The findings of our study suggested that cephalad-caudad blunt expansion of the uterine incision is superior to transverse expansion in terms of reducing unintended incision extension and uterine vessel injury.

Keywords: blood transfusion; cesarean delivery; complications; hemorrhage; meta-analysis; obstetrical labor; prediction intervals; trial sequential analysis.