Comparison of Uterine Closure Techniques and Their Association With Cesarean Scar Defect Development: A Randomized Controlled Trial

Background: To compare three uterine closure techniques regarding postoperative residual myometrial thickness (RMT) and their association with cesarean scar defect (CSD) formation. Methods: A prospective, assessor-blinded, randomized controlled trial (RCT) was conducted in 48 nulliparous women undergoing primary cesarean delivery. Participants were randomly assigned to one of three groups: Group 1, double-layer continuous non-locking suturing with endometrial inclusion and an imbricating second layer; Group 2, double-layer continuous non-locking suturing without endometrial inclusion and an imbricating second layer; Group 3, double-layer continuous suturing with the first layer incorporating the endometrium and deep myometrium and the second layer including the remaining myometrium. Transvaginal ultrasonography was performed 6 months postoperatively to measure RMT and evaluate the presence of CSDs. The study was powered to detect differences in RMT rather than CSD incidence. Results: No significant differences in preoperative and postoperative changes in visual analog scale (VAS) scores were observed among the groups. Mean RMT was comparable across the three groups (7.1 ± 2.2 mm, 7.3 ± 1.6 mm, and 7.4 ± 1.8 mm, respectively; p = 0.920). CSD was identified in 7.1%, 21.4%, and 6.7% of patients in Groups 1, 2, and 3, respectively (overall incidence, 11.6%; p = 0.404). Conclusion: No significant differences in postoperative RMT were observed among the uterine closure techniques evaluated. Larger prospective studies powered to detect differences in CSD outcomes are warranted. Clinical Trial Registration: The study was registered to https://clinicaltrials.gov/ with an ID of NCT05100147 (https://clinicaltrials.gov/study/NCT05100147?cond=NCT05100147%20&rank=1).