Ultrasound evaluation of Cesarean scar after single- and double-layer uterotomy closure: a cohort study

Objectives: To compare residual myometrial thickness (RMT) and size of the Cesarean scar defect after single- and double-layer uterotomy closure following first elective Cesarean section.

Methods: A retrospective cohort study was conducted in 149 women at least 6 months after an uncomplicated, elective Cesarean delivery. Two-dimensional transvaginal ultrasonographic measures of RMT, scar defect depth, width and length and myometrial thickness adjacent to the scar were compared in 68 women with single-layer and 81 women with double-layer closure delivered before and after, respectively, a change in the surgical procedure. Outcomes between the two groups were compared.

Results: Median RMT was 5.8 (interquartile range (IQR), 4.1-7.8) mm in women with double-layer closure vs 4.6 (IQR, 3.4-6.5) mm in those with single-layer closure (P = 0.04). Scar defect length was greater in women with single-layer closure (median, 6.8 (IQR, 4.4-8.5) mm) than in those with double-layer closure (median, 5.6 (IQR, 3.9-6.8) mm) (P = 0.01). Measurements of defect depth and width, and the proportion of scars with RMT < 2.3 mm were similar in the two groups.

Conclusions: RMT was greater and defect length, but not defect depth and width, was smaller following double-layer compared with single-layer closure, which may indicate some limited benefit of double-layer closure following first elective Cesarean section.