Comparison of the primary cesarean hysterotomy scars after single- and double-layer interrupted closure.

Introduction: It is unclear whether hysterotomy closure techniques can affect niche development. Therefore, this study aimed to analyze the effect of single-layer and double-layer interrupted closures of hysterotomy incisions during primary cesarean section on the formation of uterine niches.

Material And Methods: A prospective cohort study of women undergoing primary cesarean section was performed between June 2011 and July 2014. Saline contrast sonohysterography was used to measure the niche depth and residual myometrium. The ratio of the niche depth to the sum of the niche depth and residual myometrium thickness (niche ratio) was calculated.

Results: Niches were identified in 14/58 (24.1%) women with single-layer sutures and 55/209 (26.3%) women with double-layer sutures (p = 0.74). Single-layer closure was associated with more than a five-fold increase in the odds of a niche ratio ≥0.4 (odds ratio 5.59; 95% CI 1.71-18.28).

Conclusion: Single-layer closure may be associated with an increased risk of larger niches (niche ratio ≥0.4), although it may not increase the overall frequency of niche formation.