Transvaginal Ultrasound evaluation of the Cesarean scar: relation between a niche and abnormal uterine bleeding

Introduction: Cesarean section (CS) is a critical lifesaving operation for both mother and child, and its use has increased dramatically over the last decade. Mirroring global trends, CS rates in Egypt have steadily increased, reaching 52% of all deliveries according to the most recent 2014 Egypt Demographic and Health Survey (EDHS) and representing more than a 100% increase in the CS rate since 2005. Aim of the study: To evaluate the relationship between the presence of a niche and abnormal uterine bleeding in women with a history of Cesarean section. Subjects and Methods: The current observational cross-sectional study was performed between October 2020 and May 2021. All women who had a Cesarean section performed in our hospital were asked to participate. 225 women were included and examined with transvaginal sonography (TVS) 6–12 months after the Cesarean section. The depth, volume, and residual myometrium were measured in the case of a niche. The shape was assessed according to a specified classification. Results: The prevalence of a niche on evaluation with TVS was 24.0%. Postmenstrual spotting was reported by 33.6% of women with a niche and 15.2% of women without a niche (P=0.002). The niche volume significantly differed between women with and without postmenstrual spotting (P=0.02). Most niches had a semicircular (50.4%) or triangular shape (31.6%). No significant relationship was identified between the body of the niche and postmenstrual spotting (P=0.19). Conclusions: Our results demonstrate that 24% of women with a history of Cesarean section have a niche when examined by TVS and that a niche is associated with postmenstrual spotting.