Cesarean scar defect (CSD): prevalence, risk factors and clinical presentation: a cross-sectional observational study

The cesarean scar defect (CSD), or niche, is one of the emerging complications after cesarean section (CS), potentially leading to symptoms such as abnormal uterine bleeding, pelvic pain and secondary infertility. To determine the prevalence of CSD among women attending the outpatient clinic at Women’s Health Hospital, Assiut university, Egypt, and to identify the possible CSD-related symptoms and risk factors for CSD formation. This cross-sectional observational study included 234 women with a history of CS performed more than one year before recruitment, between June 2022 and December 2023. Participants underwent 2D transvaginal ultrasound to detect CSD, defined as an indentation of ≥ 2 mm depth at the CS scar site. Data collected encompassed demographic, obstetric, and variable symptoms and analyzed using univariate analysis and multiple logistic regression. A cross-sectional analysis revealed that 49.15% of participants (n = 115/234) have CSD. Stratified analysis of associated symptoms indicated a significantly higher incidence of postmenstrual spotting (73.9% vs. 26.1%, p < 0.001), dysmenorrhea (p = 0.007), and dyspareunia (p = 0.006) in women diagnosed with CSD compared to those without CSD. Furthermore, the median number of previous cesarean deliveries was significantly elevated in the CSD group (median 3 vs. 2, p = 0.004). Multivariate logistic regression modeling identified some independent risk factors for CSD, including the number of previous cesarean deliveries (Odds Ratio [OR] = 2.8, 95% Confidence Interval [CI] = 1.7–4.5, p < 0.001) and emergency CS (OR = 3.2, 95% CI = 1.8–5.8, p < 0.001). CSD is prevalent in nearly half of women with previous CS. It is significantly associated with symptoms such as postmenstrual spotting, dysmenorrhea, and dyspareunia. Key risk factors include multiple previous CS, and emergency cesarean deliveries. 2D TVUS is the first diagnostic tool used for detection and assessment of women with CSD.