Background and Objectives: A cesarean scar defect (CSD), also referred to as a niche or isthmocele, is often detected incidentally during transvaginal sonography (TVS) and is typically asymptomatic. However, the exact prevalence of symptomatic niches remains unclear. This study aimed to evaluate the incidence of cesarean scar niches and identify potential risk factors in a prospectively gathered cohort of Egyptian women. Materials and Methods: The primary endpoint was to determine the incidence of isthmoceles after six months following a cesarean section (CS) and to investigate any associated symptoms and risk factors. The study included 420 women, divided into three groups: Group A included 140 women who had undergone their first CS, Group B included 140 women with a history of two CSs, and Group C consisted of 140 women with more than two prior CSs. Results: Niches were identified in 23.8% of the participants via TVS. The highest incidence was observed in women with more than two previous CSs (31.2%, 39/125), followed by those with two prior CSs (24.4%, 30/123), and the lowest was among women with one previous CS (16.3%, 22/135). Of the 91 women diagnosed with a CS niche, only 23 (25.27%) reported symptoms-most commonly postmenstrual spotting (7.7%) and dyspareunia (8.8%). Conclusions: The findings indicate that multiple cesarean deliveries, the uterine positioning (as assessed via TVS), a postpartum fever, breastfeeding, low post-cesarean platelet counts, and maternal anemia are contributing factors to the development of cesarean scar niches.
Keywords: cesarean scar defect; complications; isthmocele; niche; risk factors.