Evaluation of the Cesarean Scar Defect by Ultrasound and Its Association with Gynecological Symptoms: A Prospective Observational Study

Background: With the increasing prevalence of cesarean deliveries, concerns regarding long-term complications, particularly cesarean scar defects (CSD), also known as uterine niches, have grown.This study aimed to evaluate CSD using transvaginal sonography (TVS) and explore how these defects relate to gynecological symptoms such as abnormal bleeding, pelvic discomfort, and urinary issues.Materials and methods: This study was conducted at a tertiary care center from February 2023 to January 2025.A total of 152 women with a history of cesarean delivery were followed up at 6 weeks and 6 months postpartum.Using standardized TVS protocols, we measured niche dimensions and residual myometrial thickness (RMT) and correlated these findings with common gynecological complaints.Results: Uterine niches were identified in 64.5% of the women.Those with ≥2 lower-segment cesarean sections (LSCSs) had significantly deeper niches (7.10 ± 1.81 mm, p = 0.05) and thinner RMT (4.86 ± 1.85 mm, p = 0.03).Retroflexed uteri were associated with wider niches (7.35 ± 2.10 mm, p = 0.03) and thinner RMT (5.33 ± 1.57 mm, p = 0.02).Symptoms, including postmenstrual spotting, dyspareunia, chronic pelvic pain, and painful micturition, were significantly related to niche morphology (all p < 0.05).Receiver operating characteristic (ROC) analysis demonstrated a strong predictive value for chronic pelvic pain [area under the curve (AUC) = 0.864], postmenstrual spotting (AUC = 0.836), and painful micturition (AUC = 0.783).Multivariate analysis confirmed that age, multiple LSCS, retroflexed uterus, and postmenstrual spotting were independent predictors of CSD.Conclusion: Cesarean scar defects are highly prevalent and significantly associated with postmenstrual bleeding, dyspareunia, chronic pelvic pain, and painful micturition.Transvaginal sonography is crucial for evaluation, and RMT is a key predictor of successful outcomes.