Relation between Position of the Uterus (Anteversion or Retroversion Flexion) and Degree of Cesarean Scar Niche: Cross-sectional Study

Background: In recent decades, the Cesarean section rate has been significantly rising, leading to a surge in complications associated with surgical scars, notably the development of cesarean scar niche (CSN). Exploring the symptoms, correlations, and risk factors associated with its occurrence has marked now as a main point of interest. Objectives: The aim of the study was to determine the association between the size of caesarean scar niche and uterine position in childbearing women. Methods: This cross-sectional study was conducted at tertiary care hospital at gynecological outpatient clinic - Ain Shams University Maternity Hospital (ASUMH) from October 2023 till June 2024 and performed on to-tal 86 women with a history of cesarean section. All of them were subjected to full history taking, and sono-graphic assessment of caesarean scar niche (width, depth, length, residual myometrial thickness (RMT) overlying the defect, and the adjacent myometrial thickness fundal to the defect), and the uterine position was classified as anteverted or retroverted, using transvaginal ultrasound with inclusion and exclusion criteria.Results: The prevalence of large CSN was 40.7% and that was significantly higher in RVF uterus (80%) compared to AVF uterus (28.8%) (P= 0.001). This indicates a 2.78-fold increased risk of a large CSN in RVF uterus. Additionally, there was a statistically significant highest mean value of ratio between depth and adjacent myometrial thickness, the width, and depth of CSN in RVF group compared to AVF group. (P= 0.001, 0.038, and 0.001 respectively). On the other hand, the mean value of RMT was significantly lower in the RVF group compared to the AVF group (P= 0.013). However, no statistically significant differences were observed in the number of CSN, its length, or the adjacent myometrium between the two groups. In terms of clinical symptoms there was a statistically significant higher prevalence of severe chronic pelvic pain in large CSN group (8.6%) compared to small CSN group (3.9%) (P= 0.022). However, there was no statistically significant difference between large and small CSN in post-menstrual spotting, AUB, dysmenorrhea, dyspareunia and secondary infertility.Conclusion: The retroverted position of the uterus has been associated with an increased risk of developing more significant and larger CSN in terms of depth and width. This could be due to the altered angle and mechanical stress on the cesarean scar site, potentially affecting healing. These results may help in the counseling of patients regarding their subsequent pregnancies when a decision involving a Cesarean section is being considered.