The Role of Lower Uterine Segment Thickness in Predicting Cesarean Scar Defects: Two-Dimensional Transvaginal Ultrasound Vs. Intraoperative Findings

Background and Aims: To evaluate the risk of uterine rupture during pregnancy, researchers use two-dimensional (2D) transvaginal ultrasound to assess lower uterine segment (LUS) thickness in the third trimester of pregnancy. This study aimed to compare the thickness of the LUS provided in a 2D transvaginal ultrasound with the findings during a cesarean section (C/S) of pregnant women with a history of previous C/S.Materials and Method: This cross-sectional study was performed on 40 pregnant women referred to Izadi Obstetrics and Gynecology Hospital in Qom. All the women underwent transvaginal ultrasound followed by C/S within a maximum of one week later. Also, an expert gynecologist classified LUS thickness into four grades in the operation room.Results: The mean age of women was 31.58 ± 4.56 years, and the mean thickness of the LUS was 2.17 ± 0.51 cm. Moreover, 57.5% of the women have graded I of LUS based on intraoperative findings. Results indicated that the mean thickness of the LUS measured by ultrasound significantly differed between the three grades detected by the gynecologist (P=0.04). However, there were no significant differences between maternal age, gestational age, parity, and time of last C/S among women with different LUS grades (P˃0.05). Transvaginal ultrasound could be helpful in evaluating the risk of scar dehiscence and uterine rupture among women with LUS grades I and II with a history of previous C/S.