Low uterine segment thickness in the prediction of cesarean delivery after induction of labor.

The aim of our study was to examine the relationship between lower uterine segment (LUS) thickness and cesarean delivery (CD) and compare the capacity two measurement methods of LUS thickness in the prediction of successful induction of labor (IOL). This was a prospective cross-sectional study of consecutive pregnancies undergoing IOL between 2022 and 2023. The inclusion criteria were women with singleton pregnancies with cephalic presentation whose Bishop scores were below six undergoing IOL after 37 weeks of gestation. Patients with a history of CD, fetal anomalies, multiple gestations, and any contraindication to vaginal delivery were excluded from the study group. A total of 124 pregnant women were included in the study. LUS (10.13 ± 1.98 mm vs. 7.07 ± 1.66 mm, p<0.001) and myometrial LUS (MLUS) (5.63 ± 1.48 mm vs. 4.10 ± 1.22 mm, p<0.001) in the CD group were significantly higher than in the non-CD group. In the logistic regression analyses, significant independent effects of height (OR:0.88, 95 % CI: 0.79-0.98) and LUS (OR:2.71, 95 % CI: 1.66-4.43) values were observed in the prediction of CD. In the ROC analysis, both LUS (AUC 0.882, p<0.001) and MLUS (AUC 0.756, p<0.001) significantly predicted CD with an optimal cut-off value of 9.8 mm (75.0 % sensitivity, 92.6 % specificity) for LUS, and 5.1 mm (68.8 % sensitivity, 82.4 % specificity) for MLUS. Ultrasonographic evaluation of LUS before IOL is a promising ultrasound parameter to predict CD. Although LUS and MLUS thickness measurements can be used to predict CD, LUS thickness has better sensitivity and specificity compared to MLUS thickness.