Ultrasonographic Evaluation of Lower Uterine Segment Thickness in Patients with Previous Caesarean Section

ObjectiveTo evaluate the lower uterine segment (LUS) thickness in women with previous caesarean section and to determine the critical thickness above which safe vaginal delivery is predictable. Methods A descriptive study of 200 pregnant women with a previous lower segment caesarean section (CS) was carried out. Transabdominal sonography (TAS) was used to evaluate the LUS thickness. In women who underwent CS sonographic findings were correlated with the intraoperative LUS appearance. The obstetric outcomes in patients with successful trial of vaginal delivery and those who delivered by CS were correlated with LUS thickness. Results In the study group, out of 129 women who were allowed for trial of vaginal delivery, 67 (52 %) had successful vaginal birth after caesarean section (VBAC) and 62 (42 %) women delivered by emergency CS. Elective CS was done in 71 cases (35.5 %). The mean LUS thicknesses among VBAC, emergency and elective CS group were 40.74mm, 3.60.8mm and 3.41.2mm respectively. The difference between the VBAC and caesarean groups was statistically significant (p=0.03 and 0.01 in association with emergency and elective CS respectively). Ultrasonographic LUS thickness assessment correlated significantly with intraoperative LUS appearance (p