Prediction of cesarean section scar dehiscence before delivery using three-dimensional transabdominal ultrasonography

Abstract

Objective This study aimed to evaluate the efficacy of three-dimensional (3D) ultrasonography in the prediction of cesarean scar dehiscence in pregnant patients at term and to compare the outcome of measurement with the intraoperative visual assessment of the scar. Design This was a prospective study. Patients and methods Seventy pregnant women with a history of a previous cesarean section attending Benha University Hospital were included in this study. All participants underwent a 3D transabdominal scan at third trimester and the data were recorded. We measured the lower segment thickness from the muscularis and mucosa of the bladder on the outer side to the chorioamniotic membrane on the inner side, with the myometrium in between, and hence, depending on a three-layered pattern. This was compared with the pregnancy outcome and the intraoperative scar condition. The data were then statistically analyzed. Results The mean scar thickness as measured by 3D transabdominal sonography in the third trimester was 4.63 ± 0.85 mm. The best cut-off level for predicting uterine scar defects was less than or equal to 2.75 mm (highest diagnostic accuracy) with sensitivity 25%, specificity 100%, positive predictive value 100%, and negative predictive value 95%. Conclusion The current study suggests that prenatal 3D US examination determining the degree of lower uterine segment thinning in patients with previous cesarean delivery provides an additional element for assessing the risk of uterine rupture and may increase safe management of trial of labor.