Comparison between Intraoperative and Ultrasound Determined Cesarean Scar Thickness after Elective Cesarean Sections and Unplanned Cesarean Sections in Subsequent Term Pregnancies

Abstract

esarean section is currently the most common obstetric procedure throughout the world. The number of cesarean deliveries increased worldwide in the past 25 years. Cesarean scar evaluation becomes important nowadays due to increased incidence of delayed scar complications. Reported scar complications included scar defect (niche), abnormal healing, abnormal vascularization, liability for rupture and placental invasion in subsequent pregnancy. Assessment of cesarean scar is important as non-healthy or poor-healed scar are associated with some complication such as chronic pelvic pain, dyspareunia, and abnormal bleeding. Moreover these poor-healed scars may predispose to preterm labour and uterine dehiscence or rupture in subsequent pregnancy. Cesarean scar defects are diagnosed by radiologic, ultrasonographic, endoscopic and histologic methods. Ultrasound estimation of lower uterine segment provides a fairly simple and non-invasive method for prediction of scar dehiscence/rupture. The successful outcome of TOLAC depends on the scar of previous CS, which is directly related to its thickness. Evaluation of thickness of LUS has been found to be a potential factor for predicting scar dehiscence. The risk of scar dehiscence/rupture has been directly related to the thinning of LUS. However, there is controversy over the thickness of LUS above which TOLAC can be offered safely.