Objective To determine whether Cesarean scar defect (CSD) parameters assessed by transvaginal sonography (TVS) might affect the outcome of early termination of pregnancy (TOP) with mifepristone-misoprostol. Methods This was a retrospective review of 183 women with previous Cesarean delivery who received oral mifepristone and misoprostol for TOP. A successful TOP was defined by the absence of an intrauterine gestational sac, with no need for surgical intervention. CSD was diagnosed by TVS in the presence of a hypoechogenic indentation within the myometrium of the lower uterine segment at the site of a previous Cesarean incision. Women were analyzed in three subgroups according to size of defect (ratio of residual myometrial thickness over the defect to adjacent myometrial thickness <30%, 30%-70% and > 70%). Results Of the 183 women, 43 (23.5%) had failure of TOP. Fifty-nine (32.2%) had CSD detectable at TVS, and these women had a higher failure rate of TOP than did those without CSD (38.9% vs 16.1%; P = 0.001). CSD was associated significantly with failure of TOP (odds ratio, 3.32 (95% CI, 1.64-6.75)). The TOP failure rates in relation to defect size in the myometrial thickness ratio <30%, 30%-70% and > 70% subgroups were 57.1%, 25.0% and 18.2%, respectively. There was a linear trend in failure rate across these ratios (Cochran-Armitage trend test; P = 0.015). Conclusions Women with CSD are at increased risk of failed TOP. Women with a defect in which the residual myometrial thickness was <30% of the adjacent myometrial thickness tended to have a greater chance of failed TOP. CSD detected at TVS is of clinical relevance in counseling women with a history of Cesarean delivery who are considering TOP.
ASJC Scopus subject areas
- Obstetrics and Gynaecology
- Radiology Nuclear Medicine and imaging
- Radiological and Ultrasound Technology
- Reproductive Medicine