Endometrial Thickness- a Practical Prospective Marker for the Risk of Surgical Intervention after RU486 Induced Abortion

Background: Medical termination of pregnancy [TOP] during the early fi rst trimester is commonly used. However, treatment failure which warrants surgical intervention occurs in small proportion of patients. Our objective was to examine the effec-tiveness and predictive value of sonographic measurement of endometrial thickness during a follow up visit after medical abortion as an accurate predictor of the necessity of curettage for completion of pregnancy termination. Methods: Women who opted for medical TOP where treated by single dose of RU486 followed by a single dose of misoprostol. Endometrial thickness was evaluated by transvaginal U.S. at 14 days after misoprostol tretament. The data was collected prospectively for this cohort study which includes all the women undergoing medical abortion in the fi rst seven weeks of gestation. Results: In 34.7 % of the patients the endometrial width was 11 mm on the follow-up visit. Surgical intervention was performed in 18 % of these patients, for a failure rate of the medical termination of pregnancy [TOP] of 6.25%, as com-pared with no failure rate in those with endometrium 11 mm, P 0.001. In the patients where the endometrium was 11–12 mm on follow-up, the failure rate was 5%, and if 12 mm the failure was 5.9%. In cases where the endometrium was 12–13 mm the failure rate was 27.3%, and if 13 mm the failure was 18.9%. When the endometrium was 13–14 m