Sonographic appearance of the uterine cavity following administration of mifepristone and misoprostol for termination of pregnancy

Purpose. To describe the sonographic appearance of the uterine cavity in women after administration of mifepristone and misoprostol for termination of pregnancy. Methods. Thirty-six women treated with mifepristone 600 mg followed by misoprostol 400 μg 2 days later for termination of pregnancy were the subjects of the study. Gestational age as calculated from the last menstrual period was ≤49 days. Pretreatment sonographic parameters, including gestational sac size and crown-rump length, were measured. The sonographic appearance of the uterine cavity was recorded and documented 6 hours (T-1) and 14 days (T-2) after administration of misoprostol. Results. The mean menstrual age of the patients was 42 days (range 31-49 days). The mean gestational age according to crown-rump length was 43 days (range 40-48 days). Sonographic examination performed at T-1 revealed 23 patients (62.9%) with a well-defined echogenic mass located in the uterine cavity, 2 patients (5.5%) with an intrauterine sac containing a nonviable embryo, and 11 patients (30.5%) with an endometrium thickness of 7-14 mm with no evidence of intrauterine contents. Doppler flow signals were detected in 15 of the 23 patients (65.2%) with an echogenic intrauterine mass. Sonographic examination performed at T-2 revealed 19 patients (52.8%) with a persistent echogenic intrauterine mass; Doppler flow could be detected in 15 of these patients (78.9%). Dilatation and curettage was required in 2 patients (5.6%) due to failure of treatment; all others regained normal menses. Conclusions. An intrauterine echogenic mass with well-defined borders, with or without Doppler flow signals, can be detected 2 weeks after administration of mifepristone and misoprostol for termination of pregnancy. Because most of the women in our study regained normal menses without further surgical intervention, this finding could indicate remnants of trophoblastic tissue evacuated spontaneously from the uterine cavity. Therefore, dilatation and curettage should be avoided in these cases, unless clinical symptoms or signs necessitate surgical intervention.