Verifying the effectiveness of medical abortion; ultrasound versus hCG testing.

OBJECTIVES The combination of mifepristone and misoprostol is an established method for termination of pregnancy. However, there is no general agreement about how best to evaluate the treatment outcome. STUDY DESIGN In 217 women with an unwanted pregnancy below 49 days of amenorrhoea, ultrasound examination and serum hCG test were performed before treatment and at follow-up. RESULTS Treatment was successful in 98.2%. At follow-up their hCG dropped to a mean of 3% (S.D. 3) of initial levels and the endometrium measured a mean of 10 mm (S.D. 4). Interpretation of endometrium was difficult in some cases because of inhomogeneous structure. Using hCG was reliable in 98.5% of successful abortions. For ultrasound the corresponding figure was 89.8% for the cases with a confirmed intrauterine pregnancy before treatment but only 66% if all pregnancies were included. CONCLUSION Measuring serum hCG before treatment and at follow-up is more effective than ultrasound to confirm a successful medically induced abortion in early pregnancy.