Early abortion with a single dose of the antiprogestin RU-486

RU-486 is a synthetic progesterone antagonist that is abortifacient in early pregnancy. This trial evaluated the effectiveness and safety of a single 600 mg oral dose given to 50 healthy women less than or equal to 49 days from their last menstrual period. Efficacy was inversely related to the initial beta-subunit of human chorionic gonadotropin level, ranging from 100% at less than 5000 mIU/ml to 81% at greater than 20,000 mIU/ml (p less than 0.05). Uterine bleeding was the most serious side effect. However, the mean change in the hemoglobin value 14 days after treatment was -0.4 gm/dl, and no patient required blood transfusion. This regimen appears to be simple, effective, and safe.