Mifepristone (RU 486) induces embryo expulsion in first trimester non-developing pregnancies: a prospective randomized trial

: This study was designed to investigate the use of oral mifepristone (RU 486) for the induction of natural expulsion of concepti in women with spontaneously interrupted pregnancy in the first trimester. It consisted of a double-blind placebo-controlled study of mifepristone (600 mg) against placebo. A total of 46 women consulting for interrupted pregnancy were diagnosed at ultrasound with no clinical sign of miscarriage. Measurements were made of the occurrence of natural expulsion, the frequency of complete expulsion, the need for subsequent surgical evacuation, analgesia and the need for transfusion. Natural expulsion occurred within 5 days in 82% of patients receiving mifepristone treatment versus 8% of placebo-treated patients (P < 0.001). All patients experienced bleeding after RU 486 and two needed emergency aspiration for haemorrhagic expulsion. The treatment failed in four patients, who underwent evacuation under local anaesthesia. In the control group, 19 patients underwent evacuation under local (n = 10) or general (n = 9) anaesthesia. It was concluded that a standard oral pilot dose of 600 mg of mifepristone induces natural expulsion in 82% of women with non-developing first trimester intrauterine pregnancies.