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

Abstract

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.

PIP: At the Hopital A. Beclere in Clamart, France, physicians randomly allocated 46 women with a non-developing, intrauterine pregnancy to either a group receiving a single dose of RU-486 (3 tablets = 600 mg) or a group receiving three tablets of a placebo so they could determine whether RU-486 without an associated prostaglandin could facilitate natural expulsion of the embryo in non-developing first trimester pregnancies with no clinical sign of spontaneous abortion. At the end of five days, natural expulsion was much higher in the RU-486 group than the placebo group (82% vs. 8%; p 0.001). The five-day course for spontaneous expulsion was acceptable for patients and physicians. All RU-486 patients experienced bleeding, compared to only 24% of placebo patients (p 0.01). Two RU-486 patients experienced frank hemorrhage on days two and three of treatment and required emergency aspiration. The 10% hemorrhaging rate equals that of the observed rate of natural expulsion, suggesting that hemorrhaging was likely due to natural expulsion rather than RU-486. RU-486 failed to induce natural expulsion in four women (18%) who then underwent evacuation under local anesthesia. These women had higher initial progesterone and human chorionic gonadotropin (HCG) levels and shorter amenorrhea (50-70 days) than those who did not experience treatment failure, suggesting a recent ending of trophoblastic activity. Dilation and aspiration were performed on 19 controls under local (10) or general (9) anesthesia. Between day one and day five, the total reduction in progesterone levels and in HCG levels was much greater in the RU-486 group than controls. These findings indicate that a single 600 mg dose of RU-486 is a sound way of managing non-developing pregnancies diagnosed during the first trimester.