Efficacy of mifepristone followed on the same day by misoprostol for early termination of pregnancy: report of a randomised trial.

OBJECTIVE: To examine the clinical efficacy of mifepristone 600 mg followed on the same day or two days later by misoprostol 400 microg orally in women undergoing medical termination of pregnancy whose pregnancies have a gestational age up to 49 days.

DESIGN: Prospective, randomised trial.

SETTING: Clinical research office.

PARTICIPANTS: Eighty-six women, requesting elective termination of a pregnancy which has a gestational age of < or = 49 days.

METHODS: After administration of mifepristone 600 mg, participants were randomised to take misoprostol six to eight hours later (Group 1) or 48 hours later (Group 2). Women returned for a follow up evaluation 24 +/- 1 hours after taking the misoprostol. Participants in Group 1 who had not aborted received a second dose of misoprostol to take 48 hours after the mifepristone. All women returned approximately two weeks after receiving mifepristone. If termination of pregnancy had still not occurred and the pregnancy was non-viable, the woman returned again in three weeks.

MAIN OUTCOME MEASURES: Rate of complete abortion 24 hours after administration of misoprostol.

RESULTS: At 24 hours after receiving misoprostol, 21/42 (50%, 95% CI 35%, 65%) women in Group I and 40/44 (91%, 95% CI 82%, 99%) women in Group 2 had complete abortions. By follow up two weeks later after the administration of mifepristone, 40/42 (95%, 95% CI 89%, 100%) women in Group 1 and 43/44 (98%, 95% CI 93%, 99%) women in Group 2 were known to have complete abortions. Nausea, vomiting or diarrhoea in women using the standard regimen (Group 2) occurred in 68%, 36%, and 20%, respectively.

CONCLUSIONS: After treatment with mifepristone 600 mg, administration of misoprostol 400 microg orally on the same day is not as effective at causing abortion within the first 24 hours compared with the standard time interval of 48 hours between medications.