Regimens of misoprostol with mifepristone for early medical abortion: a randomised trial

Abstract

Objective: To compare the efficacy, adverse effects and acceptability of the three most common misoprostol regimens used with mifepristone for medical abortion.

Design: Randomised nonblinded trial.

Setting: Three clinics associated with major research universities in Canada; two in major urban areas and one in a periurban area.

Population: Women of reproductive age.

Methods: Consenting women presenting for abortion services with gestations less than 56 days and who met inclusion criteria were given 200 mg mifepristone orally and then randomised into three misoprostol study groups: (group I) 400 micrograms of oral misoprostol, (group II) 600 micrograms of oral misoprostol, and (group III) 800 micrograms of vaginal misoprostol. Misoprostol was self-administered at home 24-48 hours following mifepristone, and participants were instructed to take a second similar misoprostol dose at 24 hours after the initial dose if bleeding was less than a normal menstrual period.

Main outcome measures: Successful abortion without surgery was 94.1%, with no significant differences across the three study groups (94.7% in group I, 93.4% in group II, and 94.3% in group III; P= 0.975).

Results: Efficacy and adverse effects did not differ significantly across the three study groups. Pain increased significantly across the study and the gestational age groups and was associated with lower acceptability.

Conclusions: There appears to be a range of safe and effective options for early medical abortion with mifepristone including a choice between oral and vaginal administration of misoprostol.