Comparison of two doses of mifepristone in combination with misoprostol for early medical abortion: a randomised trial

Citation
Ym. Wu et al., Comparison of two doses of mifepristone in combination with misoprostol for early medical abortion: a randomised trial, BR J OBST G, 107(4), 2000, pp. 524-530
Citations number
12
Categorie Soggetti
Reproductive Medicine","da verificare
Journal title
BRITISH JOURNAL OF OBSTETRICS AND GYNAECOLOGY
ISSN journal
14700328 → ACNP
Volume
107
Issue
4
Year of publication
2000
Pages
524 - 530
Database
ISI
SICI code
1470-0328(200004)107:4<524:COTDOM>2.0.ZU;2-Z
Abstract
Objectives To compare the efficacy of two different regimens of mifepriston e followed by misoprostol for medical abortion in women with menstrual dela y of less than or equal to 35 days. Design Double-blind, randomised controlled trial. Setting Seventeen centres internationally. Participants We enrolled 1589 healthy pregnant women with menstrual delay o f less than or equal to 35 days who were requesting nonsurgical abortion. Interventions Within gestational age strata, we randomly assigned women to receive a single oral dose of mifepristone, either 200 mg or 600 mg, follow ed in 48 h by misoprostol 400 mu g by mouth. We concealed the allocation as signments from investigators and participants and maintained double-blindin g throughout the study. Main outcome measures Complete abortion was the principal outcome measure. We also compared rates of side effects such as abdominal pain. Results The complete abortion rate with the lower dose of mifepristone was similar to that with the higher dose (89.3% vs 88.1%) The crude relative ri sk of failure to achieve complete abortion with the 200 mg dose compared wi th the 600 mg dose was 0.9 (95% CI 0.7 to 1.2). The likelihood of complete abortion was inversely related to gestational age, although this finding is exploratory in nature. Among failures the percentage of women with continu ing pregnancies increased from 1.4% at menstrual delay of two weeks or less to 9.0% when the delay was 4-5 weeks. Low efficacy led to stopping enrolme nt at 29 to 35 days' menstrual delay. Stopping criteria were also met at co mpletion of the study in the group with 22-28 days' menstrual delay. No sig nificant differences emerged in the frequency of side effects between the t wo mifepristone groups. Conclusions Both regimens had similar efficacy. Women with a menstrual dela y of four to five weeks had twice the risk of failure to abort compared wit h those who received treatment within two weeks of the expected menses. The efficacy of the mifepristone-prostaglandin regimen was not reduced by decr easing the dose of mifepristone from 600 mg to 200 mg. The regimens of 600 mg or 200 mg of mifepristone, followed by a single oral dose of misoprostol 400 mu g 48 hours later, were not sufficiently efficient in inducing abort ion when the menstrual delay was > 21 days.