Original research
Comparison of abortions induced by methotrexate or mifepristone followed by misoprostol

https://doi.org/10.1016/S0029-7844(02)01944-0Get rights and content

Abstract

OBJECTIVE:

To compare the effectiveness, side effects, and acceptability of medical abortions induced by methotrexate and misoprostol with abortions induced by mifepristone and misoprostol.

METHODS:

This was a multicenter, randomized, nonblinded, controlled trial comparing 50 mg/m2 of methotrexate followed 4–6 days later by 800 μg of vaginal misoprostol with 600 mg of oral mifepristone followed 36–48 hours by 400 μg of oral misoprostol.

RESULTS:

There were 518 women in the methotrexate group and 524 women in the mifepristone group. In the methotrexate group, 21 women required suction curretage, two for continuing pregnancy, eight because of physician request (usually for excessive bleeding), and 11 because of patient request. In the mifepristone group, 22 women needed surgical termination, 17 because of physician request, and five because of patient request. By day 8, only 386 (74.5%) in the methotrexate group had completed the abortion compared with 474 (90.5%) in the mifepristone group, and the mean number of days from beginning to completion was 7.1 for methotrexate and 3.3 for mifepristone (P ≤ .001). There were no differences in complications, and side effects were similar. Acceptance was slightly higher with mifepristone (88.0%) than with methotrexate (83.2%).

CONCLUSION:

Abortions induced with mifepristone completed faster than those induced with methotrexate, but the overall success rates, side effects, and complications were similar. Acceptance rates were slightly higher with mifepristone than methotrexate (P = .03).

Section snippets

Materials and methods

This was a multicenter, randomized, nonblinded, controlled trial comparing medical abortions induced by mifepristone followed by misoprostol with those induced by methotrexate followed by misoprostol with respect to completed abortion without need for surgery as demonstrated by endovaginal scan. Other outcome measures included the percentage of abortions completed by day 8, complications, side effects, and patient acceptability. This study was approved by the Clinical Research Ethics Board of

Results

There were 1411 women screened for this study; 1146 were found eligible and 80 declined, resulting in 1066 being randomized. Twenty-four women dropped out after randomization but before treatment leaving 1042 who received medications. There were 518 women in the methotrexate group and 524 in the mifepristone group. There were no significant differences in the two groups with respect to maternal age, gestational age, ethnicity, or obstetric history (Table 1).

Three women were lost to follow-up.

Discussion

The most important difference between the two drug regimens was the speed of action. The bleeding started sooner after the misoprostol in the mifepristone group (3.0 hours) compared with the methotrexate group (4.6 hours). The actual day of abortion was earlier (mean 3.3 days compared with 7.1 days, median 3 days compared with 5 days). This is expected as the misoprostol was administered more quickly after the mifepristone than the methotrexate (at least 36 hours compared with at least 96

References (38)

Cited by (45)

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    While methotrexate has been used in the past in medication abortion regimens, its use has been largely supplanted by mifepristone and misoprostol regimens, which have a much better toxicity profile and higher efficacy rates. Methotrexate regimens have similar efficacy to misoprostol alone, as methotrexate has limited activity as an abortifacient-it simply creates a non-viable gestion [26]. A common regimen is 50 mg/m2 intramuscular methotrexate followed by 800 μg of misoprostol vaginally 72 h later.

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  • Medications Used in Evidence-Based Regimens for Medical Abortion: An Overview

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    This combined effect may explain the short duration of the MA process and rapid onset of expulsion of the pregnancy after MISO administration in MIFE/MISO regimens. As shown in a Canadian RCT,5 abortions induced with use of MIFE/MISO were completed faster than those induced with use of MTX/MISO, although the overall success rates at 36 days after induction were similar. By the eighth day after the first medication (MIFE or MTX), 90.5% of women in the MIFE group (n = 474) had aborted completely compared with 74.5% of women in the MTX group (n = 386); the mean number of days from beginning to completion was 3.3 days for MIFE and 7.1 days for MTX (P < 0.001).5

  • Medical Abortion

    2016, Journal of Obstetrics and Gynaecology Canada
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    One major difference between these MTX/MISO and MIFE/MISO regimens is the longer delay to obtain complete abortion. A Canadian randomized, controlled trial of 1042 women demonstrated completion by day 8 in 75.5% in the MTX/MISO group compared with 90.5% in the MIFE/MISO group, and the mean number of days to completion was 7.1 days and 3.3 days, respectively.142 In a large multicenter trial, 69.7%, 87.7%, and 91.7% using MTX/MISO completed their abortion by 14, 28, and 35 days, respectively.

  • Comparison of remote and in-clinic follow-up after methotrexate/misoprostol abortion

    2015, Contraception
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    Where mifepristone is unavailable, as in Canada, methotrexate with misoprostol is an alternative. Although shown to be as effective as mifepristone for abortions up to 49 days gestation, the process with methotrexate is longer and less predictable [1,2]. Methotrexate is highly teratogenic [3], raising concerns about the need for follow-up to ensure pregnancy termination.

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This study was funded by the Province of British Columbia.

We gratefully acknowledge the assistance of Drs. Ludek Podhradsky, Inna Tcherenkova, and Jonathan Berkowitz.

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