Accounting for time: insights from a life-table analysis of the efficacy of medical abortion

A systematic review of more than one dose of misoprostol after mifepristone for abortion up to 10 weeks of gestation

OBJECTIVES

This review aimed to assess the effectiveness, acceptability and safety of regimens that include mifepristone and multiple misoprostol doses for abortion up to 10 weeks of gestation.

METHODS

We searched MEDLINE and reference lists for English-language reports (published between January 1990 and September 2005) of trials evaluating a medication abortion regimen consisting of mifepristone and multiple doses of misoprostol. Eligible trials had to either be restricted to women with less than 10 weeks' gestation or report stratified results that allowed the extraction of data for this subset.

RESULTS

Although we identified 26 eligible studies, only 3 were randomized controlled trials (RCTs), comparing regimens that differed in the repeat-dose misoprostol component. These trials did not detect differences in effectiveness between the randomized groups. One RCT found evidence of higher effectiveness from repeat misoprostol doses among a subgroup of women with more advanced gestations.

CONCLUSIONS

Although clinicians often prescribe a repeat dose of misoprostol to increase effectiveness in medication abortion, the effect of the repeat dose has not been established. Because mifepristone followed by a single misoprostol dose is highly effective in inducing abortion, determining the effect of a repeat misoprostol dose would require a large sample size. The resource expenditure on such large trials might not be warranted. Any future studies should use induction-to-completion time to measure effectiveness and should assess acceptability and side effects.