Efficacy of Misoprostol Alone for First-Trimester Medical Abortion: A Systematic Review

Abstract

Objective:

To summarize available data on the effectiveness and safety of single-agent misoprostol for medical abortion in the first trimester.

Data Sources:

We searched Medline, CABI, Cochrane, EMBASE, LILACS, and the Web of Science, and ClinicalTrials.gov for English language studies that evaluated misoprostol alone for abortion of viable pregnancy in the first trimester.

Methods of Study Selection:

Our search yielded 1562 citations, of which 38 included data from 53 trial groups that met our inclusion and exclusion criteria.

Tabulation, Integration, and Results:

We abstracted data about each trial group, including study characteristics, treatment regimen, clinical protocol, number of women treated and followed, and numbers with outcomes of interest. We used meta-analytic methods and logistic regression to examine factors associated with surgical intervention after treatment. Among all 12,829 evaluable women, 2536 (meta-analytic estimate 22.0%, 95% CI 18.8%, 25.5%) had surgical uterine evacuation. Multiple factors were significantly associated with this proportion, including misoprostol amount per dose and route of administration, loss to follow-up rate, publication date, geographic region, number of misoprostol doses, duration of dosing, and time between dosing and evaluation. Of 6359 evaluable women, 384 (meta-analytic estimate 6.8%, 95% CI 5.3%, 8.5%) had ongoing pregnancy. At most 26 of 12,184 evaluable women (meta-analytic estimate 0.7%, 95% CI 0.4%, 1.0%)were transfused or hospitalized for abortion-related reasons. In trials that provided satisfaction data, most of women were satisfied or very satisfied with the treatment (meta-analytic estimate 78%, 95% CI 71%, 85%).

Conclusions:

Misoprostol alone is effective and safe and is a reasonable option for women seeking abortion in the first trimester. Research is indicated to further refine the regimen and to establish efficacy in the late first trimester.

Systematic Review Registration:

PROSPERO, CRD42018083589.

PRECIS

Treatment regimens that contain only misoprostol can be effective and safe for first-trimester medical abortion.