Methotrexate. A single agent for early abortion

To determine whether methotrexate as a single agent for induced abortion in pregnancies up to 5 weeks is as effective, has fewer side effects and is as acceptable to subjects as the combination of methotrexate and misoprostol.

Women with no greater than a 5-week gestation were compared with a historical control group of consecutive women presenting for a medical abortion matched for gestational age. Subjects received intramuscular methotrexate on day 1. The study group received no misoprostol until day 21, when it was offered if the abortion had not yet occurred. The control group self-administered one or more doses of misoprostol within the first week after methotrexate. A complete abortion was defined by either negative transvaginal ultrasound or negative urine pregnancy test. All subjects completed a daily symptom log and satisfaction questionnaire. The analysis consisted of a comparison of the study group and control group for completion and timing of the abortion, symptoms and subject satisfaction.

There were 40 study subjects and 53 controls. All subjects had a medical abortion without surgery. Ten (25%) of the 40 study subjects reached study day 21 without bleeding: 4 used misoprostol and 6 chose to wait for the abortion to occur spontaneously. One of the 10 subjects had persistent embryonic cardiac activity at 21 days and aborted after misoprostol. The mean number of days to bleeding was 15.5 days (SD 7.8 days) for the study group as compared with 8.1 days (SD 11.3) (P = .0003) for the control group. There was no significant difference in the number of days of bleeding, gastrointestinal side effects or reported subject satisfaction.

While methotrexate as a single agent was effective in inducing abortion in early pregnancy, 15% of the study subjects finally used misoprostol, the abortion took significantly longer, and side effects were not less common as compared with those in subjects who received the combination of methotrexate and misoprostol.