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A repeat dose of misoprostol 800mcg following mifepristone for outpatient medical abortion at 64-70 and 71-77 days of gestation: A retrospective chart review

Expanding outpatient medical abortion with mifepristone and misoprostol through 11 weeks (77 days) of pregnancy

Medical abortion with mifepristone and misoprostol is increasingly used as an outpatient alternative to aspiration, but scant evidence has limited its offer beyond 10 weeks of pregnancy in many clinics and facilities as a first trimester option. We sought to bridge the evidence gap about outpatient medical abortion in the later first trimester. Better information about how well a common medical abortion regimen works in the 11th week of pregnancy is beneficial for health providers and for people who prefer to avoid aspiration procedures. An effective medical abortion regimen through 11 weeks also increases access to safe abortion care where providers trained in aspiration are scarce.

We conducted two sequential studies to evaluate the success of medical abortion regimens in the 11th week of pregnancy.

(1) The first study used a common first trimester outpatient regimen of mifepristone 200mg followed 24-48 hours later by misoprostol 800mcg. Our findings demonstrated a very good chance of success with this regimen, regardless of whether a person was in the 10th week or 11th week of pregnancy. Successful abortion occurred in 92.3% of the 10th week pregnancies (consistent with previously published studies) and in 86.7% of the 11th week pregnancies. The lower success rate in the 11th week was because nearly 9% of pregnancies continued after using the medication regimen. This regimen could be a reasonable option for medical abortion users with 11 week pregnancies, given high success (and safety and acceptability), but the significant increase in continuing pregnancies is concerning.

(2) The second study examined retrospectively relevant data from medical charts of people in the 10th and 11th weeks of pregnancy who had outpatient medical abortions with two doses of misoprostol 800mcg instead of one after the usual mifepristone. 99.6% of people in the 10th week and 97.7% of people in the 11th week who returned for follow up had successful medical abortions. One client (0.4%) in the 10th week and 3 clients (1.4%) in the 11th week had continuing pregnancies. These represent much higher success and lower ongoing pregnancy rates than those observed in the first study with one misoprostol dose. Nevertheless, a high proportion (25%) of clients among the charts that we reviewed did not return to the clinic for follow up, which makes it difficult to draw definitive conclusions about the success of the two-misoprostol-dose regimen since it is possible that those who did not return had continuing pregnancies (or other complications).

The bottom line: Mifepristone 200mg followed by 800mcg repeated once after 4 hours is a very promising regimen to improve success over regimens that use mifepristone and a single misoprostol dose in the 10th and 11th weeks.