More Study Needed of Preferred Regimens for Medication Abortion Beyond 70 Days

摘要

To the Editor: The mifepristone (Mifeprex) package insert states that it is "...indicated, in a regimen with misopros-tol, for the medical termination of intrauterine pregnancy through 70 days gestation."1 The article by MacNaughton and colleagues states, "Evidence-based regimens, however, demonstrate safety and effectiveness of medication abortion up to 77 days' gestation." However, in the article cited for that sentence, it states that "Although the success rate at 71-77 days of gestation was within the non-inferiority margin, we cannot rule out that it is statistically worse than in the previous gestational week. Significantly more ongoing pregnancies in the later group raise concerns about using the regimen at 71-77 days."2 An additional citation states, "Regimen effectiveness was high at 64-70 and 71-77 days among clients who attended follow up. However, with 25 attrition, it is difficult to draw definitive conclusions about effectiveness and associated safety," and "Mifepristone 200 mg followed by two doses of misoprostol 800 meg four hours apart is a promising medical abortion regimen to improve efficacy in pregnancies from 64-77 days of gestation as compared to regimens with an initial single misoprostol dose. Prospective research is recommended to achieve more robust efficacy estimates."3