Efficacy of early induced medical abortion with mifepristone when beginning progestin-only contraception on the same day

Abstract Objectives To investigate whether starting progestin-only contraception immediately after mifepristone reduced the efficacy of early medical abortion with a mifepristone–misoprostol regimen. Methods A review of patient records from October 1, 2012 to March 31, 2013 from four Marie Stopes Mexico clinics in Mexico City was conducted. Patients were eligible for inclusion if they had undergone a medical abortion with mifepristone–misoprostol at no later than 63 days of pregnancy, had a recorded outcome, and had either started progestin-only contraception immediately after mifepristone administration or had not started contraception. The primary outcome–successful induced abortion–was defined as the complete evacuation of uterine contents without the need for further intervention. A secondary outcome was the number of induced abortions completed without the need for manual vacuum aspiration. Results Records from 2204 patients were included; 448 (20.3%) patients had started progestin-only contraception, and 1756 (79.7%) had not. Patients not taking progestin-only contraception were significantly more likely to be primigravidas and nulliparous. Medical abortion success did not vary between the two groups; 1890 (85.8%) were successful and 2085 (94.6%) were completed without the need for manual vacuum aspiration. Different methods of progestin-only contraception did not affect medical abortion outcomes. Conclusion Beginning progestin-only contraception immediately following mifepristone for early medical abortion was not associated with reduced medical abortion effectiveness.