Presentation (CTI)

OBJECTIVES: Recent analysis by ethic and public policy center has asserted that the real-world incidence of adverse events (AEs) following mifepristone (Mifeprex) abortion is up to 22 times higher than rates reported in US Food and Drug Administration (FDA) clinical trials, leading to the consideration of reinstating earlier safety restrictions. In contrast, European regulations for prescription o mifepristone are generally less stringent than those in the United States.
METHODS: We analyzed patients data from Kythera Labs Commercial and Medicaid claims data 2017-2024. Mifepristone abortions were identified using a combination of procedure codes, prescriptions, and diagnosis codes for elective termination or unwanted pregnancy, consistent with manufacturer reimbursement guidelines for each state and insurer. Patients were matched based on age, comorbidities, and socioeconomic status using propensity score matching (PSM). Serious AEs, including sepsis, infection, transfusion, hemorrhage, hospitalization, and emergency room visits, occurring within 45 days of abortion were evaluated.
RESULTS: The study included 301,972 commercial and 78,140 Medicaid patients. Unadjusted rates of serious AEs were significantly lower than those reported by the policy center, with 7% in commercial claims and 5% in Medicaid claims. Patients experiencing AEs were older, resided in lower socioeconomic areas, and had higher comorbidity burden (p<0.001). After PSM, AE rates were reduced by nearly by one-quarter.
CONCLUSIONS: Real-world rates of serious AEs following mifepristone abortion were higher than those reported in clinical trials, but approximately 75% lower than recent public policy estimates. Additional restrictions on mifepristone, especially post-Dobbs v Jackson Women's Health Organization, may further limit abortion access and disproportionately impact women in US states with abortion bans who must travel for care.