Outcomes of early first-trimester medical abortion following bariatric surgery: A retrospective cohort study.

OBJECTIVE: To compare medical termination of pregnancy (TOP) failure in patients with and without prior bariatric surgery (BS) and to compare outcomes by BS subtype. METHODS: We performed a retrospective cohort study of medical TOP at a single university teaching center between January 2019 and April 2024. A total of 81 patients with prior BS were matched 1:4 to 324 controls by gestational-age group and admission date. All patients received 200 mg oral mifepristone followed 48 h later by 800 μg buccal misoprostol. Failure was defined as any additional intervention beyond this regimen. Multivariable logistic regression adjusted for prespecified confounders. RESULTS: Overall failure occurred in 15/81 (18.5%) patients with prior BS and 37/324 (11.4%) controls (P = 0.09). After adjustment, prior BS was not significantly associated with failure (adjusted odds ratio [aOR] 1.95; 95% confidence interval [CI]: 0.99-3.84). Within the BS cohort, failure rates were 6/43 (14.0%) after malabsorptive bariatric surgery (MBS) and 9/38 (23.7%) after restrictive bariatric surgery (RBS) (P = 0.26); however, after adjustment for time since surgery, RBS was associated with higher odds of failure (aOR 5.48; 95% CI: 1.2-25.1). CONCLUSION: Prior BS was not significantly associated with medical TOP failure overall, although a trend toward increased risk was observed. In subgroup analysis, RBS was associated with higher adjusted odds of failure than MBS. These results highlight the need for further prospective research to evaluate whether procedure-specific protocols or enhanced monitoring are warranted in this unique population.