Weight Regain following Bariatric Surgery and in vitro Fertilization Outcomes.

Introduction: The aim of this study was to estimate the time to pregnancy and live birth and evaluate the effect of weight regain in women with a history of bariatric surgery (BS) who underwent in vitro fertilization (IVF) treatments.

Methods: This is a retrospective cohort study. All patients with previous BS who underwent IVF treatment in a tertiary university-affiliated hospital between 2013 and 2022 were included. Time to pregnancy and live birth were compared between patients who regained less than or greater than three points of body mass index (BMI) from the nadir weight after BS. Kaplan-Meier curves and log-rank tests were used to compare groups.

Results: A total of 78 patients were included in this study. The positive β-hCG, clinical pregnancy, and live birth rates following BS were 89.4%, 78.9%, and 50.8%, respectively. The median time from the beginning of IVF treatments to a positive β-hCG test was 2.97 months (95% CI: 1.04-4.89 months), to a clinical pregnancy was 7.1 months (95% CI: 3.56-10.91), and to a live birth was 20.2 months. Women who maintained their nadir BMI following BS had nearly twice the chance of achieving a clinical pregnancy (HR 1.967, 95% CI: 1.026-3.771, p = 0.042) and were approximately three times more likely to achieve a live birth (2.864, 95% CI: 1.196-6.859, p = 0.018) than those who regained at least three points of BMI.

Conclusion: Weight regain after BS is associated with a lower rate of live births and prolonged time to achieve clinical pregnancy and live birth.