Impact of body mass index on in vitro fertilization outcomes

Purpose: To determine if body mass index (BMI) impacts IVF outcome. Methods: Retrospective, cohort study. Main outcome measure was number of oocytes obtained. Results: BMI did not correlate with the prestimulation parameters. There was a significant positive correlation between BMI and the number of follicles on ultrasound prior to egg retrieval. A threshold analysis revealed a significant change in parameters at a BMI > 24 kg/m(2). Patients with BMI > 24 kg/m(2) demonstrated a significant increase in the number of follicles after stimulation ( p = 0.03) and a comparative decrease in the number ampules of gonadotropins used ( p = 0.04) and days of stimulation required ( p = 0.01). Conclusion: These data demonstrated that an elevated BMI significantly correlates with the number of follicles, days of stimulation, and number of ampules of gonadotropins used. Further correlation to an actual increase in number of oocytes and pregnancy rates may be limited by insufficient power in this study.