Body mass index and short-term weight change in relation to treatment outcomes in women undergoing assisted reproduction.

OBJECTIVE

To assess the relation between body mass index (BMI) and short-term weight change with assisted reproductive technology (ART) outcomes.

DESIGN

Prospective cohort study.

SETTING

Fertility center.

PATIENT(S): A total of 170 women undergoing 233 ART cycles.

INTERVENTION(S): Baseline BMI and short-term weight change were related to ART outcomes. Regression models accounting for repeated observations were used to adjust data for potential confounders.

MAIN OUTCOME MEASURE(S): Peak E2 levels, oocyte yield, MII yield, fertilization rate, embryo quality, postive [beta]-hCH, clinical pregnancy and live birth rates.

RESULT(S): Overweight and obesity were associated with lower live birth rates. The adjusted live birth rate (95% confidence interval) was 42% (28%-58%) among women with a BMI between 20 and 22.4 kg/m(2) and 23% (14%-36%) among overweight or obese women. Short-term weight loss was associated with a higher proportion of metaphase II (MII) oocytes retrieved. The adjusted proportion of MII eggs was 91% (87%-94%) for women who lost 3 kg or more and 86% (81%-89%) for women whose weight remained stable. This association was stronger among women who were overweight or obese at baseline. Short-term weight loss was unrelated to positive β-hCG, clinical pregnancy, or live birth rates.

CONCLUSION(S): Overweight and obesity were related to lower live birth rates in women undergoing ART. Short-term weight loss was related to higher MII yield, particularly among overweight and obese women, but unrelated to clinical outcomes.