Goldman RH, et al. - Researchers examined how age and body mass index (BMI) in combination impact the cumulative live birth rate following in vitro fertilization (IVF), in order to inform when delaying IVF treatment to achieve a lower BMI may be beneficial or detrimental to the likelihood of live birth. Using linked fresh and cryopreserved/frozen cycles from the Society for Reproductive Technology Clinic Outcome Reporting System, representing >90% of IVF cycles performed in the United States, they identified 51,959 first fresh cycles using autologous eggs and 16,067 subsequent frozen embryo transfer cycles. Compared to BMI, age-related decline in fertility has a higher impact on the cumulative live birth rate at older ages. This suggests a detrimental impact of taking time to achieve lower BMI prior to IVF for older women with overweight or obesity. Hence they recommend considering the combination of age and BMI in delaying conception to lose weight prior to IVF.