Effect of increased body mass index on oocyte and embryo quality in IVF patients

Obesity may have an adverse effect on the outcome of IVF/intracytoplasmic sperm injection (ICSI) treatment. In this study, the effects of increased body mass index (BMI) on oocyte and embryo quality during IVF cycles were studied. A retrospective analysis of 426 IVF/ICSI cycles was performed. Cycles were classified according to the BMI: normal BMI (19-24.9 kg/m2), overweight (25-29.9 kg/m2) and obese (>30 kg/m2). Cycles were further stratified based on age (group 1, <35 years; group 2, ≥35 years). Markers of oocyte quality (number of oocytes inseminated and fertilization rate) and embryo quality (utilization rate, number of embryos discarded and cryopreserved, and mean embryo grade) were examined. In group 1, obesity had a significant adverse effect on the mean embryo grade (P = 0.02), the embryo utilization rate (P = 0.01), number of embryos discarded (P = 0.007) and cryopreserved (P < 0.05). In group 2, there was no difference in markers of embryo quality between the three BMI ranks. Obesity did not have any significant effect on markers of oocyte quality or clinical pregnancy rates. In conclusion, obesity may adversely affect embryo quality in young women (<35 years) undergoing IVF/ICSI, while the oocyte quality is not affected.