“…By accounting for the confounding effects of obesity on oocyte development and ovulation using oocyte donation, this model suggests that poor endometrial receptivity contributes to the increased miscarriage rate observed in obese women. In a large retrospective study, spontaneous abortion rates were higher in obese women undergoing hormonally substituted frozen embryo transfer cycles but not in fresh IVF/ICSI cycles or frozen cycles after spontaneous ovulation (35). That study suggests that follicle development contributes to (or at least is reflective of) an environment conducive to early embryo development.…”