Over the past 4 decades, because of cultural and social changes, women in the developed world have significantly delayed childbirth. It is well known that fertility decreases with age and that live birth rates in women over the age of 35 are significantly lower both naturally and with assisted reproduction compared to those in women under the age of 35. The decline in live birth rate reflects an increase in oocyte aneuploidy that leads to reduced embryo quality as well as an increased incidence of miscarriages and birth defects, most prominently Down's syndrome (trisomy 21). There is evidence that older infertility patients have abnormal oocyte mitochondrial activity and reduced production of ATP. The meiotic spindle, crucial for normal chromosome segregation, may not be formed properly in the absence of appropriate ATP levels. Altered spindles may result in aneuploid embryos, which implant poorly or not at all.