Aging of the reproductive system is a complex and multifactorial process, dependent on changes in the hypothalamus, pituitary, ovary and uterus.
From the early fetal period number of the oocytes gradually declines and the proportion of ovarian cells undergoing apoptosis increases. The risk of genetic aberrations inclines in the offspring of advanced age mothers, that is mainly due to nondisjunction of homologic chromosomes. Serum FSH levels increase due to lower ovarian inhibin secretion and with advanced aging alterations affect also LH and estradiol levels. Number of anovulatory cycles increases and the luteal phase is shortened that also limit fertility.
Mechanisms regulating the decline of fertility potential with aging remain unknown and still many questions have no answers. It is believed that the key role is attributed to the ovary and all the other processes are secondary.