//Ovarian Aging

With age, there is a decline in both the quantity and quality of the pool of follicles and oocytes. Linear extrapolation of follicular depletion in women with regular menses predicts that, by 50 years of age, each ovary would contain 2500 to 4000 primordial follicles. Because the menopausal ovary is largely devoid of follicles, follicular depletion apparently accelerates in the last decade of reproductive life (Fig. 8-20). Below a critical number of some thousand follicles, which is reached at a mean age of 45 to 46 years, menstrual irregularity occurs. In some studies, unilateral oophorectomy and nulliparity are associated with an earlier occurrence of menopause and increasing parity with later menopause.