Ovarian reserve depletion

The number of primordial follicles that will give rise to mature eggs decreases dramatically from embryonic development until it reaches puberty.

At the time of puberty there will be about 300,000 eggs that will be released in the menstrual cycles during the reproductive life. This number of follicles constitutes the ovarian reserve of the woman and decreases as age increases.

Normally, women are born with a sufficient number of eggs to be released until they are at least 50 years old.