Females are born with a finite number of eggs (oocytes) in their ovaries. The typical numbers are:
- At about 20 weeks of gestation (fetal stage), a female fetus has approximately 6 to 7 million eggs.
- By birth, this number decreases to around 1 to 2 million eggs.
- By the time puberty begins, only about 300,000 to 500,000 eggs remain.
- Throughout a woman's reproductive life, only about 400 eggs are ovulated; the rest gradually degenerate and are lost over time until menopause
While some recent studies suggest the possibility that adult mammals might produce new eggs from stem cells, the prevailing scientific consensus remains that females are born with their lifetime supply of eggs, which declines over time
