A woman is born with approximately 1 to 2 million eggs (oocytes) in her ovaries. This number represents the peak of her lifetime egg supply, which starts to decline even before birth from about 6 to 7 million eggs in the fetal stage down to 1 to 2 million at birth
. By the time she reaches puberty, the egg count decreases to around 300,000 to 400,000 eggs due to natural loss processes occurring during development
. Throughout her reproductive years, a woman will ovulate roughly 300 to 400 eggs, with many more eggs lost through a process called atresia, where immature eggs degenerate and are reabsorbed by the body
. In summary:
- Fetal stage (around 20 weeks gestation): ~6 to 7 million eggs
- At birth: ~1 to 2 million eggs
- At puberty: ~300,000 to 400,000 eggs
This fixed number of eggs steadily declines with age until menopause, when the egg supply is exhausted
