Human eggs: How many and for how long?

Dear Reader,

Unlike sperm, which are produced daily throughout a lifetime, human eggs are finite and found in one — okay, two baskets (ovaries). To be more precise, when a person with ovaries is born, they contain about one to two million immature eggs, or follicles.

Over a lifetime, the vast majority of follicles will die through a process known as atresia. Atresia begins at birth and continues throughout the course of the reproductive life. When puberty is reached and menstruation begins, only about 400,000 follicles remain. With each menstrual cycle, a thousand follicles are lost and only one lucky little follicle will actually mature into an ovum (egg), which is released into the fallopian tube, kicking off ovulation. That means that of the one to two million follicles, only about 400 will ever mature.

Relatively little or no follicles remain at menopause, which usually begins between 48 to 55 years of age. The remaining follicles are unlikely to mature and become viable eggs because of the hormonal changes that come along with menopause.

Thanks for your egg-cellent question!