By the age of 30, a woman will have lost approximately 90% of the eggs she was born with. This significant decline in egg reserve is a key factor contributing to decreased fertility in women over 30.
Understanding Ovarian Reserve
A woman is born with all the eggs she will ever have. This number is estimated to be around 6–7 million at 20 weeks gestation. However, this number significantly decreases throughout a woman's life. The depletion of eggs, a process called oocyte atresia, is a natural part of aging. By the time a woman reaches puberty, this number has dropped considerably.
Egg Loss Timeline:
- Birth: ~6-7 million eggs
- Age 30: ~90% of eggs are lost, leaving a significantly smaller reserve.
- Age 40: Only around 3% of original eggs remain.
While the loss of 90% of eggs by age 30 is a significant milestone, it's crucial to understand that fertility isn't solely determined by the number of remaining eggs. Egg quality also plays a vital role. Egg quality typically declines with age, increasing the risk of chromosomal abnormalities and impacting the chances of successful conception.
The Impact of Age on Fertility:
While it's true that egg quantity significantly diminishes by age 30, it doesn't mean pregnancy is impossible after this age. Many women conceive naturally in their 30s, and even 40s, although the chances decrease with age. The remaining eggs are still viable, but the probability of a healthy pregnancy is lower due to age-related factors impacting both egg quality and overall reproductive health.
Important Note: The statement "90% of a woman's eggs are gone by age 30" is a generalization based on average statistics. The actual number can vary between individuals.
