What are the main reasons for the decline in fertility after 40?
A key reason why women have barriers to fertility after 40 is that as women age, so do the eggs in her ovaries. These aged eggs are more likely to have genetic abnormalities. Eggs are created by cell division and as the woman gets older, there is a greater chance for mistakes to occur in the division process. Those mistakes can cause an abnormal number of chromosomes in the egg. Due to the higher number of eggs with abnormal chromosomes that a 40-year-old possesses, the complications of these genetic abnormalities are threefold for the woman trying to increase fertility after 40. First, a child born with a chromosomal abnormality can suffer from birth defects and severe medical conditions. The most well-known of these is Down syndrome. A child born to a 40-year-old mother has a 1/66 chance of having a chromosomal abnormality. The chances increase with each year after that. In comparison, a 30-year-old mother has a 1/385 chance of having a child with genetic abnormalities. Next, if one
