Some people say only women above thirty-five years. Others say any woman.

Experts, over to you.

4everisaac: Some people say only women above thirty-five years. Others say any woman.

Experts, over to you.

Briefly, women who are above forty years have a high risk of having a Down's baby....but those who are under 40 also have some risk too.

As this Medscape article puts it....

Advanced maternal age remains the only well-documented risk factor for maternal meiotic nondisjunction. However, understanding of the basic mechanism behind the maternal age effect is lacking. Maternal age risk factors are as follows:

With a maternal age of 35 years, the risk is 1 in 385
With a maternal age of 40 years, the risk is 1 in 106
With a maternal age of 45 years, the risk is 1 in 30