What is the likelihood of a 40-year-old giving birth to a child with Down Syndrome based on statistics?

The likelihood of a 40-year-old woman giving birth to a child with Down Syndrome is approximately 1 in 100. This statistic reflects the increased risk associated with maternal age, particularly after age 35. As women age, the probability of chromosomal abnormalities, such as trisomy 21, which causes Down Syndrome, increases due to factors related to oocyte aging.

At age 40, statistical models and population studies indicate that the risk for Down Syndrome rises to about 1 in 100, signifying a noteworthy increase compared to younger mothers. This statistic is important for genetic counseling, as it helps professionals provide informed guidance regarding prenatal testing options and associated risks for expectant parents.