There is no way to prevent Down syndrome. However, the chance of having a child with Down syndrome increases as the age of the mother increases. Older mothers usually are offered additional screening tests to find Down syndrome in the womb (uterus). Some researchers have suggested that an older father also increases the risk.
Parents who already have a child with Down syndrome are more likely to have another child with the same problem in future pregnancies. Genetic testing can help to determine the amount of risk.