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Birth defects research


  • The processes of development still hold many mysteries.
  • We're working to prevent birth defects and find treatments.
  • Sought: genetic and environmental causes of birth defects.

Most common questions

What are the most common birth defects?

Congenital heart defects are among the most common birth defects, affecting nearly 1 out of 100 babies in the United States. Some heart defects are mild, while others can be life-threatening. Other common birth defects include cleft lip/palate, Down syndrome and spina bifida (open spine), affecting about 1 in 700, 1 in 800 and 1 in 2,500 babies respectively.

Can birth defects be prevented?

Most birth defects cannot be prevented because their causes are not known. However, women can take a number of steps before and during pregnancy to reduce their risk [link to Birth Defects fact sheet]. These steps include taking a multivitamin containing 400 micrograms of folic acid daily starting before pregnancy and in early pregnancy. This helps to prevent serious birth defects of the brain and spinal cord, including spina bifida, and may also help prevent heart defects.

What environmental factors may cause birth defects?

Environmental substances that can contribute to birth defects include alcohol, certain drugs/medications and infections. Women who drink heavily during pregnancy are at risk of having a baby with a pattern of mental and physical birth defects called fetal alcohol syndrome. Because even moderate or light drinking may harm a baby, women who are pregnant or planning pregnancy should not drink any alcohol. They also should avoid illegal drugs such as cocaine and Ecstasy, and ask their health care provider about the safety of any prescription and over-the-counter medications they take. Women also can take steps to help prevent certain infections such as toxoplasmosis and cytomegalovirus that can cause birth defects.