What Increases Your Risk

In most cases, the cause of a congenital heart defect isn't known. But certain things increase your baby's chances of having a heart defect. These include:

• Family history. A child's risk for having a congenital heart defect increases if a brother, sister, or parent has one.
• Other genetic conditions. For example, Down syndrome has been linked to these defects.
• Premature birth. Babies born too early have a higher chance of having a heart defect.
• Chronic conditions. Babies born to women with diabetes or phenylketonuria have a higher chance of having a heart defect.
• Use of alcohol or drugs. Women who drink alcohol, take certain prescription or over-the-counter medicines, or use illegal street drugs during pregnancy may cause the baby to have a heart defect.

If you're concerned about having a baby with a congenital heart defect, you can take steps to lower your risk. For healthy pregnancy choices, see the topic Pregnancy.