Congenital heart defects are problems with how a baby's heart forms. "Congenital" means that the heart problem develops before the baby is born or at birth.
Most congenital heart defects affect how blood flows through the heart or through the blood vessels near the heart. Some defects may cause blood to flow in a pattern that isn't normal. Others can completely or partially block blood flow.
There are many different types of congenital heart defects. They can be fairly simple, such as a hole between the chambers of the heart or a heart valve that has not formed right. Others are more serious and complex, such as a missing heart valve or heart chamber.
Some defects are discovered in the fetus (developing baby) while a woman is pregnant. Others are not found until birth. Still others may not be discovered until your child gets older or even until he or she is an adult.
No matter when a heart defect is discovered, having a child with a heart problem is very stressful. Dealing with the fear and uncertainty may seem overwhelming, especially when you have a fragile newborn. It may help you to learn as much as you can about your child's treatment and to talk to your doctor and other parents who have a child with similar problems.
No one knows exactly what causes most congenital heart defects. Genes passed down from a parent are a possible cause. Viral infections also may play a role. For example, if a woman gets German measles (rubella) while she is pregnant, it may cause problems with how her baby's heart develops. Women who have diabetes have a greater chance of having a child with a congenital heart defect.
Congenital heart defects are more common in babies who are born with genetic conditions such as Down syndrome.
Taking some prescription or other medicines during pregnancy may cause congenital heart defects. Women who use illegal "street" drugs or who drink alcohol during pregnancy have a higher risk of having a baby with a congenital heart defect.