Congenital heart defects are structural heart problems or abnormalities that have been present since birth.
Congenital heart defects usually have no known cause. In some cases, they may be passed from a parent to a child (inherited). They also may occur in the developing baby (fetus) of a woman who has an infection or who is exposed to radiation or other toxic substances during her pregnancy.
Most congenital heart defects are detected shortly after birth, although some are not discovered for years. Some defects are severe enough to cause death. Some resolve on their own and may not need any treatment. Babies with large or complex defects usually require surgery. Many children with corrected heart defects go on to lead normal lives. But they usually require lifelong monitoring of their condition.
WebMD Medical Reference from Healthwise