Congenital heart defects happen when the heart doesn't form normally as the developing baby (fetus) grows in the uterus. Heart defects may cause problems with blood flow through the heart after a baby is born. The problems can affect the baby's blood and oxygen supply.
There are many types of congenital heart defects. If the defect lowers the amount of oxygen in the body, it is called cyanotic. If the defect doesn't affect oxygen in the body, it is called acyanotic. Some defects require treatment right away. Other defects get better on their own and don't require treatment.
Only about one-third of full-term babies born with a congenital heart defect have major defects that need surgery or have defects that may cause death during the first year of life.1
Not all defects are found when a child is very young. Some defects don't cause symptoms and aren't life-threatening. These defects may not be found until the teen years or later.
Many children and adults with corrected heart defects lead healthy lives. But the treatments they've had or the defect itself can cause or be related to long-term problems. These include:
If you are an adult with a congenital heart defect, see the topic Congenital Heart Defects in Adults.
You may have to make decisions about things like: