Congenital (kon-JEN-i-tal) heart defects are problems with the heart’s structure that are present at birth. These defects can involve the interior walls of the heart, valves inside the heart, or the arteries and veins that carry blood to the heart or out to the body. Congenital heart defects change the normal flow of blood through the heart.

There are many different types of congenital heart defects. They range from simple defects with no symptoms to complex defects with severe, life-threatening symptoms. Congenital heart defects are the most common type of birth defect, affecting 8 of every 1,000 newborns. Most of these defects are simple conditions that are easily fixed or need no treatment.

A small number of babies are born with complex congenital heart defects that need special medical attention soon after birth. Over the past few decades, the diagnosis and treatment of these complex defects has greatly improved.