What is a congenital heart defect?

A baby may really look blue at birth, and may just need some oxygen for a few minutes to turn him a healthy pink. But if he stays blue, he may have a congenital heart defect (CHD) and may need immediate medical attention.

There are other, non-cardiac causes of blueness at birth, such as lung or blood abnormalities, but this discussion deals only with heart abnormalities.

What is a congenital heart defect?
The simplest definition is "a structural abnormality that is present at birth". As the heart takes many weeks to form, it follows that the abnormality must have arisen before birth.

The abnormality can occur in any part of the heart:

• The receiving (atria) or pumping (ventricles) chambers
• The wall (septum) dividing the right (oxygen-poor) and left (oxygen-rich) sides of the heart
• The inlet valves (tricuspid and mitral ) separating the receiving and pumping chambers
• The outlet valves from the pumping chambers (aortic and pulmonary)
• Abnormal positioning of the major vessels entering or leaving the heart
• Obstructions to flow
• Detours of blood flow

There may also be a combination of several of these malformations.

(The Heart and Stroke Foundation SA/Health24, updated January 2009)