Congenital heart disease is a collective term for heart defects present at birth. One in every 100 babies has a heart defect at birth. Affected babies may have a blockage in the heart or blood vessels, abnormal blood flow to their heart, or an underdeveloped heart. The cause of congenital heart defects is unknown in about 80% of the cases.

The five common heart defects are:

• Septal defects. Babies with a septal defect have a hole between two of their heart’s chambers.
• Coarctation of the aorta. It is the narrowing of the largest artery in the body–the aorta.
• Pulmonary valve stenosis. It is the narrowing of the pulmonary valve (this valve controls the passage of blood from the heart to the lungs).
• Transposition of the great arteries: It occurs when the two main arteries leaving the heart are reversed in position or transposed.
• Underdeveloped heart: Certain parts of the heart are not fully developed.

Congenital heart disease may be diagnosed during pregnancy or after birth.

Suppose your doctor suspects a heart defect during a routine ultrasound scan of the unborn baby. In that case, they will order fetal echocardiography at around 18 to 22 weeks of pregnancy. Echocardiography (a type of ultrasound) uses sound waves to create a picture of your baby’s heart.

A doctor may diagnose a heart defect shortly after birth by observing signs such as a blue tinge to your baby’s skin or lips. During a newborn physical examination, a doctor will check your baby’s heart, feel their pulse, and listen to heart sounds. They may also recommend other diagnostic tests, such as ECG, chest X-ray, and pulse oximetry.

Most cases are mild and don’t need treatment, though regular check-ups may be necessary. Several cases are treated with surgery, medications, and long-term monitoring.