What is Congenital Heart Disease?

One out of every 100 infants born in the United States has a congenital (present at birth) heart defect. Heart defects occur as the baby’s heart is developing during pregnancy before the baby is born. Congenital heart defects are the most common birth defect.

A baby's heart begins to develop at conception. It is completely formed eight weeks into the pregnancy. Congenital heart defects happen during these first eight weeks of the baby’s development.

Congenital heart defects are a result of crucial development steps not occurring at the right time, or in the correct order. This means the child may be born with a single blood vessel where two vessels should be. Or there may be a hole between two heart chambers that should be separated. Often-times, an echocardiogram (ultrasound of the heart) is the best way to determine if a heart defect exists, what type it is, and to what extent blood flow has been changed. This information helps the care team decide the best treatment plan.

Causes of Congenital Heart Defects

Most congenital heart defects have no known cause. Mothers (and fathers) often wonder if something they did during the pregnancy caused the heart problem. This is rarely the case.

Some congenital heart defects do occur more often in families. This shows that there may be a genetic link.

This is usually not the cause of most types of congenital heart defects. Some congenital heart defects occur if the mother had a certain disease while pregnant (like rubella) or was taking certain medicines (like anti-seizure medicines).

In most cases, there is no specific reason as to why the heart defect occurred.

Types of Congenital Heart Defects

Congenital heart defects can range from simple to complex. Some can be watched by the child's doctor and managed with or without medicines. Others will need surgery. Some surgeries happen in the first few hours of life.

A child may even "grow out" of some of the simpler heart defects. This can happen with a patent ductus arteriosus (PDA) or atrial septal defect (ASD), as these defects may resolve on their own as the child grows.

Other infants will have a combination of defects. They may need several surgeries throughout their life.

Congenital heart defects can be classified into several categories. This helps understand the problems the baby will experience.

Too Much Blood Passes through Lungs

These defects allow oxygen-rich (red) blood that should be traveling to the body to recirculate through the lungs. This causes increased pressure and stress in the lungs. Examples are:

Too Little Blood Passes through Lungs

These defects allow blood that has not been to the lungs to pick up oxygen to travel to the body. This is called oxygen-poor blood. The body does not get enough oxygen with these heart problems. The baby will be cyanotic, or "blue." Examples are:

Too Little Blood Travels to Body

These defects are a result of underdeveloped chambers of the heart or blockages in blood vessels. This stops the right amount of blood from getting to the body to meet its needs. Examples are:

Combination of Defects

Sometimes, there will be a combination of several heart defects. This makes a more complex problem that can fall into several categories.

Who Treats These Conditions?

Babies with congenital heart problems are treated by specialists called pediatric cardiologists. These doctors diagnose heart defects. They manage the health of children before and after surgical repair of the heart problem.

Specialists who surgically correct heart problems in the operating room are known as pediatric cardiovascular or cardiothoracic surgeons.


Last Updated 12/2023

Reviewed By Carvey Wright, MSN, RN, CPN, Education Specialist II