What Are the Tests for Congenital Heart Defects?

Reviewed by James Beckerman, MD, FACC on September 10, 2020

You’ll naturally want to know as soon as possible if your baby was born with a heart problem -- a congenital heart  Doctors have several tests they can do to diagnose congenital defects.


Tests Before Birth

Even before your baby is born, your doctor might be able to identify a congenital heart defect with certain tests.

Fetal echocardiogram. A test called a fetal echocardiogram uses pictures made by an ultrasound to show the heart in motion, and allows your doctor to see things that are wrong with its valves and structure.

Genetic counseling. A geneticist takes a small blood sample before or during your pregnancy. It’s important because if you or a family member has an abnormality, your child’s chances of having it can go up by as much as 50%.

Tests After Birth

Echocardiogram. This painless ultrasound of the inside of your baby’s heart can detect almost any kind of congenital heart defect. It usually takes less than an hour for a doctor to perform.


Electrocardiogram. A doctor or technician does this exam, also known as an EKG, to measure the electrical activity of your baby’s heart. EKGs can diagnose heart rhythm problems, called arrhythmias, and find parts of the heart that are too large or working too hard.

Chest X-ray. An X-ray of your baby’s chest can show the doctor signs of an enlarged or abnormally shaped heart. It can also tell whether your child’s lungs have fluid, which can be a sign of heart failure.

MRI and CT scans. Magnetic resonance imaging, or MRI, and computed tomography, or CT, scans are two more types of imaging tests that can provide detailed views of your baby’s heart.

Pulse oximetry. This measures the oxygen in your baby’s blood through a sensor on the end of their finger. If it shows too little, it could mean they have a heart problem.

Cardiac catheterization. If any of the previous tests show signs your baby has a congenital heart defect, their doctor may recommend a cardiac catheterization.


During the procedure, the doctor inserts a thin, flexible catheter, or tube, into a blood vessel in your baby’s thigh. The catheter is carefully threaded up to their heart.

Then the doctor injects a special dye through the catheter and uses X-ray equipment to see how the dye moves through the chambers of your baby’s heart.

If there are any problems with their heart or heart valves, the dye will show how the blood circulation is being affected.

Why Does Your Baby Need Testing?

In some people with congenital heart defects, signs of trouble are obvious at birth. Your baby might have bluish skin, lips, and fingernails. This is known as cyanosis.

Your child might also have a heart murmur, which is an “extra” sound their doctor hears through a stethoscope. It could be a sign of a heart valve defect.

Other symptoms such as troubled or rapid breathing, fatigue, and poor circulation are signs to see your child’s doctor.

Genes can play a role, too, so if you or someone in your family has a congenital heart defect, your baby is more likely to have one. Talk to your doctor about this.

Adults With Heart Defects

Some people with congenital heart defects don’t find out they have problems until later in life. Your doctor might find issues during a routine physical, or you might begin having chest pain or shortness of breath. Your doctor could also find it after you’ve had a heart test like an echocardiogram.

Whether your congenital heart defect shows up in infancy or adulthood, rest assured that your doctor has a range of options to diagnose it quickly.

WebMD Medical Reference



Mayo Clinic: “Congenital Heart Defects in Children: Tests and Diagnosis.”

American Heart Association: “Detection of a Heart Defect in the Fetus,” “Common Tests for Congenital Heart Defects,” “Genetic Counseling for Adults with Congenital Heart Defects.”

National Heart, Lung, and Blood Institute: “How Are Congenital Heart Defects Diagnosed?” “What Causes Congenital Heart Defects?” “What Are the Signs and Symptoms of Congenital Heart Defects?”

Mayo Clinic: “Congenital heart defects in children.”

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