Evaluating a Baby’s Heart before Birth

Fetal Echocardiography uses sound waves (ultrasound) to evaluate the a baby’s heart for problems before it’s born. The test is done while the baby is still in the womb, usually during the second trimester of pregnancy (18 – 24 weeks).

The procedure is very similar to that of a pregnancy ultrasound. Dr. Klein and her staff perform the test by placing a clear, water-based gel on your belly and then moving a hand-held probe over the area. The probe sends out sound waves, which bounce off the baby’s heart and create a picture of the heart on a computer screen.

How to Prepare for the Test

No special preparation is needed.

How the Test Will Feel

The conducting gel may feel slightly cold and wet. You will not feel the ultrasound waves.

Why the Test Is Performed

Fetal echocardiography is done to detect a heart problem before a baby is born. It can provide a more detailed image of the baby’s heart than a regular pregnancy ultrasound can. It can show:

• Blood flow through the heart
• Heart rhythm
• Structures of the baby’s heart

The test may be done if:

• A sibling or other family member had a heart defect or heart disease

• A routine pregnancy ultrasound detected an abnormal heart rhythm or possible heart problem
in the unborn baby

• The mother has type 1 diabetes, lupus, or phenylketonuria

• The mother has rubella during pregnancy

• The mother has used medicines that can damage the baby’s developing heart (such as some epilepsy drugs and prescription acne medications)

• The amniocentesis revealed a chromosome disorder

Normal Results

Results are normal if the echocardiogram finds no problems in the unborn baby’s heart.

What Abnormal Results Mean

Abnormal results may be due to:

• A problem in the way the baby’s heart has formed (congenital heart disease)

• A problem with the way the baby’s heart works

• Heart rhythm disturbances (arrhythmias)

The test may need to be repeated.


There are no known risks to the mother or unborn baby.

Things to Consider

Some heart defects cannot be seen before birth, even with fetal echocardiography. These include small holes in the heart or mild valve problems. Also, it may not be possible to see every part of the blood vessels leading into or out of the baby’s heart. Therefore, problems in these areas may go undetected. If we find a problem in the structure of the heart, a detailed ultrasound may be done to look for other problems with the developing baby.

Ready to Learn More?

If you’d like to learn more about fetal echocardiography or any of the other diagnostic testing offered at Heart to Heart Pediatric Cardiology, CONTACT US today.