Fetal Echocardiography

What is a fetal echocardiogram?

A fetal echocardiogram (echo) is an ultrasound test that focuses on the heart of a developing fetus. When congenital heart defects (CHDs) are detected before birth, a fetal echo improves the chance of survival; it allows doctors to plan for medical or surgical intervention before and after delivery.

How does a fetal echocardiogram work?

A fetal echo is performed by a sonographer and fetal cardiologist. The test uses a small probe called a transducer (like a microphone) that's placed on the pregnant patient's abdomen and sends out ultrasonic sound waves at a frequency too high to be heard.

When the transducer is placed in specific locations and at certain angles on the pregnant person’s abdomen, the sound waves move through the skin and other tissue to the fetus’ heart tissues, where the waves bounce (or "echo") off the heart structures.
The transducer picks up the reflected waves and sends them to a computer, which processes the waves to create a real-time image of the fetal heart. This image allows healthcare professionals to see the structure and function of the fetal heart chambers, valves, and blood vessels.

Techniques sometimes used to obtain detailed information about the fetal heart include:

2D (2-dimensional) echocardiography: This technique is used to "see" the actual structures and motion of the heart structures. A 2D echo view appears cone-shaped on the monitor, and the real-time motion of the heart's structures can be observed. This enables the physician to see and evaluate the various heart structures at work.
Doppler echocardiography: This technique is used to measure and assess the flow of blood through the heart’s chambers and valves. The amount of blood pumped out with each beat is an indication of the heart's functioning. Also, Doppler echocardiography can detect abnormal blood flow within the heart, which can indicate such problems as an opening between chambers of the heart, a problem with one or more of the heart's four valves, or a problem with the heart's walls.
Color Doppler: Color Doppler is an enhanced form of Doppler echocardiography. With color Doppler, different colors are used to designate the direction of blood flow. This simplifies the interpretation of the Doppler images.

When is a fetal echocardiogram necessary?

Not all pregnant people need an echocardiogram. Routine prenatal ultrasounds can provide information about whether the fetal heart has developed normally, and most pregnant people don’t need further testing.

A fetal echocardiogram may be necessary or recommended when:

Obstetric ultrasound showed a suspected heart problem
Obstetric ultrasound showed a problem outside of the heart that increases risk of a heart problem
Genetic testing showed an abnormality that increases risk of a heart problem
If the pregnant person has medical conditions that increase the risk of a heart problem
If the pregnant person takes certain medications that can increase the risk of a heart problem
If there is a family history of congenital heart defects

Fetal echocardiograms are usually performed at 18 weeks or after for the best visualization of the heart.