Fetal echocardiography is a test similar to an ultrasound. This exam allows your doctor to better see the structure and function of your unborn child’s heart. It’s typically done in the second trimester, between weeks 18 to 24.

The exam uses sound waves that “echo” off the structures of the fetus’s heart. A machine analyzes these sound waves and creates a picture, or echocardiogram, of their heart’s interior. This image provides information on how your baby’s heart formed and whether it’s working properly.

It also enables your doctor to see the blood flow through the fetus’s heart. This in-depth look allows your doctor to find any abnormalities in the baby’s blood flow or heartbeat.

Not all pregnant women need a fetal echocardiogram. For most women, a basic ultrasound will show the development of all four chambers of their baby’s heart.

Your OB-GYN may recommend that you have this procedure done if previous tests weren’t conclusive or if they detected an abnormal heartbeat in the fetus.

You may also need this test if:

  • your unborn child is at risk for a heart abnormality or other disorder
  • you have a family history of heart disease
  • you’ve already given birth to a child with a heart condition
  • you’ve used drugs or alcohol during your pregnancy
  • you’ve taken certain medications or been exposed to medications that can cause heart defects, such as epilepsy drugs or prescription acne drugs
  • you have other medical conditions, like rubella, type 1 diabetes, lupus, or phenylketonuria

Some OB-GYNs perform this test. But usually an experienced ultrasound technician, or ultrasonographer, performs the test. A cardiologist who specializes in pediatric medicine will review the results.

You don’t need to do anything to prepare for this test. Unlike other prenatal ultrasounds, you won’t need to have a full bladder for the test.

The test can take anywhere from 30 minutes to two hours to perform.

This test is similar to a routine pregnancy ultrasound. If it’s performed through your abdomen, it’s called an abdominal echocardiography. If it’s performed through your vagina, it’s called a transvaginal echocardiography.

Abdominal echocardiography

An abdominal echocardiography is similar to an ultrasound. An ultrasound technician first asks you to lie down and expose your belly. They then apply a special lubricating jelly to your skin. The jelly prevents friction so that the technician can move an ultrasound transducer, which is a device that sends and receives sound waves, over your skin. The jelly also helps transmit the sound waves.

The transducer sends high-frequency sound waves through your body. The waves echo as they hit a dense object, such as your unborn child’s heart. Those echoes are then reflected back into a computer. The sound waves are too high-pitched for the human ear to hear.

The technician moves the transducer all around your stomach to get images of different parts of your baby’s heart.

After the procedure, the jelly is cleaned off your abdomen. You’re then free to return to your normal activities.

Transvaginal echocardiography

For a transvaginal echocardiography, you’re asked to undress from the waist down and lie on an exam table. A technician will insert a small probe into your vagina. The probe uses sound waves to create an image of your baby’s heart.

A transvaginal echocardiography is typically used in earlier stages of pregnancy. It may provide a clearer image of the fetal heart.

There are no known risks associated with the echocardiogram because it uses ultrasound technology and no radiation.

During your follow-up appointment, your doctor will explain the results to you and answer any questions. Generally, normal results mean your doctor found no cardiac abnormality.

If your doctor found an issue, such as a heart defect, rhythm abnormality, or other problem, you may need more tests, such as a fetal MRI scan or other high-level ultrasounds.

Your doctor will also refer you to resources or specialists who can treat your unborn child’s condition.

You may also need to have an echocardiograph done more than once. Or you may need additional testing if your doctor thinks something else could be wrong.

It’s important to remember that your doctor can’t use the results of echocardiography to diagnose every condition. Some problems, such as a hole in the heart, are difficult to see even with advanced equipment.

Your doctor will explain what they can and can’t diagnose using the test results.

Abnormal results from fetal echocardiography can be inconclusive or require that you get more testing to find what’s wrong. Sometimes problems are ruled out and no further testing is needed. Once your doctor diagnoses a condition, you can better manage your pregnancy and prepare for delivery.

Results from this test will help you and your doctor plan treatments your baby may need after delivery, such as correctional surgery. You can also get support and counseling to help you make good decisions during the remainder of your pregnancy.