What is fetal echocardiography?
Fetal echocardiography is an ultrasound test performed during pregnancy to evaluate the heart of the unborn baby. Ultrasound uses sound waves to take pictures of the heart.
There is no radiation exposure and no known risk with this type of test.
Echocardiography assesses the heart’s structures and function. Fetal echocardiography can help detect fetal heart abnormalities before birth, allowing for faster medical or surgical intervention once the baby is born.
This improves the chance of survival and lowers the rate of complications after delivery for babies with serious heart defects.
When is a fetal echocardiogram necessary?
It is not necessary for all fetuses to receive an echocardiogram. The prenatal ultrasound tests that are done prior to birth can give information about whether the fetal heart has developed with all four chambers. Most unborn babies do not require any further testing. Situations in which a fetal echocardiogram may be necessary include, but are not limited to, the following:
- If a sibling was born with a congenital (present at birth) heart defect
- A family history of congenital heart disease (such as parents, aunts or uncles, or grandparents)
- A chromosomal or genetic abnormality discovered in the fetus
- If a mother has taken certain medications that may cause congenital heart defects, such as anti-seizure medications or prescription acne medications
- If the mother has abused alcohol or drugs during pregnancy
- If a mother has diabetes, phenylketonuria, or a connective tissue disorder such as lupus
- If the mother has had rubella during pregnancy
- A routine prenatal ultrasound has discovered possible heart abnormalities
Fetal echocardiograms are usually performed in the second trimester of pregnancy, between 18 and 24 weeks gestation. The test is sometimes done earlier in pregnancy, but will be repeated later to confirm any findings.
How is a fetal echocardiogram performed?
A fetal echocardiogram is performed by a pediatric cardiologist or a maternal fetal specialist (also called a perinatologist) who is specially trained. The test is done in a private room while the woman is lying in a comfortable bed. It is painless and takes from 20 to 45 minutes. It is fine for a family member to stay in the room during the test. Gel is applied to the abdomen and the ultrasound transducer (like a microphone) glides over the gel on the abdomen to create the image. During the test the transducer probe will be moved around to obtain images of different locations and structures of the fetal heart. Techniques sometimes used to obtain detailed information about the fetal heart include the following:
This technique is used to “see” the actual structures and motion of the heart structures. A 2-D 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 the various heart structures at work and evaluate them.
This Doppler 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 can detect abnormal blood flow within the heart, which can indicate such problems as a communication 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 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.