Fetal Echocardiography

What is fetal echocardiography?

Fetal echocardiography is an ultrasound test done during pregnancy to evaluate the heart of the unborn baby.

Echocardiography assesses the heart's structures and function. A small probe called a transducer (similar to a microphone) is placed on the mother's abdomen and sends out ultrasonic sound waves at a frequency too high to be heard. When the transducer is placed in certain locations and at certain angles, the ultrasonic sound waves move through the mother's and baby's skin and other body tissues to the baby's heart tissues, where the waves bounce (or "echo") off of the heart structures. The transducer picks up the reflected waves and sends them to a computer. The computer interprets the echoes into an image of the heart walls and valves.

Fetal echocardiography can help detect heart abnormalities before birth, allowing for faster medical or surgical intervention once the baby is born. This improves the chance of survival after delivery for babies with severe heart defects.

When is a fetal echocardiogram necessary?

It's not necessary for all women to have a fetal echocardiogram during pregnancy. The prenatal ultrasound tests that are done routinely prior to birth can give information about whether the fetal heart has developed 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 antiseizure medications or prescription acne medications

• If the mother has abused alcohol or drugs during pregnancy

• If a mother has diabetes, lupus, phenylketonuria, or a connective tissue disease

• If the mother has had rubella during pregnancy

• A routine prenatal ultrasound has discovered possible heart abnormalities

• A routine prenatal ultrasound has identified other congenital (present at birth) anomalies, such as kidney, brain or bone abnormalities.

Fetal echocardiograms are usually done in the second trimester of pregnancy, at about 18 to 24 weeks.

How is a fetal echocardiogram done?

A fetal echocardiogram is done by a pediatric cardiologist who is specially trained. The test is typically done by placing a probe over the mother's abdomen to visualize the fetal heart.

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:

• 2-D (two-dimensional) echocardiography. 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 doctor to see the various heart structures at work and evaluate them.

• Doppler echocardiography. This Doppler technique is used to measure the speed of blood flow through the heart's chambers and valves. Also, Doppler can detect abnormal blood flow within the heart, which can indicate such problems as an opening between chambers of the heart, or a problem with one or more of the heart's four valves. Color Doppler is used to determine the direction of blood flow in the baby's heart.

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 after delivery for babies with serious heart defects. Other tests or procedures that may be needed include the following:

• Additional ultrasounds or echocardiograms. Tests done to confirm the diagnosis, follow fetal growth, and monitor fetal well-being.

• Amniocentesis. A test done to identify the presence of chromosomal and genetic disorders and certain birth defects. The test involves inserting a needle through the abdominal and uterine wall into the amniotic sac to retrieve a sample of amniotic fluid.

• Genetic counseling. Providing an assessment of heritable risk factors and information to patients and their relatives concerning the consequences of a disorder, the probability of developing or transmitting it, and ways in which it can be prevented, treated, and managed.