Fetal echocardiography is an ultrasound test done during pregnancy to evaluate the heart of the unborn baby. It is usually done in the second trimester of pregnancy, at about 18 to 24 weeks.
Echocardiography assesses the structures and function of the heart. 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.
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