Our guide to specialized cardiac testing for expectant parents

Prepared by the Committee on Congenital Cardiac Defects, Council on Cardiovascular Disease in the Young, American Heart Association

What is fetal echocardiography?

Fetal echocardiography is a test using sound waves (ultrasound) to study the structure of your baby’s heart before birth. Your obstetrician may obtain a limited view of your baby’s heart during a routine pregnancy ultrasound. However, a fetal echocardiogram is a very detailed evaluation of your baby’s heart by a specialist in fetal echocardiography. There are no known risks to the mother or the fetus.

Who needs a detailed fetal echocardiogram?

Some pregnant women are at increased risk of giving birth to a baby with congenital heart disease. They should be considered for referral for a specialized fetal echocardiogram. Indications include the following:

• a family history of congenital heart disease -- the risk if a previous child has congenital heart disease is about 1/50, and is about 1/10 to 1/20 if the parent has congenital heart disease
• an abnormal fetal heart rhythm
• fetal heart abnormalities detected during a routine pregnancy ultrasound scan
• abnormality of another major organ system
• insulin-dependent (type 1) diabetes mellitus
• exposure to some drugs in early pregnancy, for example, some anti-epileptic drugs can damage the developing heart
• abnormal amniocentesis

When can a fetal echocardiogram be performed?

The heart motion can be seen from about six weeks of gestation. However, details of heart structure cannot be seen until

• 14 weeks gestation using scanning through the vagina.
• 18 weeks gestation using imaging through the abdomen.

Sometimes, repeat examinations are needed.

Who should do a fetal echocardiogram?

A limited cardiac evaluation is possible during regular obstetric scanning and is appropriate for women at low risk. However, some women should have a detailed fetal echocardiogram performed by a physician who is specially trained in fetal cardiac evaluation. They include women at increased risk of having a baby with a congenital heart disease or in whom a cardiac malformation is suspected by the initial ultrasound study.

What conditions can be identified?

• abnormalities of cardiac structure (congenital heart disease)
• cardiac rhythm disturbances (or arrhythmias)
• disorders of cardiac function

Are there limitations of fetal echocardiography?

Some heart abnormalities are not detectable prenatally even with a detailed expert examination. These tend to be minor defects, such as small holes in the heart, or mild valve abnormalities. In addition, some cardiac defects do not become evident until after birth.

The fetal echocardiogram focuses on the heart. The fetal echocardiographer may not see defects in other parts of the fetus. 

What are the implications of fetal echocardiography?

• The detection of a heart defect increases the risk of finding other malformations in the child. A detailed ultrasound of the rest of the fetus is necessary. Also, amniocentesis to test the chromosomes may be recommended.
  
• A serious or even life-threatening heart abnormality may be identified. It may have a significant impact on the future of the child. You will want to discuss this with your doctor.
  
• Currently only cardiac rhythm disturbances are being treated before birth. In the future a number of structural cardiac defects may be treated before birth.
  
• In many cases of congenital heart disease diagnosed prenatally, it is safest to deliver the pregnancy at, or near, the center at which postnatal treatment will take place. This is especially true if surgery will be required soon after birth.

Who can counsel or advise me about cardiac findings?

• A perinatalogist or obstetrician can advise you about the management of your pregnancy.
  
• A pediatric cardiologist is in the best position to give advice about the outlook for your child’s heart problem.
  
• A geneticist can provide information about a fetus with an associated genetic syndrome, if present, and advise about future pregnancies.
  
• A cardiac surgeon can give details about surgical procedures that may be needed.
  
• A nurse, who is familiar with heart disease in children, can provide information about caring for a child with congenital heart disease.

©1999, American Heart Association.

This content is reviewed regularly. Last updated 10/14/08.