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Tetralogy of Fallot

What is it?

  • About 40,000 babies are born in the United States each year with a heart that is not normal. Some 4,000 of these babies have a heart defect called tetralogy (tet-rall-o-g) of Fallot (fuh-low). It is also called "TOF." Babies with TOF may be called "blue babies" because their skin has a bluish color. This is because they are not getting enough oxygen.
  • There are 4 problems in the heart with TOF:
    • There is a hole between the lower right and lower left parts of the heart. This is called a ventricular (ven-trik-u-ler) septal (sep-tull) defect (VSD).
    • The aorta (a-or-tuh) is a major artery that sends blood through the body. In TOF, the aorta is pushed out of place.
    • It is harder for the heart to pump blood to the lungs.
    • The lower right part of the heart is larger than normal.


It is not known what causes TOF. A family history of TOF may cause your child to have this problem. TOF may be caused by the mother using certain medications or taking drugs early in her pregnancy. Or a pregnant woman may have had an infection while her baby's heart was forming. The heart forms during the first trimester of pregnancy.

Signs and Symptoms:

Most children with TOF have slow growth, tiredness, or trouble breathing. Another sign may be blue skin, lips, and nailbeds. Your child may be fussy, look pale, and have problems gaining weight.


  • Your child may need to be put in the hospital for tests and treatment. Open heart surgery may need to be done. When your child has surgery is based on your child's age, weight, health, and the heart problem.
  • Antibiotic (an-ti-bi-ah-tik) medicine may be needed before your child has dental work. This may be needed to keep your child from getting a heart infection. Oxygen may be needed to help your child's breathing.

Care Agreement

You have the right to help plan your child's care. To help with this plan, you must learn about your child's health condition and how it may be treated. You can then discuss treatment options with your child's caregivers. Work with them to decide what care may be used to treat your child.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.