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Environmental Public Health Tracking: Transposition of the Great Arteries Data

A birth defect is a problem that happens while the baby is developing in the mother's body. Most birth defects happen during the first three months of pregnancy. A birth defect may affect how the body looks, works, or both.

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Transposition of the great arteries is one type of birth defect. Review the FAQs below for more information about transposition of the great arteries.

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Transposition of the great arteries (TGA) is a heart condition that is present at birth and is often called a congenital heart defect. TGA might also be referred to as transposition of the great vessels, but TGA is the more common term. TGA occurs when the two main arteries going out of the heart, the pulmonary artery and the aorta, are switched in position, or transposed.

Researchers estimate about 1,153 babies in the United States are born with TGA each year. In other words, about 1 out of every 3,413 babies born in the United States are born with TGA each year.*

*Mai CT, Isenburg JL, Canfield MA, Meyer RE, Correa A, Alverson CJ, Lupo PJ, Riehle‐Colarusso T, Cho SJ, Aggarwal D, Kirby RS. "National population‐based estimates for major birth defects, 2010–2014." Birth Defects Research. 2019; 111(18): 1420-1435.

The cause of TGA is unknown. CDC (Centers for Disease Control and Prevention) works with many researchers to study risk factors that can increase the chance of having a baby with TGA. Learn more about causes and risk factors on the CDC's Facts about TGA page.

There is no known way to prevent this defect, but some of the problems experienced later in life can be prevented or lessened if the defect is found early. Mothers can take steps before and during pregnancy to have a healthy pregnancy. Steps include taking a daily multivitamin with folic acid (400 micrograms), not smoking, and not drinking alcohol during pregnancy. Learn more about prevention and treatment on the CDC's Facts about TGA page.

Last revised January 5, 2023