Transposition of the great arteries (TGA) occurs when the main artery that carries blood to the lungs (pulmonary artery) and the main artery that carries blood to the rest of the body (aorta) are switched. This means that blood with low levels of oxygen pumps throughout the body, damaging the organs.

TGA – Causes and Diagnosis

TGA is diagnosed by an electrocardiogram (ECG) and echocardiogram performed shortly after birth. If further evaluation of the heart is needed, a cardiac MRI or cardiac catheterization may be performed.

A baby born with TGA may have the following symptoms:

  • Appear bluish in color (cyanosis)
  • Have difficulty breathing

The main cause of TGA is unknown, but the defect may be associated with a genetic disorder. A baby with TGA and a chromosomal or genetic condition usually has physical and developmental problems, too. During pregnancy, either a chorionic villus sampling (CVS) or an amniocentesis can test for many chromosomal conditions.

If your baby's congenital heart defect is related to a chromosome abnormality or a genetic syndrome, a genetic counselor can discuss the risk of having another baby with the same condition.

Read our Patient Guidebook on TGA

Our Patient Guidebooks provide additional information about the conditions we treat. They are not diagnoses and should never be used instead of medical advice.

Care Providers

The University of Maryland Children's Heart Program team that treats TGA includes a pediatric cardiac surgeon, pediatric cardiologists, pediatric and neonatal intensive care doctors and nurses, pediatric cardiac anesthesiologists, cardiac operating room staff, cardiac nurses and many others with expertise in providing this specialized cardiac care.

If TGA is diagnosed while you are pregnant, you will see a maternal fetal medicine specialist who will treat you during your pregnancy.

Treating TGA

Babies who have TGA will typically have surgery for an arterial switch the first week of life. An arterial switch will help establish normal blood flow by connecting the aorta to the left ventricle and the pulmonary artery to the right ventricle. Then the coronary arteries can be properly attached.

Your baby will remain in the pediatric intensive care unit (PICU) up to 2 weeks and is released when he or she is feeding well.

After the arterial switch surgery, narrowing in the aorta, pulmonary arteries or where the coronary arteries are reattached to the aorta may develop at any stage in your child's life. If the narrowing is mild, it may be monitored with echocardiograms. Sometimes, these narrowed areas can be fixed by using a balloon or a stent in the cardiac catheterization laboratory. Other times, repeat surgery is needed.

Contact Us

  • To learn more about Maternal Fetal Heart medicine, please call 410-328-3865.
  • To make an appointment with a Children's Heart Program physician, please call 410-328-4348.