Tricuspid atresia is a heart defect present at birth (congenital) in which one of the valves (tricuspid valve) between two of the heart's chambers isn't formed. Instead, there's solid tissue between the chambers.
If your baby is born with tricuspid atresia, blood can't flow through the heart and into the lungs to pick up oxygen as it normally would. The result is the lungs can't supply the rest of your baby's body with the oxygen it needs. Babies with tricuspid atresia tire easily, are often short of breath and have blue-tinged skin.
Tricuspid atresia is treated with surgery. Most babies with tricuspid atresia who have surgery will live well into adulthood, though follow-up surgeries are often needed.