 Congenital heart disease occurs in about 1 of all live births. Cyanotic cardiac lesions in particular are at risk for significant mortality and morbidity because of their reduced ability to provide adequate oxygenation to the body and the brain. Many experts believe that to have adequate oxygen carrying capacity that these infants should ideally have a hemoglobin level greater than 13 gdL. Many of these patients require blood transfusions prior to surgery to provide adequate oxygenation. The cause for this is likely multifactorial including normal neonatal physiology, frequent lab draws, and co-morbidities. Although rare, the morbidity due to transfusions can be devastating to this population including transmitted infections, transfusion reactions, extra hospitalizations, and antigen sensitization that would complicate heart transplant if needed. 