Erythrocyte transfusion can impair detection of sickle-cell disease, galact
osemia, or biotinidase deficiency with newborn screening. We report on 4 in
fants with SCD in whom delayed diagnosis was associated with neonatal trans
fusion. In 2 cases, the initial newborn screening showed no hemoglobin S. I
n no case was the recommended screening greater than or equal to 120 days f
rom the last transfusion obtained. Two children had significant SCD-related
morbidity before diagnosis.