Blood transfusions are known to affect the results of hemoglobinopathy and galactosemia screens and may affect other screens as well (Reed, 2000; Korson, 1990).
If a blood transfusion is anticipated, whenever possible, collect a blood spot card prior to the transfusion regardless of the baby’s age.
If the baby is less than 24 hours old when the card is collected, the NBS Laboratory will request, through the baby’s physician/midwife, that a repeat card be collected by two weeks (14 days) of age.
If a blood spot card is not collected prior to the transfusion, collect at 24 – 48 hours of age. The NBS Laboratory will request, through the baby’s physician/ midwife, that two repeat cards be collected, one at three weeks (21 days) and one at four months (120 days) after the date of the transfusion.