Timing of Specimen Collection
A filter paper newborn screening specimen should be collected:
- between 24 and 48 hours of age,
- prior to transfer,
- prior to transfusion,
- prior to discharge, whichever comes first
Newborn screening tests and cutoffs are based on specimens collected between 24-48 hours of age. If the baby is to be discharged, transferred, or transfused before 24 hours of age, a dried blood spot filter paper specimen should be collected PRIOR to discharge, transfer, or transfusion.
Early discharges, transfers, and transfusions increase the potential for a dangerous delay in the newborn screening process and require significant effort by hospital staff, physicians, and the SDNSP to locate the infant for collection of the newborn screening.
Specimen Collected Early (< 24 hours)
If the initial specimen is collected before 24 hours of age, a second specimen must be collected within 2 weeks of age.
A specimen should be collected as close as possible to discharge and no later than 7 days of life unless a transfusion is imminent. The appropriate strategy is to always collect a newborn screening sample immediately before any transfusions, regardless of the infant's age.
Red blood cell (RBC) transfusions interfere with the interpretation of some newborn screening results. The appropriate strategy is to always collect a newborn screening sample immediately before any transfusions, regardless of the infant's age. Since red blood cells and plasma transfusions can cause false-negative results, post-transfusion follow-up at the appropriate time is essential.
Whenever possible, the newborn screen specimen should be collected prior to a transfusion of blood products, even if less than 24 hours of age.
- If the infant was transfused at the time of collection, a follow-up filter paper specimen must be collected at least 8 weeks after the last transfusion.
When possible, the originating hospital should draw a newborn screening specimen before transferring the infant to another hospital. Transfer information should be documented in the "Certifier's Worksheet" for Birth Certificate filing. This information will assist with follow-up if the newborn screening was not done prior to transfer.
Out of Hospital Births
The parents, guardians, or custodians of each infant are responsible for having the blood spot specimen collected.