Newborn Screening for Metabolic and Sickle Cell Disorders Program

Screening: Special Cases

Infants in the neonatal intensive care unit (NICU) have so many critical needs that their newborn screening test may be overlooked. It is advisable to establish a protocol to be sure that this screening is done.

Transferred Infants

In the event of transfer to another facility shortly after birth or before screening has been accomplished, the transferring facility must ensure that the next facility is aware of the need for screening. (Remember that the responsible party for screening is the one who attended the delivery of the newborn!) Hospitals transferring a sick neonate to a NICU should document in the medical record whether the first newborn screen has been done. The receiving NICU should also note whether newborn screening has been done. If not, the neonate should have a newborn screen done within the first 7 days of life and this should be documented in the record and reported to the transferring hospital.

Transfusions

Even small transfusions may invalidate screening test results. If a newborn is to receive a transfusion, it is critical to collect a specimen prior to the transfusion. A second sample for newborn screening should be collected one week after the last transfusion and a third sample two months post transfusion. Unscreened infants transfused before admission to the NICU should be screened regardless, but will need re-screening 2 months post transfusion.

Critically ill and Premature Infants

A critically ill or premature infant should receive the first screen before seven days of age. These infants may have persistent abnormalities in newborn screening test results without actually having a metabolic disorder or hemoglobinopathy. Prematurity is associated with physiological elevation of 17-hydroxyprogesterone (17-OHP) and reduction of thyroxine (T4). Total parenteral nutrition (TPN) may cause a false positive test for several of the disorders. Additionally, a normal screen in an infant who has insufficient enteral intake does not rule out metabolic disease.

Premature babies may have to be retested several times because of immature enzyme systems or thyroid functioning. It may be necessary to monitor their progress to be certain they reach normal levels. An abnormal screening test result should be noted in the chart and if the premature/ill infant shows clinical signs consistent with the disorder, confirmatory testing should be immediately done. If the child shows no signs of the disorder, repeat screening should be done by one month of age or at discharge (whichever occurs first), or when requested by the newborn screening system. A tickler system is advised to assure appropriate follow-up.

Clinical And Laboratory Standards Institute (CLSI) recently released Newborn Screening for Preterm, Low Birth Weight, and Sick Newborns; Approved Guideline. These guidelines are under review by the Georgia Newborn Screening Program for adoption into existing protocols and procedures.

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