Screening Tests for Newborns

Screening recommendations for newborns vary by clinical context and regulatory requirements. In the United States, the Health Resources & Services Administration recommends screening for all disorders included in the Recommended Uniform Screening Panel.

Blood typing is indicated when the mother has type O or Rh-negative blood or when minor blood antigens are present, because hemolytic disease of the newborn is a risk.

All neonates are evaluated for jaundice throughout the hospital stay and before discharge. The risk of hyperbilirubinemia is assessed using risk criteria, measurement of bilirubin, or both. Bilirubin can be measured transcutaneously or in serum. Many hospitals screen all neonates and use a predictive nomogram to determine the risk of extreme hyperbilirubinemia. Follow-up is based on age at discharge, predischarge bilirubin level and/or rate of bilirubin rise from one determination to another, and risk of developing jaundice.

Many government organizations require testing for specific inherited diseases, including phenylketonuria, tyrosinemia, biotinidase deficiency, homocystinuria, maple syrup urine disease, galactosemia, congenital adrenal hyperplasia, sickle cell disease, and hypothyroidism. Some organizations also include testing for cystic fibrosis, disorders of fatty acid oxidation, other organic acidemias, severe combined immunodeficiency, spinal muscular atrophy, and some lysosomal disorders (eg, mucopolysaccharidoses, Pompe disease).

HIV screening is required by some government organizations and is indicated for children of mothers known to be HIV-positive or those engaging in HIV high-risk behaviors.

Toxicology screening is indicated when any of the following are present: maternal history of drug use, unexplained placental abruption, unexplained premature labor, poor prenatal care, or evidence of drug withdrawal in the neonate.

Screening for critical congenital heart disease (CCHD) using pulse oximetry is part of routine newborn assessment. Previously, newborns were screened for CCHD by prenatal ultrasonography and by physical examination, but this approach failed to identify many cases of CCHD, which led to increased morbidity and mortality. The screening is done when infants are ≥ 24 hours old and is considered positive if

• Any oxygen saturation measurement is < 90%.

• The oxygen saturation measurements in both the right hand and foot are < 95% on 3 separate measurements taken 1 hour apart.

• There is > 3% absolute difference between the oxygen saturation in the right hand (preductal) and foot (postductal) on 3 separate measurements taken 1 hour apart.

Any infant with a positive screen should have additional testing, including chest x-ray, electrocardiography, and echocardiography. The infant’s pediatrician should be notified, and the infant may need to be evaluated by a cardiologist.

Hearing screening varies by state. Hearing loss is one of the most frequently occurring birth defects. About 2 to 3/1000 infants are born with moderate, profound, or severe hearing loss (1). Hearing loss is even more common among infants admitted to an intensive care unit at birth. Currently, some government organizations screen only high-risk neonates (se table High-Risk Factors for Hearing Deficits in Neonates); others screen all neonates. Initial screening often involves using a handheld device to test for echoes produced by healthy ears in response to soft clicks (otoacoustic emissions); if this test is abnormal, auditory brain stem response (ABR) testing is done. Some institutions use ABR testing as an initial screening test. Further testing by an audiologist may be needed.