Postpartum Newborn Laboratory Tests

Screening Tests

• Blood glucose testing identifies hypoglycemia, which can cause neurological damage if left untreated, especially in infants with risk factors such as maternal diabetes, prematurity, or low birth weight 1
• Blood typing determines the infant's blood group and Rh status to identify potential incompatibilities with maternal blood type that could lead to hemolytic disease of the newborn 1, 2
• DAT detects antibody-coated red blood cells in the infant's circulation, indicating maternal-fetal blood group incompatibility that may lead to hemolytic disease and hyperbilirubinemia 1, 2
• Transcutaneous bilirubin provides a non-invasive screening method to detect jaundice and estimate serum bilirubin levels, helping to identify infants at risk for hyperbilirubinemia without blood sampling 3
• Serum bilirubin measures the actual concentration of bilirubin in the blood to diagnose hyperbilirubinemia and determine the need for phototherapy or exchange transfusion to prevent kernicterus 3, 4
• Hearing screening identifies congenital hearing loss early, allowing for prompt intervention to prevent delays in speech, language development, and learning that could affect quality of life 5, 6
• CHD screening through pulse oximetry detects critical congenital heart defects that might otherwise go undetected at birth, allowing for timely intervention to prevent sudden cardiac decompensation and death 7, 8
• Blood spot testing screens for numerous metabolic, endocrine, and genetic disorders that, if identified early, can be treated to prevent intellectual disability, physical disability, or death 2, 9

Important Considerations

• The American Academy of Pediatrics recommends that the timing of collection is critical; some tests (like metabolic screening) may need to be repeated if performed before 24 hours of milk feeding 1
• Results of these screenings should be reviewed before discharge and appropriate follow-up arranged for abnormal findings, as recommended by the American Academy of Pediatrics 7, 8
• Early identification through these screenings allows for timely intervention, significantly improving outcomes and quality of life for affected infants, according to the American Academy of Family Physicians and the American College of Medical Genetics and Genomics 5, 9