Newborn screening for metabolic disorders is typically performed using which method?

• A. Hearing screen
• B. Heel-stick blood sample
• C. Urine dipstick
• D. Cord blood gas

Answer: (B)

Newborn screening for metabolic disorders relies on collecting a small blood sample that can be analyzed for many conditions with one test. A heel-stick blood sample on a filter paper card creates dried blood spots, which are ideal because they provide enough material for broad metabolic testing, often using tandem mass spectrometry to detect amino acid, organic acid, and fatty acid oxidation disorders. The sample is typically drawn after about 24 hours of life to ensure metabolites are detectable, and the dried spots are easy to transport and store for lab analysis. The other options serve different purposes: a hearing screen checks auditory function, a urine dipstick screens urine for hydration and common infections or issues but not the wide metabolic panel, and cord blood gas evaluates the newborn’s oxygenation and acid-base status at birth, not metabolic disorders.