What bilirubin level range is expected at 24 hours of life?

• A. 2-6 mg/dL
• B. 0-1 mg/dL
• C. 6-12 mg/dL
• D. 10-15 mg/dL

Answer: (A)

Newborn bilirubin patterns reflect the liver’s ongoing maturation in conjugating and eliminating bilirubin. Physiologic jaundice is the normal rise in unconjugated bilirubin that occurs after birth due to increased bilirubin production and immature liver enzymes. By about 24 hours of life, a term infant is typically expected to have a total bilirubin level in the range of roughly 2 to 6 mg/dL. This range fits the early phase of physiologic jaundice, before the typical peak that occurs around day 3 to 5. Levels much lower than this at 24 hours aren’t typical for physiologic jaundice, and levels in the 6–12 mg/dL (or higher) range at 24 hours would be more concerning for pathologic jaundice or other causes and would prompt closer evaluation. So the 2–6 mg/dL range is the normal expectation at 24 hours.