In newborns, unconjugated hyperbilirubinemia with normal liver function is most consistent with which condition?

• A. Breast milk jaundice
• B. Physiologic jaundice
• C. Hepatocellular jaundice
• D. Obstructive jaundice

Answer: (B)

Physiologic jaundice is the best fit here. After birth, a newborn’s red blood cells turnover rapidly, producing a lot of bilirubin, while the liver’s ability to conjugate bilirubin is immature. This leads to a rise in unconjugated (indirect) bilirubin even though the liver itself isn’t damaged, so liver function tests remain normal. The typical pattern fits: jaundice appears after the first day, peaks around day 3–4 in term infants, and resolves within a week or two as the liver matures. Other causes would usually show abnormalities: hepatocellular jaundice would raise liver enzymes and often involve conjugated bilirubin, while obstructive jaundice would present with cholestasis and conjugated bilirubin. Breast milk jaundice can be similar but tends to start later and can persist longer, making physiologic jaundice the more likely explanation in this scenario.