Physiologic jaundice in a newborn typically appears when?

• A. Immediately at birth
• B. After 3-4 weeks
• C. 2-3 days
• D. After 24 hours of life and resolves by 1-2 weeks

Answer: (D)

Physiologic jaundice occurs because a newborn’s liver is still maturing and not yet efficient at converting unconjugated bilirubin into a water-soluble form for excretion. With the high turnover of fetal red blood cells after birth, bilirubin levels rise, but the immature hepatic enzyme system (glucuronosyltransferase) can’t process it quickly enough.

This type of jaundice typically becomes noticeable after the first 24 hours of life. In term infants, bilirubin usually peaks around day 3–5 and then declines, returning to normal within about 1–2 weeks. In preterm babies, it may last a bit longer, but the classic pattern is a rise starting after the first day and resolution by the end of the second week or so.

If jaundice appears within the first 24 hours or lasts much longer than 1–2 weeks (especially with accompanying red flags like poor feeding, dehydration, a very high level of bilirubin, or signs of illness), it’s more likely to be a pathologic process and warrants evaluation.