Which set of features is characteristic of physiological jaundice in a term newborn?

Answer: B. Does not appear before 24 hours, peaks at 48-72 hours, and resolves by about 1 week

Physiological jaundice

Physiological jaundice is a benign, self-limiting unconjugated hyperbilirubinaemia.

Typical course

• Affects 50-60% of term infants (and ~80% of preterm) in the first week.
• Does not appear before 24 hours.
• Peaks at 48-72 hours.
• Resolves by about 1 week.
• Phototherapy is needed in about 10%.

Mechanism

Increased red-cell breakdown, immature hepatic uptake and conjugation, and increased enterohepatic circulation, producing unconjugated bilirubin.

Why B

Physiological jaundice does not appear before 24 hours, peaks at 48-72 hours and resolves by ~1 week.

Why the others are wrong

It does not appear before 24 hours (or persist beyond 3 weeks - that is prolonged jaundice); it is unconjugated (not conjugated); it rarely needs exchange transfusion; and it occurs in term as well as preterm babies.