Which statement accurately describes physiologic jaundice in newborns?

• A. It begins within the first 24 hours of life
• B. It peaks at day 3-5 and resolves by about one week
• C. It is always pathologic
• D. It is caused by direct bilirubin accumulation

Answer: (B)

Physiologic jaundice arises because a newborn’s liver is immature at birth and cannot conjugate bilirubin efficiently yet. This causes a temporary rise in unconjugated bilirubin. The typical pattern is that jaundice does not appear before 24 hours, climbs to a peak around days 3 to 5, and then declines, usually resolving by about one week in term infants (a bit later in preterm babies). This timing and the fact that the elevated bilirubin is unconjugated help distinguish physiologic jaundice from pathologic causes, which can start earlier or involve direct (conjugated) bilirubin.