When is jaundice in a newborn considered normal or physiologic?

Jaundice in a newborn is considered normal or physiologic when it appears after 48 hours of life and resolves within one to two weeks. This timing is crucial because early onset jaundice, particularly within the first 24 hours, can be indicative of pathological processes, such as hemolytic disease or other serious conditions. The accumulation of bilirubin that causes jaundice usually peaks around days 3 to 5, which aligns with the option that states jaundice is physiologic after this timeframe.

This physiological jaundice is primarily due to the newborn's immature liver function and increased breakdown of red blood cells after birth, which leads to a transient rise in indirect (unconjugated) bilirubin. Monitoring is essential, but in most cases of physiologic jaundice, the bilirubin levels will peak and then decline without intervention.

Thus, physiologic jaundice typically appears after 48 hours of life and is observed to be adaptive in the context of the newborn's transition to extrauterine life.