North American Registry of Midwives (NARM) Practice Exam

What is the physiological reason for jaundice in newborns?

1. Increased bilirubin production

2. Decreased life span of red blood cells

3. Liver immaturity

4. Dehydration

The correct answer is: Decreased life span of red blood cells

Jaundice in newborns primarily arises due to the immaturity of the liver, which affects its ability to process bilirubin efficiently. In newborns, particularly those who are premature or full-term, the liver may not yet be fully developed, leading to a buildup of unconjugated bilirubin in the bloodstream. This condition is known as neonatal hyperbilirubinemia. While it is true that the lifespan of red blood cells is shorter in newborns and can contribute to increased bilirubin due to the breakdown of hemoglobin, the dominant factor causing jaundice is more aligned with the liver's inability to conjugate and excrete bilirubin efficiently. Hence, while decreased red blood cell lifespan does play a role in bilirubin levels, it is insufficient to fully account for the prevalence and physiological basis of jaundice in this population. In summary, the physiological reason for jaundice in newborns is fundamentally linked to liver immaturity, which hampers the processing of bilirubin and therefore results in its accumulation in the body.