What is true about bilirubin production in neonates?

The majority of bilirubin in neonates comes from the breakdown of hemoglobin, which is a natural process that occurs as red blood cells have a shorter lifespan in newborns compared to older children and adults. When red blood cells break down, hemoglobin is released and metabolized into bilirubin.

In neonates, particularly those in the first week of life, the high turnover of fetal red blood cells leads to increased production of bilirubin. This can contribute to physiological jaundice, a common condition seen in newborns. Understanding this fundamental process highlights the importance of monitoring bilirubin levels in neonates to prevent complications associated with hyperbilirubinemia, such as kernicterus.

The other options do not align with the established understanding of bilirubin physiology in neonates. For instance, conjugated bilirubin is actually water-soluble and less toxic than unconjugated bilirubin, which is fat-soluble; therefore, recognizing the properties of these forms of bilirubin is essential for effective clinical assessments.