Pediatrics - Neonatal Jaundice: By Kristen Hallett M.D.

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Pediatrics - Neonatal Jaundice
Whiteboard Animation Transcript
with Kristen Hallett, MD
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Jaundice, a yellowing of the skin and conjunctiva, is common in newborns, and usually is benign. However, some instances of neonatal jaundice are early signs of a serious underlying disorder. It is critical to differentiate benign physiological jaundice from that of a pathological process.
Jaundice is caused by an elevated level of unconjugated bilirubin in the blood. When red blood cells are broken down, they release unconjugated bilirubin which binds to albumin and travels to the liver to become water-soluble through a process called conjugation. Conjugated bilirubin is subsequently excreted into the GI tract through the bile duct and leaves the body through newborn stool.
Problems in any of these steps can cause hyperbilirubinemia. This is often normal in a newborn because newborns have:
Relatively high number of RBCs compared to adults
Shorter RBC lifespan
Slower liver conjugation
Increased reabsorption of conjugated bilirubin from the GI tract
Free unconjugated bilirubin is lipid-soluble and therefore can cross the blood-brain barrier and deposit in the brain. In pathologic hyperbilirubinemia, enough free unconjugated bilirubin accumulates in the brain to cause a condition called kernicterus. This may result in hearing loss, irreversible brain damage and/or death.
The distinction between normal and abnormal levels of bilirubin depends on the baby’s gestational age, hours of life, and risk factors for RBC breakdown and/or acidosis.
If a newborn develops jaundice in the first 24 hours of life, or is determined to have abnormally high levels of bilirubin, you should immediately begin a work-up for possible sepsis and blood group incompatibility. These would both cause an increased RBC breakdown and therefore increased levels of bilirubin.
Examples of other causes include those that would decrease the liver’s ability to conjugate bilirubin, such as G6PD deficiency or hypoxic liver injury, and those that would decrease excretion of conjugated bilirubin, such as dehydration from poor feeding and intestinal pathologies or obstructions.
Treatment for hyperbilirubinemia is phototherapy, which uses light to conjugate the free bilirubin and increase its secretion.
If the hyperbilirubinemia is too severe, exchange transfusion may be necessary.