Neonatal Jaundice

Neonatal jaundice is defined as an increase in bilirubin concentration greater than 5 mg/dL. This condition occurs due to either an increased rate of hemolysis (breakdown of red blood cells) or decreased bilirubin conjugation and excretion by the liver.

Physiological vs. Pathological Jaundice

Physiological Jaundice

Physiological jaundice is considered normal and has the following characteristics:

• Timing: Develops after 24 hours of life
• Rate of increase: Less than 0.5 mg/dL daily
• Peak levels: Maximum of 14-15 mg/dL
• Bilirubin type: Predominantly indirect (unconjugated) bilirubin

Pathological Jaundice

In contrast, pathological jaundice raises red flags and requires immediate attention. Key warning signs include:

• Early onset: Jaundice appearing within the first 24 hours of life
• Rapid rise: Bilirubin increasing by more than 0.5 mg/dL per hour
• Bilirubin type: Predominance of direct (conjugated) bilirubin
• Duration: Persistence beyond two weeks of age

The Importance of Monitoring: Preventing Kernicterus

Neonatal hyperbilirubinemia requires close monitoring to prevent kernicterus, a serious neurological complication. Kernicterus occurs when bilirubin deposits in critical brain regions, including the basal ganglia, pons, and cerebellum. This presents as:

• Choreoathetosis (involuntary writhing movements)
• Sensorineural hearing loss
• Gaze abnormalities (esp. upward gaze palsy)
• Dental enamel hypoplasia - This can result in thinner or weaker enamel, making teeth more vulnerable to decay and other issues
• Intellectual disability

This potentially devastating condition typically develops when bilirubin concentrations reach 25-35 mg/dL, making early detection and intervention essential for protecting newborn brain development. Treatment to prevent severe unconjugated hyperbilirubinemia and subsequent kernicterus is phototherapy or exchange transfusion.

Learn more about Pediatric hyperbilirubinemia here