Neonatal Jaundice

Jaundice is the yellow colouring of skin and sclera caused by the accumulation of bilirubin in the skin and mucous membranes

Aetiology

  • Neonatal jaundice occurs in 60% of term infants and 80% of preterm infants and is caused by hyperbilirubinaemia that is unconjugated (divided into physiological or pathological) or conjugated (always pathological)
  • Around 10% of term breastfed babies are jaundiced at 1 month

Pathophysiology

Unconjugated

  • Physiological - jaundice in a healthy baby, born at term, is normal and may result from increased RBC breakdown or the immature liver not being able to process high bilirubin concentrations
    • In premature babies, the process of physiological jaundice is exaggerated due to the immature liver - increases risk of complications
  • Breast milk jaundice - well baby, resolves between 1.5-4 months
  • Haemolysis
  • Infection - neonatal sepsis is a common cause of jaundice in the first 24 hours of life
  • Inherited causes
  • Intestinal obstruction

Conjugated

  • Biliary atresia
  • TPN
  • Hypothyroidism
  • Genetic conditions e.g. cystic fibrosis, trisomy 21

Prolonged jaundice

  • Jaundice is 'prolonged' when it lasts longer than would be expected in physiological jaundice - over 14 days in a term baby or 21 days in a preterm baby

Clinical presentation

Physiological Jaundice

  • Appears after 24 hours
  • Peaks:
    • Day 3–5 (term)
    • Day 5–7 (preterm)
  • Total serum bilirubin:
    • <12 mg/dL (term)
    • <15 mg/dL (preterm)
  • Resolves by 7–10 days (term)

Pathological Jaundice

  • Onset within first 24 hours
  • Rapid rise: >5 mg/dL/day
  • Very high bilirubin for age
  • Conjugated bilirubin >20% of total
  • Persists >14 days (term) or >21 days (preterm)
 

Kramer Zones Classification

Kramer Zone
Area of Jaundice Involvement
Approximate Serum Bilirubin (mg/dL)
Clinical Interpretation
Zone 1
Head and neck
5–7 mg/dL
Mild jaundice
Zone 2
Upper trunk (chest, upper abdomen)
8–10 mg/dL
Mild–moderate
Zone 3
Lower trunk and thighs
11–13 mg/dL
Moderate
Zone 4
Arms and lower legs
14–16 mg/dL
Moderate–severe
Zone 5
Palms and soles
≥17–20 mg/dL
Severe jaundice

Investigations

Bilirubin Assessment

Test
Purpose
Interpretation
Total Serum Bilirubin (TSB)
Confirm jaundice severity
>5 mg/dL = clinically visible jaundice
Direct (Conjugated) Bilirubin
Differentiate type
>1 mg/dL or >20% of TSB = pathological
Transcutaneous bilirubin (TcB)
Screening
Correlates with TSB
Clinical Scenario
Key Investigations
Jaundice <24 hours
TSB, Coombs, Hb, reticulocytes
Rapidly rising bilirubin
Repeat TSB, hemolysis workup
Prolonged jaundice
Direct bilirubin, LFTs, TSH
Pale stools + dark urine
LFTs, ultrasound, HIDA
Poor feeding + lethargy
Sepsis screen
Family history of jaundice
G6PD, RBC disorders

Management

Phototherapy

Mechanism
  • Converts unconjugated bilirubin into water-soluble isomers
Indications
Term Neonates (≥38 weeks, NO risk factors)
Age (hours)
Start Phototherapy if TSB ≥
<24 h
Pathological → urgent evaluation
24–48 h
15 mg/dL
49–72 h
18 mg/dL
>72 h
20 mg/dL
Term Neonates with Risk Factors
(*hemolysis, sepsis, asphyxia, hypoalbuminemia, G6PD deficiency)
Age (hours)
Start Phototherapy if TSB ≥
24–48 h
13 mg/dL
49–72 h
15 mg/dL
>72 h
17 mg/dL
 

Exchange Transfusion

Indications
  • Failure of intensive phototherapy
  • Signs of acute bilirubin encephalopathy
  • Very high bilirubin levels
Based on Serum Bilirubin (Term Neonates)
Age (hours)
Exchange Transfusion if TSB ≥
24–48 h
20 mg/dL
49–72 h
25 mg/dL
>72 h
25–30 mg/dL
Absolute Indications
Indication
Explanation
Acute bilirubin encephalopathy
Neurological emergency
Failure of intensive phototherapy
Persistent bilirubin rise
Severe hemolysis (Rh disease)
Ongoing bilirubin production
Rapid bilirubin rise (>1 mg/dL/hour)
Imminent kernicterus