Neonatal Jaundice

Background/Epidemiology

• Common (up to 60% term infants and 80% preterm infants)
  • Usually physiological- not pathological (important, however, to recognise the difference)
• Can potentially be toxic (mainly to the brain- kernicterus)
  • occurs mainly when unconjugated bilirubin crosses the BBB
  • Note that unconjugated jaundice may be physiological but conjugated jaundice (whilst not toxic) is almost always pathological

Risk factors

• The following babies require closer post-natal observation for the development of jaundice
  • Visible jaundice within 24 hours of birth
  • Pre-term infants or low-birth weight babies
  • A previous sibling who had neonatal jaundice requiring phototherapy
  • A mother who intends to breast feed exclusively

Causes

• Physiological
  • Increased breakdown of foetal Hb in combination with immature liver function
  • Presents at 2/3 days; begins to fade by week 1 and disappears usually by day 10
  • Bilirubin is rarely >200μmol/l and baby remains well
    • NB Preterm babies may have a more severe physiological jaundice which may warrant treatment (still physiological)
• Haemolytic disease of the newborn (onset <24 hours)
• Infection
  • Can be congenital e.g. toxoplasmosis; rubella; CMV; Herpes simplex; syphillis, or postnatal (post-natal infection may cause prolonged jaundice)
• Increased haemolysis e.g. due to bruising/bleeding
• Maternal autoimmune haemolytic anaemia e.g. SLE (<24 hours)
• Other syndromes e.g. Dubin-Johnson sydrome; Gilbert’s syndrome; Crigler-Najjar syndrome
• Causes of prolonged jaundice include hypothyroidism/hypopituitarism; Breast milk jaundice; GI causes e.g. biliary atresia, neonatal hepatitis; late infections (UTI)

Presentation/Investigations

• If jaundice is present, bilirubin levels should be measured
  • If suspected physiological jaundice, use transcutaneous bilirubinometer (non-invasive) to do this in the first instance
    • In early jaundice, infants <35 weeks gestation or if there is suspicion of pathological jaundice, measure serum bilirubin
    • (If transcutaneous measurement is >250μmol/l, measure serum levels)
• Infection will often present with
  • lethargy, poor feeding, jaundice may be mild but the baby will often look unwell
  • WBC count will often be raised, as will CRP; there may be metabolic acidosis
  • Important to take urine, CSF and blood cultures and start empiric antibiotic therapy
• G6PD deficiency
  • Usually rapidly progressive jaundice in an otherwise well baby
  • Low haemoglobin and high indirect bilirubin
  • More common in families of Mediterranean origin
• Galactosaemia
  • Vomiting, convulsions, irritability and lethargy, accompanied by liver enlargement and moderate jaundice
  • There may be elevated liver enzymes and presence of reducing substances in the urine
• Neonatal Hepatitis
  • Elevated direct and indirect bilirubin and liver enzymes combined with liver enlargement
  • Look for causes e.g. syphilis (respiratory infection, periostitis)
• Other investigations may be necessary to identify an underlying cause (particularly in prolonged/early jaundice) e.g. Split bilirubin; FBC/LFTs; infection screen (including urine culture); Coomb’s test; TFTs etc

Management