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

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