AN INFANT WITH PERSISTENT JAUNDICE
History
Matthew is referred by the community midwife because he is still jaundiced at 3 weeks of age. He is seen in the paediatric clinic at 4 weeks of age. He was born at 39 weeks’ gestation by ventouse delivery and is the first child. His birth weight was 3.8 kg (75th centile). His mother had gestational diabetes controlled by diet alone. All antenatal scans and screening blood tests were normal. His mother’s blood group is O-positive. He has been well since birth.
Examination
Matthew’s weight is 4.5 kg (50th centile). On examination, his face, trunk and upper limbs are jaundiced. He is not dysmorphic, he has no bruising, and cardiovascular and respiratory examinations are normal. Abdominal examination reveals a firm liver edge 4 cm below the costal margin and a small umbilical granuloma.
INVESTIGATIONS
Normal
Urinalysis Urobilinogen Negative Positive
Bilirubin ++ Negative
Reducing substances Negative Negative
Blood
Haemoglobin 13.4 g/dL 10.7–17.1 g/dL
White cell count 8 109/L 6–21 109/L
Platelets 205 109/L 17–500 109/L
Reticulocytes 30 109/L 10–80 109/L
Blood group O Rhesus positive
Thyroid-stimulating hormone 4.6 mU/L 0.3–5.0 mU/L
Free thyroxine 13 pmol/L 9–23 pmol/L
Total bilirubin 140 mmol/L 1.7–26 mmol/L (after 1 month)
Conjugated bilirubin 110 mmol/L 15 per cent of total
Questions
• What additional questions should be asked to help determine the diagnosis?
• What is the likely cause of this infant’s prolonged jaundice?
• How would you manage this baby?
Medicine
The history should establish when jaundice first occurred, as the causes of early-onset jaundice are different from the causes of prolonged jaundice. Parents should be asked specifically about the presence of pale stools and dark urine. Pale stool indicates that bile pigments are not being excreted into the gut, and dark urine occurs with the accumulation of water-soluble conjugated bilirubin in the urine. These indicate that there is obstruction to bile flow out of the liver. The urine dipstick shows the presence of bilirubin but the absence of urobilinogen, so this child would be expected to have pale stools and dark urine.
Neonatal jaundice requiring investigation
• Early onset, 24–36 hours after birth
• Severe jaundice, at any time (definition of severe jaundice varies with age)
• Prolonged, 14 days
The causes of neonatal jaundice, including prolonged jaundice, are outlined in Case 82 (p. 243). Prolonged conjugated hyperbilirubinaemia in a baby who appears well is likely to be due to extrahepatic biliary atresia. Progressive destruction of the extrahepatic bile ducts occurs, with obstruction of bile flow and, subsequently, rapid progression of damage within the liver and cirrhosis. It is important to pick up cases of extrahepatic biliary atresia early, so that the diagnosis can be confirmed by ultrasound and liver biopsy and then surgery can be performed before irreversible damage to the liver has occurred. The outcome of the Kasai procedure (portoenterostomy) is much better for surgery performed before 60 days of age. For this reason, the case needs to be discussed promptly with the local specialist centre.
KEY POINTS
• In prolonged neonatal jaundice with a raised conjugated bilirubin fraction, the diagnosis must be extrahepatic biliary atresia until proven otherwise.
• The outcome of the Kasai procedure is much better if surgery is performed early
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