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Vitamin K deficiency bleeding — RACP Paediatrics MCQ

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HardNeonatologyVitamin K deficiency bleedingRACP Paediatrics

A 4-week-old exclusively breastfed infant presents with lethargy and a bulging fontanelle. CT brain shows intracranial haemorrhage. The parents declined the birth injection and there is no trauma history. Coagulation studies show markedly prolonged PT with normal platelet count. What is the most likely cause?

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Correct answer: B — Vitamin K deficiency bleeding

Late vitamin K deficiency bleeding can cause intracranial haemorrhage in breastfed infants who did not receive prophylaxis, with a prolonged PT and normal platelet count. Haemophilia more typically prolongs APTT rather than PT. The prevention message is that intramuscular vitamin K at birth is highly protective.

Reference: Australian neonatal vitamin K prophylaxis guidance; RACP Knowledge Guides