Infantile megaloblastosis secondary to maternal vitamin B-12 deficiency

We reviewed six cases of infantile megaloblastosis secondary to maternal vitamin B-12 deficiency, the most common cause of infantile megaloblastosis in our institution. Two patients had long-term neurological sequelae, with a further patient remaining abnormal but at short follow-up. In 50% of cases the mother was asymptomatic, with subtle or no peripheral blood abnormalities, having early pernicious anaemia. Any infant which fails to thrive, with progressive neurological deterioration and haematological cytopenias should have their vitamin B-12 and folate status rapidly assessed. This is one of the few potentially reversible causes of failure to thrive and neurological deterioration. Early diagnosis and treatment may prevent significant long-term sequelae.