Neonatal vitamin K prophylaxis: the Gordian knot still awaits untying

A small risk of leukaemia still has not been excluded, but safe and effective prophylaxis seems possible

Since 1990 the issue has remained unresolved of whether prophylactic vitamin K, given to newborn infants to prevent bleeding, causes childhood cancer. Four more studies appear in this week's issue. Do they finally conclude the vitamin K and cancer story?

When I went into paediatrics some 20 years ago vitamin K prophylaxis was not an issue. In Germany at least almost all newborn infants who required medical care and many who had had instrumental deliveries were given 1 mg of vitamin K intramuscularly, whereas the practice in healthy infants varied. Altogether only about half of all live births received intramuscular vitamin K, but vitamin K deficiency bleeding did not seem to be major problem until an apparently new condition-late vitamin K deficiency bleeding-emerged in Europe in the early 1980s.1

About half the cases with late vitamin K deficiency bleeding presented with intracranial haemorrhage. The condition was confined mainly to breast fed infants, had a peak incidence at weeks 2-6, and was often caused by underlying cholestatic disease, diagnosed only after the bleeding occurred. In the absence of prophylaxis the incidence of late vitamin K deficiency bleeding in Europe was estimated to be 40-100 per million live births.2 Although the annual number of cases was low, the condition became a major issue in paediatrics, partly because of the severity of the bleeding-which led to death or severe handicap in about a third of cases-but mainly because the bleeding was thought to be preventable by …