NEONATAL SOCIETY ABSTRACTS
Vitamin K deficiency bleeding in New Zealand after the vitamin K - cancer controversy: an 11 year surveillance study
Presented at the Neonatal Society 2009 Summer Meeting (programme).
Darlow BA, on behalf of the New Zealand Paediatric Surveillance Unit
University of Otago, Christchurch School of Medicine, PO Box 4345, Christchurch, New Zealand.
Background: In 1992, after a UK study suggested an association between intramuscular (i.m.) vitamin K and an increased incidence of childhood cancer, an expert New Zealand committee recommended off-label oral vitamin K be given except in high risk circumstances. Further changes in recommendations were made in 1995 and 2001.
Aims: To undertake and report monitoring of vitamin K deficiency bleeding (VKDB) in New Zealand from 1998, through the transition to a new single vitamin K preparation licensed for oral or i.m. use in 2001, to 2008.
Methods: Reporting of VKDB was undertaken using the report card system of the New Zealand Paediatric Surveillance Unit (NZPSU), from 1998 to 2008. VKDB was defined as Early (first day of life), Classic (days 2 to 7) or Late-onset (day 8 to 6 months) type. The study was approved by the Otago Ethics Committee as part of the NZPSU’s rare disease surveillance process.
Results: The response rate of surveillance cards averaged 94.5% per annum. There were 35 notifications of VKDB with one questionnaire not returned (97% return rate) and 25 valid cases. The overall incidence of definite Classic VKDB (8 cases) was 1.25 per 100,000 births; none received vitamin K prophylaxis, 7 were fully breast-fed and one not fed, and all fully recovered. The overall incidence of definite Late-onset VKDB (9 cases) was 1.4 per 100,000 births; 8 received no vitamin K prophylaxis and 8 were fully breast fed. Two-thirds had liver disease, 4 suffered an intracranial haemorrhage and one died. Classic cases occurred throughout the study period but Late-onset cases were rare after 2002. Confirmation of VKDB was often hampered by less than ideal laboratory investigations. Indirect evidence suggests 95% of New Zealand infants receive i.m. vitamin K at birth.
Conclusions: In New Zealand, VKDB is virtually confined to fully breast-fed infants not given vitamin K at birth. Late-onset cases were frequently associated with liver disease.