Shaken baby syndrome in New Zealand, 2000-2002

Aim: To describe the epidemiology of subdural haemorrhage (SDH) in New Zealand infants. Methods: Prospective enrolment of all cases of infantile SDH from 2000 to 2002. Retrospective analysis of national discharge and death data for the same period. Results: Seventy-seven cases of infantile SDH were identified prospectively, and a further 49 cases retrospectively. Of these 126 cases, 92 resulted from non-birth-related trauma. Forty-eight of these were attributed to abuse and 28 to accidental injury. Sixteen cases were undetermined. The 'minimum' annual incidence of inflicted infantile SDH in New Zealand is 14.7 per 100 000 (95% confidence interval(CI) 10.8-19.4), and the 'maximum' 19.6 per 100 000 (95% CI 15.1-25.0). Among Maori, the 'minimum' is 32.5 per 100 000 (95% CI 21.4-47.3), and the 'maximum' 38.5 per 100 000 (95% CI 26.3-54.4). Conclusions: The epidemiology of infantile subdural haemorrhage in New Zealand is similar to that described elsewhere. Non-accidental head injury is a significant child health issue in New Zealand, and the incidence is particularly high among Maori.