An analysis of trends in the incidence of sudden infant death in The Netherlands 1969-89.

There is considerable interest in the relationship between sleeping position and the occurrence of sudden infant death syndrome (SIDS). As changes have been reported in The Netherlands in the position infants have been placed to sleep, the national Dutch sudden infant death rates were analyzed over the time that such changes have taken place. The overall post-perinatal death rate (1 week less than 1 year) was around 4-4.5 per 1000 live births from 1969 until 1985. From 1985 until 1989 the rate fell from 4.1 to 2.9 per 1000 live births. During the same period the cot death/SIDS rate rose from 0.44 per 1000 in 1969 to between 1.08 and 1.31 per 1000 in 1977-87, and subsequently fell to 0.7 per 1000 in 1989. These trends coincided with changes in prone sleeping position demonstrated in national surveys. The problems of interpreting such national data, with only 50-60% of infant deaths being autopsied and with the possibilities of misclassification over time, are fully discussed. The data are supportive of the relationship between prone sleeping position and cot death.