Background: Sudden infant death syndrome (SIDS) may have several etiologies, all of which must be identified in order to recognize those infants believed to be at risk. One of the best ways to do this is by prospective studies on a large population of infants who died of SIDS.
Methods: A total of 171 infants who died from SIDS between January 1, 1986 and June 30, 1991, were studied. 154 infants were completely investigated, including a post mortem examination. They were assigned to one of 4 groups, according to whether death was due to diseases of poor prognosis (group A), diseases that are occasionally fatal but potentially treatable (group B), minor diseases not normally fatal (group C), or was essentially unexplained (group D).
Results: The classical risk factors for SIDS were found in this population: incidence peaked in males (sex-ratio 1.5), during the cold seasons (62%), between 1 and 6 months of age (94%), mainly between 1 and 4 months of age (84%). Symptoms were definitely present during the 2 days before death in 50%. 20% of cases had clinical histories of congenital disease, complicated or recurrent postnatal disease, or fulminant recent disease. Group A included 107 infants (69% of the 154 completely investigated patients). Premature birth (17.5%) and low birth weight for gestational age (10.5%) were more frequent in our series than in the normal population.
Conclusion: The cause of death was identified in about 75% of cases. This possibility improves management of further siblings of SIDS victims even though the variety of risk factors makes prevention of SIDS difficult.