Diagnosis of asphyxia on the sudden infant death--prone sleeping position and vomit aspiration.

An inevitable conclusion of studies in the Netherlands, Great Britain, the United States and Japan is that sudden infant death syndrome (SIDS) is intimately linked to the prone sleeping position of infants. But this cause of death cannot be explained by the conventional view of SIDS. Although asphyxia would be the most plausible explanation, the cause of death in the majority of SIDS-related deaths in Japan are ruled as SIDS, primarily because administrative autopsies in this country are delayed and the diagnosis is most often made from an external examination only. This lack of autopsy reports also hampers research in this area. Moreover, even where autopsies have been conducted, because of the lack of clear criteria for diagnosis, inconsistent rulings are rendered depending on the judgment of the presiding pathologist. Given these considerations, we undertook to examine the diagnostic criteria for death by asphyxiation among infants sleeping in the prone position, and the problems associated with such a diagnosis.