[Sudden infant death syndrome: respiratory causes].

Sudden infant death syndrome (SIDS) claims one in five hundred babies between 1 and 12 months of life. Since no cause of death is found at autopsy, SIDS has been and often remains a complete enigma for pediatricians, physiologists and forensic pathologists. However, there is growing evidence from careful epidemiologic, pathologic and physiologic studies that subtle changes occur in those babies for a variable period of time before death. Some of these data are reviewed and interpreted in the light of the sleep apnea-hypoventilation inducing chronic hypoxemia hypothesis. It appears that no single factor is characteristic of, or responsible for, SIDS; rather, a combination of different adverse circumstances occurring during a period of increased vulnerability may cause the fatal outcome in some infants. Some preventive aspects of SIDS in low birth weight babies, siblings of SIDS victims and near-miss SIDS are discussed.