The prone sleeping position and SIDS. Historical aspects and possible pathomechanisms.

The incidence of SIDS decreased during the previous 25 years significantly. This is mainly due to epidemiological research identifying important risk factors such as prone sleeping position and subsequent campaigns to reduce this risk factor.Originally, the prone sleeping position for babies had been strongly recommended in the sixties and seventies despite previous publications pointed to the associated risk. Worldwide, many infants died of SIDS whose deaths could have been avoided. Today, the recommendation that infants should sleep in supine position has been scientifically verified. In supine sleeping position, pathophysiological mechanisms can be avoided which may lead to hypoxia and death in prone position. Such mechanisms could be occlusion of airways (in particularly associated with face-down position), elevated diaphragm, positional cerebral hypoxia caused by constriction of arteries, rebreathing CO2, and overheating.Irrespective of the specific pathomechanism leading to death in individual cases, it has been established that the prone position is the most important risk factor for SIDS and therefore should be incorporated in the definition of the term SIDS.