[Significance of sleeping position on the occurrence of sudden, unexplained infant death. An epidemiological review]

The cause of the sudden infant death syndrome (SIDS) is, according to the definition, unknown. Epidemiological research during recent years has identified a series of probable risk factors. One of these is the use of prone position as sleeping position. In the Western European countries, Australia and New Zealand, a total of 14 case-control studies illustrate a possible connection between the prone position and SIDS. Eleven of the studies revealed a significantly increased relative risk (RR) of between 1.4 and 12.5 for SIDS when using the prone position, while the three remaining studies did not demonstrate increased RR. A meta-analysis of the results of the 14 case-control studies showed an RR of 2.4 for SIDS in the prone position as compared with other sleeping positions. In a single prospective cohort study from Australia, an RR of 3.1 was found for SIDS in the prone position. Interventions in which parents are advised not to place the infants in the prone position during sleep appear to have resulted in considerable reduction in the number of cases of SIDS according to preliminary reports from Great Britain, the Netherlands, Norway and New Zealand. A series of methodological problems can be demonstrated in the published results of these studies, including limited size of study populations, inadequate matching of control groups and absent confounder control. Nevertheless, the total epidemiological evidence, also where Denmark is concerned, speaks in favour of altered recommendations for sleeping positions of infants, particularly because there is no documentation to suggest that the prone position offers any advantages to health.(ABSTRACT TRUNCATED AT 250 WORDS)