SLEEPING POSITION AND SUDDEN-INFANT-DEATH-SYNDROME IN NORWAY 1967-91

Objective-To investigate, in a population based national study, the as sociation between sleeping position of infants and the occurrence of s udden infant death syndrome (SIDS). Design-A retrospective survey and registry based ecological study. A questionnaire based surveillance of sleeping position was obtained in a random sample (n=34 799) and surv eillance of SIDS was based on all infants born in Norway 1967-91, surv iving the perinatal period. Variables studied from the questionnaire w ere usual sleeping position (placed), breast feeding at 3 months, and maternal smoking in pregnancy, and from the Medical Birth Registry mat ernal age, birth order, and birth weight. Results-Proportion of infant s sleeping prone increased from 1970 (7.4%) to 1989 (49.1%) and droppe d in 1990 (26.8%) and 1991 (28.3%). Occurrence of SIDS increased from 1970 (1.1/1000) to 1989 (2.0) before dropping in 1990 and 1991 (1.1). Implication and relevance of results-A cause effect relationship betwe en prone sleeping and SIDS as suggested in previous studies is support ed by the present, and so far only, national study of infants' sleepin g position.