title: Sleeping position and sudden infant death syndrome in Norway 1967-91.
abstract: OBJECTIVE
  To investigate, in a population based national study, the association between sleeping position of infants and the occurrence of sudden infant death syndrome (SIDS).
  
  
  METHODS
  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 surveillance of SIDS was based on all infants born in Norway 1967-91, surviving the perinatal period. Variables studied from the questionnaire were usual sleeping position (placed), breast feeding at 3 months, and maternal smoking in pregnancy, and from the Medical Birth Registry maternal age, birth order, and birth weight.
  
  
  RESULTS
  Proportion of infants sleeping prone increased from 1970 (7.4%) to 1989 (49.1%) and dropped 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 between prone sleeping and SIDS as suggested in previous studies is supported by the present; and so far only, national study of infants' sleeping position.
authors.affiliation: Medical Birth Registry of Norway, Department of Public Health and Primary Health Care, University of Bergen.
authors.forename: L M
authors.initials: LM
authors.lastname: Irgens
authors.forename: T
authors.initials: T
authors.lastname: Markestad
authors.forename: V
authors.initials: V
authors.lastname: Baste
authors.forename: P
authors.initials: P
authors.lastname: Schreuder
authors.forename: R
authors.initials: R
authors.lastname: Skjaerven
authors.forename: N
authors.initials: N
authors.lastname: Oyen
mesh_terms: D001722:Birth Order; D001724:Birth Weight; D001942:Breast Feeding; D006801:Humans; D007224:Infant Care / Q000639:trends*; D007231:Infant, Newborn; D008423:Maternal Age; D009664:Norway / Q000453:epidemiology; D011187:Posture; D016684:Prone Position; D012189:Retrospective Studies; D012890:Sleep; D012907:Smoking / Q000639:trends; D013398:Sudden Infant Death / Q000453:epidemiology / Q000209:etiology*