Changes in the epidemiological pattern of sudden infant death syndrome in southeast Norway, 1984–1998: implications for future prevention and research

Abstract

Aim-To look for changes in risk factors for sudden infant death syndrome (SIDS) after decrease and stabilisation of the SIDS rate. Methods-Questionnaires were distributed to parents of 174 SIDS infants, dying between 1984 and 1998, and 375 age and sex matched controls in southeast Norway. Results-The proportion of infants sleeping prone has decreased, along with the decrease in SIDS rate for the region during the periods studied, but over half of the SIDS victims are still found in the prone position. As the number of SIDS cases has decreased, additional risk factors have become more significant. Thus, after 1993, a significantly increased risk of SIDS is seen when the mother smokes during pregnancy. After 1993, young maternal age carries an increased risk. Maternal smoking and young maternal age are associated with each other. For SIDS victims, an increase in the number of infants found dead while co-sleeping is seen, and the age peak between 2 and 4 months and the winter peak have become less pronounced. Conclusion-Changes in risk factor profile following the decrease in SIDS rate in the early 1990s, as well as consistency of other factors, provides further clues to SIDS prevention and to the direction of further studies of death mechanisms. (Arch Dis Child 2001;85:108-115)

Sudden infant death syndrome

“…This characteristic age distribution has decreased in some countries as the SIDS incidence has declined, with occurrence of deaths at earlier ages and flattening of the peak incidence. 16,17 Similarly, the commonly found winter seasonal predominance of SIDS has declined or disappeared in some countries as the prevalence of infants sleeping in the prone position has decreased, which supports prior findings of an interaction between sleeping position and factors more common during colder months (e.g., overheating and infection). 18,19 Infant boys are 30%-50% more likely than girls to be affected.…”

Racial Disparity and Modifiable Risk Factors Among Infants Dying Suddenly and Unexpectedly

“…There, use of the prone position has de- clined rapidly in recent years and subsequently, the ratio of infants found nonprone to those found prone has increased. 11 One possible explanation for the similar overall ratios of infants found prone to nonprone in the AA and non-AA groups may be attributable to the increased deaths occurring during bedsharing in AA infants. This follows from the observation that bedsharing infants were more likely to be found nonprone than prone as compared with infants who did not bedshare.…”

Infant Sleep Location: Associated Maternal and Infant Characteristics with Sudden Infant Death Syndrome Prevention Recommendations

“…(4,5) As the rate of prone positioning has declined, other previously unrecognized risk factors for sudden unexplained infant death have emerged in recent epidemiologic studies. Despite the fact that bedsharing between an infant and adult facilitates breastfeeding and enhances parent-infant interactions, (6,7) this sleeping arrangement has been identified in epidemiologic studies as being hazardous in certain situations, particularly when one or both parents are smokers, (8)(9)(10)(11)(12) on excessively soft surfaces, such as waterbeds, sofas, and armchairs, (9,10,(13)(14)(15) or when the infant is less than 2-3 months of age. (9,12,(14)(15)(16)(17) In addition, there is an increased risk for sudden unexpected infant death when there are multiple bedsharers (13) and when bedsharing occurs for the entire night.…”