Sudden infant death syndrome during low incidence in Sweden 1997-2005

Background: Following the change from prone to supine in preferred sleeping position, the incidence of Sudden Infant Death Syndrome (SIDS) in Sweden fell from 1.1 per 1000 live births in 1992 to 0.41 in 1995. After a further small decline, we have been experiencing a plateau at around 0.25 since 2000. Aim: To identify the changes that have occurred in the epidemiology of SIDS since the end of the Nordic Epidemiological SIDS Study in 1995. Methods: Data from the Medical Birth Register of Sweden, covering the years 1995–2005, were used. Sleeping position is not included in the register. Results: The incidence of SIDS has remained low in Sweden. Independent risk factors were smoking during early pregnancy, parents not living together, low maternal age, high parity and short gestational age. The odds ratio for smoking has continued to increase and the median age of death has continued to decrease since the previous study. We found no signs of seasonality in the current material. Conclusions: Age at death continued to decrease. The high incidence during weekends persisted. Seasonality was not significant. There was no evidence of a changing effect from risk factors in the studied period.