Babies sleeping with parents: case-control study of factors influencing the risk of the sudden infant death syndrome

Objective To investigate the risks of the sudden infant death syndrome and factors that may contribute to unsafe sleeping environments. Design Three year, population based case-control study. Parental interviews were conducted for each sudden infant death and for four controls matched for age, locality, and time of sleep. Setting Fire regions in England with a total population of over 17 million people. Subjects 325 babies who died and 1300 control infants. Results In die multivariate analysis infants who shared their parents' bed and were then put back in their own cot had no increased risk (odds ratio 0.67; 95% confidence interval 0.22 to 2.00). There was an increased risk for infants who shared the bed for the whole sleep or were taken to and found in the parental bed (9.78; 4.02 to 23.83), infants who slept in a separate room from their parents (10.49; 4.26 to 25.81), and infants who shared a sofa (48.99; 5.04 to 475.60). The risk associated with being found in the parental bed was not significant for older infants (> 14 weeks) or for infants of parents who did not smoke and became non-significant after adjustment for recent maternal alcohol consumption(> 2 units), use of duvets ( > 4 togs), parental tiredness (infant slept less than or equal to 4 hours for longest sleep in previous 24 hours), and overcrowded housing conditions (> 2 people per room of the house). Conclusions There are certain circumstances when bed sharing should be avoided, particularly for infants under four months old. Parents sleeping on a sofa Midi infants should always be avoided. There is no evidence that bed sharing is hazardous for infants of parents who do not smoke.