4 January 2012

Dear Editor,

We read with interest the paper by Weber et al.1 and suggest that the findings need to be put into context, both in terms of what happens in the surviving infant population and the specific circumstances surrounding bed-sharing deaths. The limitations of the study design and inconsistency in the details available makes such contextual interpretation difficult. Recently, we conducted a population-based case–control study in the south-west of England2 that can answer both these questions. We too found that over 50% of the sudden infant death syndrome (SIDS) deaths occurred in co-sleeping situations but also a similar situation for 21% of our age-matched controls, suggesting that we would expect a fifth of the SIDS deaths to occur whilst co-sleeping, and this fact may have nothing to do with the causal mechanism of death. Much of the excess risk associated with co-sleeping seems to be associated with recent parental alcohol consumption, illegal drugs and/or using a sofa to co-sleep. The multivariable interaction between co-sleeping and the consumption of drugs and/or alcohol was significant, and the high number of unexplained co-sleeping deaths on a sofa found in Weber's study and ours confirms observations3 that the only sleeping environment in the UK in which SIDS deaths are increasing is those found co-sleeping on a sofa. Removing these hazardous conditions showed the proportion of co-sleepers was similar (18% vs. 16% controls) and in the opposite direction (6% vs. 10%) if we further removed parents who regularly smoked. Thus, the message we need to get across is not that all parents should avoid co-sleeping, but that all parents should avoid drinking alcohol, taking drugs or smoking if they want to sleep with their baby, and that co-sleeping on a sofa is a far more dangerous practice than using the parental bed.

We welcome the recent press announcement by the FSID to actively monitor infant death data and emphasise the importance of including details on recent drug and alcohol consumption, parental smoking and use of sofas. Our study2 showed that for infants sleeping in a cot, the most common sleeping position both for healthy infants and those who died was supine, which has repeatedly been shown to be the safest sleeping position. In the absence of control data, this finding could have led to entirely incorrect conclusions being drawn. Thus national monitoring should include age-matched data from the surviving infant population to avoid the possibility of misleading anecdotal observations.


  1. Top of page
  2. References
  • 1
    Weber MA, Risdon RA, Ashworth MT, Malone M, Sebire NJ. Autopsy findings of co-sleeping-associated sudden unexpected deaths in infancy: relationship between pathological features and asphyxial mode of death. J. Paediatr. Child Health 2012; 48: 33541.
  • 2
    Blair PS, Sidebotham P, Evason-Coombe C, Edmonds M, Heckstall-Smith EM, Fleming P. Hazardous cosleeping environments and risk factors amenable to change: case-control study of SIDS in south west England. BMJ 2009; 339: b3666.
  • 3
    Blair PS, Sidebotham P, Berry PJ, Evans M, Fleming PJ. Major changes in the epidemiology of Sudden Infant Death Syndrome: a 20 year population based study of all unexpected deaths in infancy. Lancet 2006; 367: 3149.