New knowledge, new insights, and new recommendations.

T he fall in numbers of unexpected infant deaths that followed ‘‘Back to Sleep’’ intervention campaigns in many countries in the early 1990s has been one of the striking achievements of applied epidemiology in the field of child health in modern western society. 2 The possibility that other modifiable risk factors might be amenable to similar interventions in this mysterious group of conditions has led to multiple studies of the epidemiology of the residual unexpected infant deaths. Having been central participants in the implementation of the ‘‘Back to Sleep’’ campaigns in many countries, the media remain acutely alert to the possibility of any new or significant developments in this field. Thus any public pronouncements by professional organisations must be made in the knowledge that they will attract intense media attention. The recent Policy Statement by the American Academy of Pediatrics (AAP) on the changing concept of sudden infant death syndrome (SIDS) and approaches to its prevention aroused an unusual level of criticism and hostility both within and beyond that organisation. Despite the careful presentation of the evidence on which their recommendations were based, and the largely uncontroversial nature of most of the recommendations, the responses—by media and professionals alike—to the report of the AAP Task Force on SIDS have concentrated on the two issues of bedsharing and pacifier (dummy) use, and largely ignored the other nine recommendations (box 1)— most of which are based on stronger and less controversial data. The scientific rigour with which data is gathered is not easily applied to the dissemination of the results and formulating advice can be a subjective exercise of weighing up the available evidence and constrained by attempts to simplify the message. The AAP’s recommendations to advise against bedsharing and promote dummy use needs to be questioned, not for the carefully weighed evidence presented but rather the gaps in our knowledge of infant care practices and their consequences that still remain. An infant sharing a bed with an adult (usually the mother) who smokes or has taken alcohol or other consciousness affecting medications has been clearly shown in multiple studies to be at substantially increased risk of unexpected death, over and above the risk associated with maternal smoking. Most studies have shown no increased risk from infants bedsharing with nonsmoking mothers, though the large multicentre European study showed a small risk, and a Scottish study showed a larger risk, particularly for younger infants, though no account was taken of parental alcohol intake. Sleeping with an infant on a sofa is also associated with a particularly high risk, compounded by the circumstances in which sofa sharing occurs—e.g. changes to normal sleep routines, or social deprivation. Clearly there are inappropriate circumstances or environments in which co-sleeping occurs, with increased vulnerability of some infants, and these deserve further investigation. Over the last three years we have been investigating all unexpected infant deaths in the southwest of England (population 5 million), approximately half of whom were co-sleeping with a parent. The vast majority (.90%) of these co-sleeping deaths occurred in an unsafe co-sleeping environment as defined by current UK guidelines (parents smoke, have recently consumed alcohol or taken drugs, slept on a sofa, or a combination of these factors). After thorough death scene and postmortem investigations we have no evidence that the few SIDS deaths that occurred in a relatively safe co-sleeping environment are more than would have happened if the infants had slept alone in cots. Nationally up to 100 000 non-smoking mothers bring their infant into the parental bed to sleep each night. 15 Changing current guidelines to advise against co-sleeping for this particular group of mothers would seemingly have little if any effect on the SIDS rates but could deny these mothers and infants any potential advantages in co-sleeping, including accessibility to the breast. The relative proportion of unexpected infant deaths in which the infant was sharing a sleep surface with an adult has undoubtedly increased in several countries over the past few years, and been widely reported among recent case-control studies of SIDS infants. However, there is no evidence that the number of bedsharing deaths has risen— and some evidence that the absolute number of such deaths has fallen in the UK, at a time when the practice of bedsharing has increased. 4 16 The