The number of sudden infant death syndrome (SIDS) cases that occur when a parent sleeps with their infant on a sofa has increased in recent years, according to a paper published online today (Wednesday January 18, 2006) by The Lancet. The authors strongly recommend that parents avoid this sleeping environment.

The risk of SIDS is higher for male, pre-term, and low birthweight infants, and for those sleeping on their side or front. Smoking during pregnancy and exposure to secondary smoke after birth can also increase the risk of SIDS. In the 1991 UK campaign ‘Back to Sleep’, parents were told to put babies on their back to sleep; death rates from SIDS subsequently fell.

In the latest Lancet study, Professor Peter Fleming (Bristol Royal Hospital for Children, UBHT, University of Bristol) and colleagues looked at how the campaign has influenced factors that contribute to SIDS over the last 20 years. The investigators compared data from 369 consecutive unexpected infant deaths that occurred between 1984 and 2003 in Avon, UK, with data from 1,300 control babies in a UK study done between 1993 and 1996. They found that although the number of deaths in the parental bed has fallen, the number of co-sleeping deaths on a sofa has increased fourfold in recent years. They also found that for SIDS deaths the proportion of poorer families has risen from 47 per cent to 74 per cent; the prevalence of maternal smoking during pregnancy has risen from 57 per cent to 86 per cent; the proportion of pre-term infants has risen from 12 per cent to 34 per cent; and the prevalence of breastfeeding has fallen from 50 per cent to 26 per cent.

Professor Fleming said: “Although the reasons for the rise in deaths when a parent sleeps with their infant on a sofa are unclear, we strongly recommend that parents avoid this sleeping environment.” He added: “Our data clearly show that SIDS is now largely confined to deprived families, and if we exclude deaths on sofas, the numbers of babies dying while in bed with their parents has fallen by 50 per cent over the past 20 years.”

In an accompanying comment, Dr Jacobus Van Wouwe (Netherlands Organisation for Applied Scientific Research, Leiden) and Professor Remy Hirasing (VU Medical Centre, Amsterdam, Netherlands) state: “The dramatic decline in SIDS is a major public-health success.  However, the campaigns — in 1987 in the Netherlands, 1991 in the UK and 1994 in the USA — were too late for 10,000 infants in the UK and 50,000 in the rest of Europe, the USA and Australasia. The severity of the threat justified intervention without delay, and questions are raised about what caused this delay, how decisions on the campaigns were made, and why action took so long in countries with otherwise excellent health-care records. Conditions other than infectious diseases cause threats for the health of our children with pandemic features. This is still the case for secondary smoking and obesity and used to be the case for SIDS.”