Despite the fact that the number of cases of babies dying from Sudden Infant Death Syndrome (SIDS) has fallen dramatically over the last two decades, it seems that the number of deaths in children while sleeping with a parent on a sofa have risen 400 percent.
Researchers at the the Royal Hospital for Children in Bristol, England, say campaigns to inform parents about SIDS, or cot deaths, have had an impact, but parents need to be aware of the danger of falling asleep with a baby on a sofa.
Professor Peter Fleming, who headed the research team, says the numbers of deaths of babies in bed with their mothers has gone down by 50 percent but the number of deaths on a sofa with a parent has gone up by 400 percent.
Fleming says some of the mothers had simply not understood just how hazardous sleeping on a sofa with their baby was.
At present the reasons why it is so dangerous are unclear.
Although the findings are based on British data, according to Fleming the results are probably representative of most developed countries.
To date SIDS, which is when babies die inexplicably in their sleep, remains the leading cause of death in children under a year old.
Its cause is unknown but lying the infant face-down, parental smoking and old mattresses which may harbour bacteria have been suggested as possible causes.
Fleming and his team studied data on 369 SIDS deaths between 1984 and 2003 in southern England and compared them with information on 1,300 other babies.
They discovered, in addition to the rise in SIDS cases on sofas, a huge increase in the proportion of cot deaths in deprived families.
They found that though the number of SIDS deaths in poor families had dropped during the course of the study, it had not fallen as quickly as in other groups.
According to Fleming, it seems that women in poorer socio-economic groups were more likely to smoke, and eighty-six percent of babies in the study who died in the last 5 years had mothers who smoked.
Fleming says that smoking contributes both directly and by virtue of its association with poverty.
He believes that the prevention message to reduce cot deaths should be targeted at the most economically deprived groups.
Fleming and the team say that of the deaths that are still happening, at least three-quarters are potentially preventable with present day knowledge.
The study findings are published in The Lancet medical journal.