Researchers from the London School of Hygiene examined the individual records of 1,472 cot death cases, also known as sudden infant death syndrome (SIDs), against 4,679 control cases.
They found that the risk of cot death among breastfed babies under three-months-old increased five-fold with bed sharing, compared to when a baby slept in a cot in the parents’ room.
The increased risk existed even if the parents did not smoke and the mother had not consumed alcohol or drugs.
The peak period for instances of cot death was between seven and ten-weeks-old. As babies got older the risk of cot death decreased.
The researchers estimate that 81 per cent of cot deaths among babies under three months with no other risk factors could be prevented if they did not sleep in the same bed as their parents.
They suggest that parents bring babies into their bed for comfort and feeding during the night, but place babies in a cot next to the bed to sleep.
According to the study, sudden infant death syndrome remains a major cause of death among babies under one-year-old in high-income countries.
It goes on to say that there is already a general consensus that sleeping with a baby increases the risk of cot death if the parents smoke or if the mother has been drinking alcohol or taking drugs. However, there are conflicting opinions as to whether bed-sharing in general represents a risk when these factors are not present.
Countries including the United States and the Netherlands advise all parents against sharing a bed with their baby for the first three months. The UK currently only advises certain groups, including parents who are smokers, not to bed share.
Professor Bob Carpenter from the London School of Hygiene & Tropical Medicine, who led the study, said, ‘Currently in the UK more than half of cot deaths occur while a baby is sleeping in the same bed as its parents. Although it is clear that smoking and drinking greatly increase the risk of cot death while bed-sharing, our study shows that there is in fact an increased risk for all babies under three months who bed share, even if their parents do not smoke or drink.
‘If parents were made aware of the risks of sleeping with their baby, and room-sharing was instead promoted in the same way that the ‘Back to Sleep’ campaign was promoted 20 years ago to advise parents to place their newborn infants to sleep on their backs, we could achieve a substantial reduction in cot death rates in the UK. Annually there are around 300 cot death cases in babies under a year old in the UK, and this advice could save the lives of up to 40 per cent of those. Health professionals need to make a definite stand against all bed-sharing, especially for babies under three months.’
The study, ‘Bed sharing when parents do not smoke: is there a risk of SIDs? An individual level analysis of five major case-control studies’, is published in the journal BMJ Open.