Sharing a bed with parents increases the risk of cot death by five times, a study published in BMJ Open suggests.
Research from the London School of Hygiene and Tropical Medicine found an increased rate of sudden infant death syndrome (SIDS) even when parents are non-smokers and the mother has not been drinking alcohol or using illegal drugs.
Close to 90% of all SIDS deaths while bed sharing could have been avoided if the baby had slept in a cot instead of with the parents, the authors analysis showed.
Yet if either parent was a smoker or the mother had drunk alcohol or used illegal drugs at any time since the child was born, the risk was greatly increased.
Professor Bob Carpenter, who led what is the largest individual study on SIDS to date said: “We do not suggest that babies should not be brought into the parent’s bed for comfort and feeding.
“This has been investigated in previous studies and has not been found to be a risk factor, provided the infant is returned to his or her own cot for sleep.”
National guidelines 'needed'
UK guidelines suggest parents who smoke and those who have been using alcohol or drugs not to share a bed with an infant.
However, other countries such as the Netherlands and the USA advise parents not to sleep in the same bed as infants less than three months old.
The study shows one or both parents of 22.2% of the infants who had died from SIDS had been sleeping with their child at the time of death, while 9.6% of the parents in the control group had awoken the morning of the interview in the same bed as their child.
The study combined individual data from five published data sets from the UK, Europe and Australasia. It includes data on 1472 SIDS cases and 4679 controls.
Over the past 10 years, there has been a marked increase in bed sharing and the authors now estimate that around 50% of SIDS cases occur while bed sharing, more than double the figure found in the study.
The researchers have called for recommendations that “that take a more definitive stance against bed sharing for babies under 3 months”.