Young babies who share their parents' bed are significantly more likely to die from cot death, even if the parents are non-smokers, a new study indicates.

In Ireland, cot death, or sudden infant death syndrome (SIDS), is the leading cause of death in babies aged between four weeks and one year. While it is rare, and cases have fallen in recent years, four in every 10 deaths among babies here are still due to SIDS.

According to the UK scientists who carried out the research, advice on bed sharing varies depending on the country. For example, in the US and Holland, parents are advised not to share a bed with a baby who is less than three months of age. In the UK and Australia, only certain parents are told not to share a bed with young infants, such as smokers or those who have been drinking.

In Ireland, parents are advised not to share a bed with a baby of any age if they are a smoker or if they have consumed alcohol or taken drugs. However, they are also advised not to share with a baby who is less than three months old or a baby who was born prematurely or who had a low birth weight (less than 5.5lbs).

The scientists decided to investigate this further. They analysed data from five studies carried out worldwide. These included details on almost 1,500 cases of SIDS and over 4,600 controls. This marked one of the largest analysis ever carried out on this topic.

It found that babies under three months of age who shared a bed with their parents had a five-fold increased risk of dying from SIDS, even if the parents were non-smokers and the mother had not been drinking alcohol or using illicit drugs. The risk also remained if the baby was breastfed.

The scientists from the London School of Hygiene & Tropical Medicine estimated that almost 90% of SIDS cases that occurred in babies under three months of age who shared their parents' beds, could have been avoided if the child was in their own cot.

They noted that the risk of SIDS declined as the child got older, however if either parent was a smoker, or if the mother had consumed alcohol in the previous 24 hours or used illegal drugs, including cannabis, at any time since the child was born, the risk of SIDS was greatly increased if the infant was in bed with the parents.

The scientists insisted that ‘88% of the deaths that occurred while bed sharing would probably not have occurred had the baby been placed on its back in a cot by the parents' bed'.

"Even in very low-risk breastfed babies, where there were no risk factors for SIDS other than that they had slept in their parents' bed, 81% of SIDS deaths in infants under three months of age could have been prevented by not bed sharing," they emphasised.

They added that bringing a baby into a parent's bed for ‘comfort and feeding' can still be done, ‘provided the infant is returned to his or her own cot for sleep'.

Details of these findings are published in the journal, BMJ Open.

For more information on SIDS in Ireland, click here