A STUDY by North-East cot death researchers has found important differences in the way breast-feeding and bottle-feeding mothers sleep with their babies.

They hope their findings could lead to new guidelines for bed-sharing and a reduction in cot deaths.

Researchers at Durham University filmed 40 couples and their babies at their Stockton sleep laboratory, using infra-red lights.

Set up as an ordinary bedroom, the laboratory tries to recreate a home-like setting.

They found that breast-feeding mothers seem instinctively to adopt a safer sleeping position compared with those who bottle feed.

While breast-feeding mothers seem automatically to adopt a safe sleeping position, curled around their baby with its head at breast level, mothers who bottle-feed tend to put the baby's head on the pillow as if they were sleeping alongside another adult.

Experts fear that this position could lead to babies being smothered.

Anthropologist Dr Helen Ball, who heads the Durham sleep unit, said: "Many formula-feeding mothers put their babies' heads on the pillows, like an adult.

"This is less safe because the baby could get smothered. We concluded that mums who are not breast-feeding need guidance on what safe bed-sharing looks like."

Dr Ball presented her findings to the Foundation for the Study of Infant Deaths in London.

Bed-sharing continues to cause controversy among medical and child-care experts.

Some believe that bed-sharing helps women to breast-feed during the night and may help to prevent sudden infant death syndrome, or cot death.

But other experts claim that bed-sharing increases the risk that babies will become poor sleepers and that the practice can increase the risk of cot death.

Dr Ball said their research set out to see if there was a safe bed-sharing position for mothers and their babies.

"What emerged was a picture of the mum and baby sleeping orientated towards each other with the baby's face level with its mum's breast," said Dr Ball.

The team also found that babies who shared their parents' bed were only 0.1C warmer than those who slept in cots, scotching rumours that bed-sharing can lead to babies over-heating.