The government has warned parents not to sleep in bed with their babies because it puts the child's life at risk.

New advice from the Department of Health comes after research showing that bed-sharing could be unsafe during the first eight weeks of a baby's life especially.

Findings from a study were printed in the Lancet medical journal in January, which prompted the Foundation for the Study of Infant Deaths to alert parents to the risks. Now the DoH has updated its Reduce the Risk of Cot Death leaflet, which is distributed to all maternity units in England. It advises parents that the safest place for their baby is in a cot in their room.

"While it's lovely to have your baby with you for a cuddle or a feed, it's safest to put your baby back in their cot for the first six months," it says.

Parents are also told there is an increased risk of their child dying if they are a smoker, even if they don't smoke in bed.

The baby should be laid on the back to sleep, the leaflet says, which also warns mums and dads to cut out smoking and make sure the baby does not become too hot.

Cot death or sudden infant death syndrome (Sids) results in the death of seven babies each week in the UK.

The study in The Lancet, which was part of the European Concerted Action on Sids, looked at 745 cases of cot death, revealed that 60 per cent of cases of cot death cases in Europe could be attributed to lying the baby on its front or side.

Researcher, Professor Robert Carpenter, from the London School of Hygiene and Tropical Medicine, said at the time of the study: "It is safest if a baby sleeps in a cot, in the parents' room."

He added that there was an increased risk of cot death if the mother smoked during pregnancy, and if either parent smoked near the new-born child.