A coroner has warned that more than 300 babies may be dying each year in England and Wales after sharing a bed or sofa with their parents.
Yorkshire-based Roger Whittaker says he has seen 12 accidental smothering cases in the past two years and believes this must be happening across the country.
The Department of Health advises the safest way for babies to sleep is in a cot in the same room as the mother.
Midwives tell mothers of both the advantages and risks of bed-sharing.
But Mr Whittaker, who covers Bradford Calderdale and Kirklees, is calling on midwives to change their stance. He estimates that more than 300 babies a year may be dying through smothering.
Melanie Every, a regional manager for the Royal College of Midwives, told BBC Radio Five Live bed-sharing had some benefits for breast-feeding mothers and their children, and trying to prevent it could be counter-productive.
"We know that there are many, many cultures and many, many women who will continue to share beds with their babies, even when they are advised not to do it," she said.
"Now, knowing that, it's important to give them advice on the safest possible way of doing it, rather than just saying, don't do it."
Mr Whittaker reports that his fellow coroners in West Yorkshire and North Lincolnshire have seen similar numbers of deaths, prompting his estimates.
Mr Whittaker said: "That's far too many. One is far too many in what I consider to be a totally avoidable situation.
"These children had nothing else wrong with them. They had everything before them and should have fulfilled their potential."
Last year the Department of Health altered one of its leaflets to highlight the risks of bed-sharing.
The leaflet, published in November 2005, states: "The safest place for your baby to sleep is in a cot in your room for the first six months.
"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 before you go to sleep."
It also lists other potential risks for triggering cot deaths, including smoking or taking alcohol or drugs while sharing a bed with a baby.
It goes on: "There is also a risk that you might roll over in your sleep and suffocate your baby, or that your baby could get caught between the wall and the bed, or could roll out of an adult bed and be injured. Never sleep with a baby on a sofa or armchair."
Mr Whittaker believes midwives need to change their guidance and make it clear that parents should not share a bed with babies.