As many as half of all babies in England have slept in the same bed as their parents by the time they are six months old. In some instances, including cases where parents have fallen asleep on a sofa, it has resulted in tragedy.
The Victoria Derbyshire programme has discovered that many parents who co-sleep are so fearful about being judged they are not telling health visitors about it.
Experts say they are concerned that as a result guidance on how to minimise the risks of co-sleeping is not being passed on.
Dawn Barclay, from Forfar, recalls the first few weeks of her baby Fern's life.
It was 2014, and Dawn says lying next to Fern was the only way her daughter would sleep.
"I'd do it the safest way possible. I would remove the pillows, she would be on her back, with my hand on her chest.
"No-one else - husband or other child - in the bed with us. To have her close was just the most natural thing in the world."
'Lying on the couch'
Tragically, Dawn took a nap one morning with her eight-week-old daughter on the sofa. She woke to find Fern had stopped breathing.
"She woke up and had a feed, and we both had fallen back asleep, but we were lying on the couch."
Dawn cried for help as soon as she knew something was wrong.
"The fear that I had done something to her was one of the first things to go through my mind, I didn't understand what else was going on apart from the fact that I thought I'd killed my baby.
"I remember lifting her up and just running through to Andy, and screaming that she was gone."
Dawn said her husband started doing CPR.
"I thought he'd managed to bring her back. He managed to get the colour to come back in her cheeks," she says.
But Andy was unable to resuscitate Fern.
"I just remember falling to the ground and just screaming," Dawn says.
Nine months later, following a coroner's report, it was discovered that Fern had suffered damage on her brain from birth that might have stopped her breathing.
Her death certificate was changed from inconclusive to "sudden unexpected death in infancy associated with co-sleeping" - a ruling Dawn still believes is unfair.
What are the dangers?
Co-sleeping with babies is a sensitive subject, with many parents feeling it is natural, or that the only way to get their children to sleep is by lying in the same bed with them.
However, the official advice is that there is an increased risk of infant death while sharing a bed.
In the UK, just under 300 babies die of sudden infant death syndrome (Sids) in their sleep every year, according to the NHS.
Potential dangers include babies falling out of bed, getting overheated under a duvet, or being suffocated by their parents, pillows or loose bedding.
The Department of Health recommends the safest place for a baby to sleep in the first six months is in a cot in the same room as the parent or carer.
And in 2014, NICE updated its recommendations about co-sleeping, to say that although Sids is rare, it does happen more often when parents co-sleep.
The NCT antenatal group says parents who co-sleep should make sure their baby cannot fall out of the bed, or become trapped in any way. They should use sheets and blankets rather than a thick duvet, and make sure bedding never covers a baby's face or head.
Babies should be kept away from pillows, and experts say parents should never fall asleep with a baby on a sofa or armchair.
Shona Haigh, a first-time mother, co-sleeps with her four-month-old daughter Ava.
She says her friends encourage her to get her daughter to sleep in a cot - but Ava simply cries when she is left alone.
"She starts kind of choking herself and coughing and she's clearly not happy. I'd much rather my baby be happy in my arms while I'm awake and happy with me in bed while we're sleeping."
She say Ava sleeps in a sleeping bag with her mum and dad on either side of her.
"It is completely natural for us to want our babies next to us and for our babies to want to be next to their mothers," she says.
She says she has been given "no advice" about how to co-sleep safely.
"It was a brushed-off conversation," she says.
"I had no information from my health visitor and midwife. She told me that they wouldn't give me any information because they don't want you doing it."
Elaine McInnes, who advised NICE, says advice on co-sleeping is not reaching parents.
She says some parents still feel "judged" about co-sleeping and often lie to health visitors if they are doing it.
As a result, she said, guidance about how to minimise the risks of co-sleeping isn't getting across.
The problem is exacerbated by falling numbers of health visitors working in the UK, she adds.
'Tearing families apart'
Meanwhile, Dawn - who has since had a baby girl named Faye - says her "entire chest aches" every time she thinks about Fern's death.
Her death led Dawn to isolate herself from her friends and the majority of her family.
She hopes speaking out about co-sleeping will raise awareness.
"It can happen to anyone," she explains.
"Anyone can get a leaflet with guidelines about how your baby should sleep, but I think putting a face to it [makes people realise] it does happen, it's still tearing families apart."
Watch the Victoria Derbyshire programme on weekdays between 09:00 and 11:00 on BBC Two and the BBC News channel.