NEW YORK - Many parents put soft bedding such as pillows and blankets where babies sleep, despite warnings that the cushioning increases the risk of infant death, a US study said.

That's because many are under the impression that a soft sleeping environment means the baby will be more comfortable or protected from injuries, said Rachel Moon, from Children's National Medical Center in Washington D.C. and one of the study's authors.

"When it comes to babies' sleep environment, soft is not safe, it's actually dangerous," she added.

Researchers know that black babies are at least twice as likely as white, Latino and Asian babies to die of accidental suffocation, strangulation or sudden infant death syndrome (SIDS), also known as "crib death."  

While some of that higher incidence may be linked to genetics, some is also likely due to parents unknowingly putting infants in a dangerous sleeping place, Moon added.

To find out whether black families know about the risks, Moon and her colleagues conducted one-to-one interviews and small group discussions with 83 black mothers in Washington D.C. and nearby Maryland. All had a new baby at home.

The researchers asked women if they used soft bedding and bumper pads in their baby's crib or other sleeping location, and why or why not.

While the interviews were only done with black mothers, parents of all races may misinterpret a pediatrician' s recommendations or what constitutes a safe sleeping environment, said Debra Weese-Mayer, a pediatrician at Northwestern University Feinberg School of Medicine.    

According to findings published in Pediatrics, more than half of the mothers reported using soft bedding for their baby, telling researchers they wanted to make sure the children were comfortable and warm. They also said they used pillows as a barricade on beds or sofas, or to prop babies up.

"We were surprised that people use (soft bedding) because they think it's going to make their baby safer," Moon told Reuters Health.

"We weren't that surprised that people use it to make the babies comfortable."

Some mothers thought doctors' recommendations to use a "firm sleep surface" included a bed where a sheet was tucked tightly over pillows -- but that's still a dangerous sleep situation, Moon and her colleagues warned.

The mothers also used bumper pads on cribs if they worried that a baby would hit its head on the railings or get an arm or leg stuck. But as with pillows and blankets, bumper pads pose a suffocation risk, Moon said, adding that there really isn't any need for them -- especially for very young babies.

SIDS kills about 2,500 babies every year in the United States. Putting babies to sleep on their sides or stomachs is known to increase the risk, as is having them sleep in their parents' bed.

Fern Hauck, a SIDS researcher at the University of Virginia in Charlottesville, said she understood the desire to make babies comfortable with soft bedding in the hope that they'll sleep better and longer.

"But babies can pretty much sleep anywhere. If you get them used to a firm crib mattress, they're going to sleep fine on a firm crib mattress," she added.

All the experts agreed that awareness of the dangers needs to be raised across the board.

"(The study) is a very humbling lesson that even though we think we're giving a very clear message, if the parent and the caretaker are interpreting it in a way different from what we intended, we're not doing a very good job," said Weese-Mayer.

"If it can save some babies because we do a better job of translating our recommendations, that's wonderfully important."