(CNN) Despite a 23-year campaign urging that babies be put to bed on their backs, only 43.7% of US mothers report that they both intend to use this method and actually do so all the time, according to a new study .

The study, published Monday in the medical journal Pediatrics, surveyed 3,297 mothers, of whom 77.3% reported that they usually -- but not always -- put their babies to sleep on their backs.

"What was new and hadn't been explored before was this idea of what people intended to do versus what they actually do," said Dr. Eve Colson, professor of pediatrics at Yale School of Medicine and co-author of the study. "What we found was that people intended to put their baby on their back but didn't always do that."

Another finding was that those who felt the baby's sleeping position was not up to them, but rather the baby or another family member, were more than three times as likely to place the baby on its stomach.

The two main critiques of back sleep were the fear that the baby might choke and that it's less comfortable than having them sleep on their stomachs, Colson said.

These beliefs could be from lack of education, as well as cultural and familial influences, said Dr. Robin Jacobson, a pediatrician at Hassenfeld Children's Hospital at NYU Langone Health, who was not involved in the study. Many prior generations had their babies sleep on their stomachs, she said.

"Grandmothers and aunts and everybody have told (mothers), if they have babies sleep on their bellies, they're more comfortable; they're not going to choke," she said. "And because of that, a new mom who doesn't really have a lot of information is using information from everybody else in their life."

A racial disparity

The new research oversampled Hispanic and African-American women in order to make adequate comparisons across racial groups, the authors said. African-American mothers were reported to be the least likely to put their babies on their backs, compared with other demographics.

There were about 3,700 sudden unexpected infant deaths in the US in 2015, according to the CDC . SIDS account for 1,600 of those while 1,200 are due to unknown causes and 900 were due to accidental suffocation and strangulation while in bed. The sudden unexpected infant death rate of non-Hispanic black infants was 170.2 per 100,000 live births between 2011 and 2014, more than twice that of non-Hispanic white infants (83.8 per 100,000).

The elevated rate has a lot to do with societal norms, said Dr. Rachel Moon, a pediatrician who has studied SIDS in African-American communities.

"There's very much a culture of putting babies on their stomach in an African-American community," said Moon, who was not involved in the new study. "There's a lot more dependence on grandmothers and other senior family members as trusted sources, and lots of times, the information that you get from your family members is more persuasive than what you get from physicians and other sources."

Moon also said that parents perceive babies to be uncomfortable if they are frequently waking or crying while on their backs, so they let the child determine the sleeping position.

"I think the fact that parents don't feel like they have control is something we can talk about," she said. "It's often the child that's the queen or the king of the household. And I think parents often forget that they're the adults of the household, and they can actually make decisions if they think they're right for their children."

Preventing SIDS

The latest guidelines from the American Academy of Pediatrics advise that parents sleep in the same room -- but not the same bed -- as infants until the child is at least 6 months old.

Babies should be placed on their backs on a firm sleeping surface with a tight-fitted sheet and no pillows or blankets, to prevent suffocation and overheating. They should never be put on couches, sofas or cushioned chairs to sleep.

But what's the best way to ensure that everyone obtains access to this information?

The key is educating parents' friends and families, facilitating open conversations about infant sleep and encouraging the media and advertisers to display images of safe sleep practices, according to an editorial accompanying the new study.

It also noted that health care providers should be consistently communicating clear messages about safe sleep guidelines.

"Every single health care provider needs to be saying the same thing," Moon said.

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The study found that those who received advice from their doctor consistent with the guidelines were less likely to place a baby on its side or stomach to sleep.

"You don't really realize when you're doing this day in and day out that moms really respect you and really listen to what you're saying and even would agree with you over their own mother or somebody else in their life," Jacobson said of doctors. "So I definitely think this needs to be publicized again in the American Academy of Pediatrics and with pediatricians to really push the Safe to Sleep program."