As a newborn hospitalist, a large part of my job involves educating parents on a variety of newborn care topics. One of the most important discussions that I make a point to have even with experienced caregivers involves safe sleep. Every year in the United States around 3,500 infants die unexpectedly during sleep and there are a number of modifiable risk factors that can play a role in these tragic outcomes.

I take this aspect of my job very seriously, and not just because it might save lives. Educating parents on ways to make their child safer during sleep reduces anxiety and helps them to get some much-needed rest themselves. Caregiver anxiety reduction and improved sleep has many positive health benefits for all involved parties and should never be underestimated as an intervention.

As much as I am pleased when caregivers are empowered and their fears calmed by legitimate medical information, I am equally frustrated when I encounter misinformation that does the opposite. Longtime SBM readers will know that I often focus my ire on chiropractors who swerve far out of their lane by giving pediatric medical advice. For example, I recently spent some time watching a number of videos produced by chiropractors who promote the absurd idea that infants are being harmed by improper diaper changing technique. I watch videos like this and have to wonder if these people actually know any babies.

Some of the discussions I have with parents are complicated by a lack of clear guidelines based on solid evidence. I do my best with the available data and I make sure to communicate this uncertainty to caregivers while giving them the tools to make an informed decision. Unfortunately, the internet is full of information that doesn’t always help clear up these complex issues.

A few weeks ago I encountered an example of this in the form of an article on safe infant sleep published by Today’s Parent, which bills itself as “Canada’s #1 source for parenting content that informs, inspires and builds a sense of community.” While I wouldn’t put it in the same league as infant chiropractic, it has a few problems. Here goes.

In the article, author Vanessa Milne does what many authors of such pieces do and opens with a question: Is swaddling dangerous? Betteridge’s law of headlines, which states that “any headline that ends in a question mark can be answered by the word no”, may have been proven wrong, but it still often comes across as clickbait. Nobody is perfect, however. Unfortunately, many people won’t read past the first paragraph and will come away thinking that swaddling should absolutely be avoided. Even when reading the entire article it is still a bit confusing.

Another common approach to medical articles written for the lay public is opening with an anecdote. In Milne’s article, the anecdote involved a confused parent:

When Melissa Romain had her first baby at a Toronto hospital in 2016, the nurses demonstrated how to swaddle him and encouraged her to continue doing it at home. But by the time she had her second baby four years later, things had changed. The nurses swaddled her baby the whole time they were on the maternity ward; then, as she was being discharged, they told her she shouldn’t swaddle at home because it was too dangerous. They said this was because the baby was under closer supervision in the hospital, but Romain says there was plenty of time that she and her baby were alone together in her room. “I was confused and a little frustrated,” says Romain. “Nobody explained why swaddling is no longer a best practice. They just said that this is how it is now.”

I get why this was done, of course. Stories are powerful and they are meant to be a hook to help reel the reader into the rest of the article. And this is a good hook. A lot of people will read it and worry that they are putting their baby at risk. Or they may worry about the baby of a loved one. They may be concerned that hospitals are giving confusing or even risky advice to caregivers. But it is unlikely that this one woman’s experience can be generalized to all or even most hospital nursery care. And as I’ll explain, swaddling can be done safely.

In the article, Milne claims that the Registered Nurses Association of Ontario advises against swaddling. But they don’t. In their most recent guidelines on safe sleep, the RNAO states that ‘There is currently no evidence on the “safe way” to swaddle an infant, and hence caution regarding swaddling should be expressed…’, which is accurate if not a bit melodramatic.

The RNAO points out that a swaddle can potentially become a loose blanket that could be a risk factor during sleep, and that excessive bundling can overheat a baby, which is also a risk factor for death during sleep. But they don’t advise against swaddling. I point these concerns out to parents as well, but there is actually data to support a nuanced position that takes risks AND benefits into account, rather than a blanket proscription. I’ll get to that data shortly.

Milne also claims that Perinatal Services BC advises against swaddling. This is true, but needs some context. When looking into their specific recommendations, the first document I came across was a 2015 Newborn Care Guideline where swaddling is mentioned only twice. The first time is when it’s recommended for newborn pain control and the second is under the heading of heat control in infants where skin-to-skin care is recommended instead. But this document only addressed care in the newborn nursery.

I eventually was able to find the PSBC “Safe Sleep Environment Guideline” that Milne was referring to, which was released in 2011. It is aggressively anti-swaddling, claiming that it can cause overheating, decreased arousal and subsequent death from SIDS, chest infections, restricted breathing, and inability to use the arms to move away from harm. It also claims that there are very few benefits from swaddling and it is essentially unnecessary. It’s hyperbolic and I don’t agree with their approach.

PSBC also puts out a brochure for families aimed at educating them on safer sleep. It also includes a section on swaddling that repeats the previously described risks. Of note, it implies that skin-to-skin care is more desirable than swaddling. In my post on this practice, conveniently linked to above, I discuss the serious risks of skin-to-skin care that are often ignored.

In Milne’s Today’s Parent article, a nurse is quoted claiming that swaddling can result in a loose blanket that may cover a sleeping baby’s face. If this were to happen, I agree it would be concerning. We strongly recommend avoiding loose blankets, stuffed animals, or anything that might find itself blocking a baby’s supply of fresh air. But does that mean putting a baby down to sleep in a swaddle results in a higher chance of unexpected death during sleep? Are the warnings of PSBC are legitimate?

This question was actually addressed in a 2016 meta-analysis published in Pediatrics, but to be completely honest it’s still not entirely clear. The answer is probably no, however, as long as you avoid a couple things. It is difficult to study something as complex as infant death during sleep, and data is necessarily retrospective. So it will likely always be challenging to draw firm conclusions. The 2016 Pediatrics analysis of several studies looking at swaddling and its relationship to SIDS showed that swaddling does not appear to significantly increase the risk of death during sleep except for when a swaddled baby is placed face down (please never do this) or when an baby old enough to roll over is swaddled.

The Today’s Parent article repeats the concern that swaddling a baby may lead to overheating, but this is easily avoided by using the one to two thin layers rule and educating caregivers on appropriate room temperature. Claims that swaddling may restrict breathing and increase the risk of chest infections are just not true. It is true, however, that restrictive swaddling that forces a baby’s hips into extension can increases risk of hip dysplasia, so don’t do that.

The article correctly points out that swaddling can improve baby sleep (which I’ll add can improve caregiver sleep and thus numerous other outcomes), and that the American Academy of Pediatrics and Canadian Pediatric Society say that swaddling is low risk if done correctly. Milne also provides some helpful information on proper swaddling and safe sleep positioning. The article ends with the very important reminder to check with a baby’s healthcare provider there are questions.

One statement towards the end was just…odd. A Toronto pediatrician is quoted claiming that there are “some infants who shouldn’t be swaddled under any circumstances, such as babies who are very jaundiced or underweight”. I am wholly unfamiliar with this recommendation and can’t think of any reason why this would be true.

So the bottom line, in my opinion, is that swaddling is fine. There is a very small increased risk of SIDS but that data was based on a tiny number of SIDS cases in swaddled babies and the biggest risk comes when a baby is placed face down. The benefit of improved sleep, both for the baby and the parents, outweighs the risk when swaddling follows the recommendations given by the AAP.

The studies performed so far haven’t looked at how the babies who died during sleep were swaddled. Common sense says don’t make it too loose, don’t use thick or multiple blankets, and don’t swaddle once a baby is rolling over on their own. And again, always place a baby on their back to sleep.

Sleep sacks can substitute for a swaddle. These typically involve zippers, Velcro, or the dreaded snaps, and thus can’t become a loose blanket. Use the kind that have wings so that baby’s arms can be restricted to get the same benefit as from swaddling. And of course, the same safety rules apply.


Posted by Clay Jones

Clay Jones, M.D. is a pediatrician and a regular contributor to the Science-Based Medicine blog. He primarily cares for healthy newborns and hospitalized children, and devotes his full time to educating pediatric residents and medical students. Dr. Jones first became aware of and interested in the incursion of pseudoscience into his chosen profession while completing his pediatric residency at Vanderbilt Children’s Hospital a decade ago. He has since focused his efforts on teaching the application of critical thinking and scientific skepticism to the practice of pediatric medicine. Dr. Jones has no conflicts of interest to disclose and no ties to the pharmaceutical industry. He can be found on Twitter as @SBMPediatrics and is the co-host of The Prism Podcast with fellow SBM contributor Grant Ritchey. The comments expressed by Dr. Jones are his own and do not represent the views or opinions of Newton-Wellesley Hospital or its administration.