The discussions that I have with caregivers are sometimes limited by a lack of clear and evidence-based guidelines. Using the available data and my clinical judgement I attempt to communicate this uncertainty and, hopefully, provide enough information to make an informed decision. Sadly, I can’t always rely on the internet for help. Even worse is when online misinformation comes from what should be a reliable source, such as a major academic medical facility.

The most egregious offender is Cleveland Clinic, and we have sacrificed many electrons pointing out problems with their social media and patient/parent education efforts over the years. Most of the time this has involved various promotions of implausible and even disproven interventions such as acupuncture and…(sigh)…functional medicine. On this go round, however, the focus of my attention is a recent article posted online and promoted on Twitter that discusses a subject that I’ve tackled before, the choices parents make regarding how they put their babies down to sleep.

A little over a year ago I wrote on the issue of sleep sack safety versus traditional infant swaddling during sleep. In that post, I took the author of a Today’s Parent article to task for promoting inaccurate information. Call me naïve, but I usually hold world class academic medical centers to a higher standard than parenting magazines. So I was shocked, shocked I say, to see an article put out by their pediatric institute that really dropped the ball.

Published on June 3rd, the Cleveland Clinic article poses the question, “Are Sleep Sacks Safe for Babies?” The title alone is potentially problematic. Many people who just see the title as they scroll through their feeds could, after a bit of time has passed, recall only that they saw something about sleep sacks being unsafe, which is the opposite of what the article claims. It would have been better to use a title that clearly stated the conclusion, which is that sleep sacks are safe options for infant sleep.

My problem with this short article isn’t that I think sleep sacks aren’t safe. The issue is that it pushes the questionable narrative that swaddling is dangerous. It isn’t. There is some nuance, which I’ll get into, but it is wrong to make a blanket statement that swaddling is somehow going to kill babies. See what I did there? The article also makes some odd claims that might leave parents confused.

Feel free to read the short article I’m breaking down here, but I will be quoting liberally.

But a sleep sack isn’t a mere fashion statement. View it more as a layer of protection. A 2019 analysis found that infant sleep sacks “are as safe, if not safer, than other bedding” when it comes to preventing sudden infant death syndrome (SIDS).

Why are sleep sacks so effective? Pediatrician Heidi Szugye, DO, IBCLC, offers an explanation.

I think a lot of people reading that will come away with the wrong idea about sleep sacks because it is misleading. Sleep sacks do not lower the risk of SIDS independently. They aren’t magic. The 2019 paper that they reference doesn’t add anything new to what we already know based on a more focused 2016 meta-analysis published in Pediatrics. As I wrote last year, the question is really about the safety of swaddling and if a sleep sack is a safer option, rather than whether or not sleep sacks independently reduce the risk of SIDS:

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 a baby old enough to roll over is swaddled.

As you can see, swaddling can be considered an independent risk factor for unexpected death during sleep, albeit a fairly minor one. But it is really only dangerous if you combine swaddling with other modifiable risk factors, specifically when a very young baby is also placed face down to sleep or, to a lesser extent, when a baby is old enough to wiggle themselves into a prone position on their own. This skill typically develops at around 4 to 6 months of age, which is actually past the peak of SIDS incidence at 2-3 months. Though the exact mechanism for why this raises the risk of death isn’t known, it is reasonable enough to assume that a prone baby whose arms are wrapped snugly against their chest might have difficulty moving their face away from a mattress or other plush surface that shouldn’t be near a sleeping baby, like a large stuffed animal or a crib bumper.

Two infants that are put down to sleep following all safe sleep guidelines, with one being placed in a sleep sack and the other in a swaddle blanket, are both extremely unlikely to die unexpectedly in their sleep. The exact same can be said when comparing babies in sleep sacks to babies put down for sleep in just an outfit. The baby in the sack is not safer than the baby in an adorable onesie.

A sleep sack is basically a way to safely keep your child warm while they sleep. It truly is designed as a wearable blanket, with your baby’s torso, legs, feet and teen-tiny toes housed within the sack.

The garment should be sleeveless, allowing those little arms and hands to move freely without any restrictions.

Most babies don’t have any difficulty maintaining a normal body temperature once they have successfully transitioned after delivery and have begun to feed. Unless they are significantly premature, growth restricted, or left soaking wet after a bath on the back porch during a blizzard, there is very low risk of harmful hypothermia. They would be just fine in one thin layer of clothing. The purpose of a sleep sack, when they have wings, or a swaddle blanket is not to keep a baby warm but to help them sleep by reducing general stimulation and limiting reflexive arm movements.

Sleep sacks with wings work essentially like a swaddle blanket. The difference is that when a baby busts out of them, the wings fall to the side and can’t be accidentally pulled up over the face. Seep sacks that lack wings, like the ones recommended in the article, do not help an infant sleep. They don’t really do anything.

Sleep deprivation is a very underappreciated complication of the postpartum period and beyond, and it can contribute to numerous bad outcomes. Impact injuries can occur if a baby is dropped when a caregiver falls asleep holding them. There is increased risk of car accidents, as well as non-accidental trauma when an exhausted and stressed caregiver is faced with a baby that is difficult to calm. Poor sleep also plays a role in postpartum depression and psychosis, and it even increases the risk of SIDS or suffocation because exhaustion interferes with following recommended safe sleep guidelines. The Cleveland Clinic article completely disregards the potentially life-saving benefit of improved maternal rest.

The article goes on to list 3 benefits of sleeveless sleep sacks. According to the author, sleep sacks provide warmth without the risk of placing a blanket around a baby that could become a suffocation risk. Again, there is some plausibility to this and pediatricians don’t recommend loose blankets during sleep. But as I stated earlier, when it comes to a blanket snugly swaddled around a baby, it’s not so clear that the risk of unexpected death during sleep is much different unless said baby is also placed face down or old enough get that way on their own.

The second benefit mentioned is essentially an extension of the first. The author points out that sleeveless sleep sacks allow free movement of a baby’s arms and the ability to use them to move into a safer sleep position should they roll on to their tummy. This is true. Pediatricians also don’t recommend restricting the arms of babies who can turn over. These babies are just as safe in a sleeveless sack at that point as they are out of one, however. Parents should be on the lookout so that they can determine when to stop swaddling, whether they use a blanket or a sleep sack with wings.

The final benefit involves a reduced risk of a condition known as developmental dysplasia of the hips, or DDH. DDH is an instability of the hip joint that allows for dislocations and can result in significant long-term disability, even a need for hip replacement in early adulthood. It is most common in female infants and infants who were breech late into pregnancy, but genetics and tight swaddling of the lower extremities that forces the legs into a straight extended position are risk factors as well. Sleeveless sleep sacks do allow room for babies to move their legs, and that does lower the risk of DDH, but a baby can easily be swaddled in a hip friendly fashion.

In the final section of the article, the author attempts to specifically address the issue of swaddling, which they admit is very common, versus putting a baby to sleep in a sleeveless sack.

The snug feeling is supposed to mimic the feeling of being in the womb. Done correctly and with adult monitoring while in use, swaddling can be an effective technique to calm infants and promote sleep, according to the AAP.

Don’t anthropomorphize babies…they hate that! Claims of mimicking the womb are a convenient framework but they are just an assumption and honestly, they don’t make much sense. It’s true that as a baby nears delivery deep into the 3rd trimester, they do have somewhat restricted movement of their arms and legs. But a term fetus close to delivery still moves around quite a bit. Plus, they are subject to being jostled around as their mother moves about during her day. It’s hardly comparable to the nearly motionless state of a sleeping and swaddled infant lying on a still, firm mattress.

I’m not sure what they mean by “adult monitoring”. Are they saying that an adult must be awake and directly observing a swaddled baby at all times? If so, that’s terrible advice. Caregivers need sleep and they should be reassured that they can sleep when their baby sleeps. Monitoring using technology is an equally unsound recommendation. These devices have never been shown to prevent unexpected death during sleep and are a significant source of caregiver anxiety that can result in false alarms and unnecessary trips to the emergency department in the middle of the night.

The remainder of the article repeats earlier admonitions to avoid putting a swaddled baby face down or using a swaddle once a baby can roll over on their own. And once again, I agree. Don’t do that.

In the grand scheme of things, this article isn’t nearly as bad as the nonsense put out by Mark Hyman and other promoters of pseudomedicine gainfully employed by Cleveland Clinic. Still, I expect better education than this. In particular, it’s unfortunate that there wasn’t any discussion of the importance of caregiver sleep. It is critical to take both risks and benefits into account, and in my opinion sleeveless sleep sacks are fine but any benefit is likely outweighed by the harm from sleep deprivation. Leaving this out of any discussion with caregivers means that they aren’t truly making an informed decision.

Author

  • 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.

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.