Swaddling and Sleep
To reduce crying in irritable babies and to prolong sleep in babies who seem to wake up all the time, parents in many parts of the world swaddle their babies when putting them down to sleep. This custom of wrapping babies snugly in light cloths or sheets has been used for centuries. Researchers at the Pediatric Sleep Unit of the University Children’s Hospital in Brussels, Belgium decided to use their modern sleep lab to measure the effect of swaddling on sleep. They were particularly interested because swaddling while sleeping on the back has been said to reduce the risk of SIDS. Up to 30 percent of babies are still placed face down to sleep, despite a massive education campaign. One of the main reasons parents give for this dangerous choice is that their babies cry more on their backs and don’t sleep as well. If swaddling babies sleeping on their backs reduces crying and improves sleep, it might help promote sleeping on the back, further reducing SIDS, while making life more pleasant for babies and their parents. What did the researchers find?
The somewhat surprising results were published in the May 2005 Pediatrics. The babies in the study ranged from 6 weeks to 16 weeks old. The study started at 9 p.m. Half of the babies were placed on their backs and allowed to fall asleep without swaddling. Then at 1:01 a.m., whether they were awake or asleep, they were “tidily wrapped” in a small bed sheet to prevent them from moving their arms or legs, and returned to their backs for the rest of the night. The other half of the babies were swaddled at the beginning of the night, and unrestrained at 1:01 a.m. Throughout the night, all the babies were carefully monitored with EEGs (measuring brain activity), EKGs (heart activity), electrooculograms (eye movements), electromyograms (muscle activity), plethysmography (breathing movements), actigraphs (overall movement), thermistors (air flow from the mouth and nose), pulsoximeters (oxygen saturation in the blood), and rectal probes (core body temperature). All of this detailed information was collected and collated on computerized polygraphed recorders for a total of 16 babies.
On average, the babies did indeed sleep significantly better for the half of the night that they were swaddled. The swaddled babies spent significantly more total time asleep. They had fewer spontaneous awakenings. When the swaddled babies did wake up (which we all do, several times each night), they fell back asleep in an average of only 30 seconds (ranging between 0 and 7 minutes). The heart rates of the swaddled infants were also more responsive (a good thing!). There was no change in core temperature or oxygen saturation.
Nevertheless, the swaddled babies awakened more easily to outside noises! While the babies were dreaming (REM sleep), the researchers played 3-sec bursts of white noise at increasingly loud volumes to see what it took to get the babies to open their eyes. The babies awoke at significantly lower volumes when they were swaddled than when they were unrestrained. The swaddled babies awoke at an average volume similar to a moderately loud conversation. Their heart rates and blood pressures responded at even lower volumes. Perhaps this increased responsiveness to the outside environment makes SIDS less likely.
With only 16 babies, and only 4 hours each of swaddling time, the study was too small and too brief to make general recommendations about ongoing sleep habits. But the possibility of promoting both better sleep and increased responsiveness is exciting. And this high-tech, 21 st century evidence seems to support and explain generations of parenting wisdom.
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Alan Greene MD FAAP
Reviewed by Alan Greene MD FAAP December 2005
| May 28th, 2005 at 12:37 pm
Hi, Dr. Greene!
What an interesting study. I come from a culture where babies were historically swaddled (Russia), although it’s not popular now. My daughter slept completely swaddled until she was 5 months old, and partially swaddled (legs only) until she was 20 months old. It made her very comfy.
Katya
| December 26th, 2005 at 8:07 pm
I also come from a culture where swaddling has been around since “immemorial” (Cree nation in Quebec) We even have a special swaddling “sack” I could call it. It;s called a wesepsuuyan, some are even made out of Moose hide. my 15 month old slept in it untill he was about 6 months old and now my newborn is sleeping in it..right now! They both love/d it!
| January 31st, 2006 at 9:59 pm
Hi Dr. Green,
When my daughter was first born I didn’t think she liked to be swaddled. But she slept horribly. After about 3 weeks I started to swaddle, she was sleeping throught the night at one month and I think it was due to being wrapped tight like in the womb. I still keep her swaddled but she sometimes likes to wiggle her arms out.
| July 19th, 2006 at 5:27 pm
Dear sir, I am very much disturbed that my son is very tightly wrapping my 8 month old granddaughter. The only thing which she can move is her head. She is very docile and very small for her age. when I told him that this is a form of cruelty, he virtually told me to mind my oun business. If he were not my son. I would report him to child protective services. I am a mother of 6 and swaddled my infants for a very short time, because I realized that they were snug in the womb. But this little baby is being stifled. Any advice for me? Janiece from Daly City, CA.
| May 8th, 2007 at 8:28 am
Hi Dr. Greene. With two small children under two, whom both have been swaddled, I find that our experience is comparable to that of the study. We are currently trying to wean our 4 month old, as he wakes (which can be often) when his arms become free. Any suggestions to help with this transition? Thanks!
| December 13th, 2007 at 11:29 am
My baby is nearing 6 weeks old and he has some trouble with waking in the night/shifting needlessly from sudden jolts he makes with his arms and legs. He was like this in the womb, and is nearly always like this whatever activity we’re doing. But, he absolutely hates having his limbs even lightly held to keep him from jolting about so actively. I once laid him to nap on his front and observed carefully; he slept longer and with little movement. Is it possible to take other measures other than swaddling? Are there reasons not to swaddle or (short of sounding paranoid, is it possible to harm my child psychologically if I swaddle him against “his will” -I was a swaddled baby and feel awful if my limbs are restricted in any way!).
| August 26th, 2009 at 8:51 pm
I have been swaddling my baby since birth to sleep on her back. Now at 2 months old, I feed her at 8:30 pm, burp her, swaddle her, and then she sleeps through the night. I bought the kiddopolis swaddle, all you do is put baby in, and then velcro the sides to stay. I feel more comfortable having the velcro that won’t come loose over a blanket that could possibly come loose and restrict her breathing. The only problem is that she does not sleep soundly at naptime without being swaddled.