Erin Flynn-Evans, PhD, MPH
Apr 27
Updated: Apr 28
Updated and revised from an earlier version to reflect new information as it has become available
Over the years there have been numerous innovations and fads that purport to help babies sleep. Some of these, like Houdini-proof swaddles and basic cotton sleep sacks, have become nursery staples that actually do improve sleep. On the other hand, other devices have fallen out of fashion due to limited benefits or have been recalled over significant safety concerns. The latest trend in baby sleep attire is weighted sleep sacks, but do they live up to the hype?
Weighted blankets first emerged as a tool to help caregivers calm children with sensory processing disorders. The majority of scientific literature supporting the use of weighted blankets comes from studies of school-aged children with autism spectrum disorder and attention deficit hyperactivity disorder. In these populations, studies are mixed about whether they actually improve sleep outcomes. A few studies found that children with autism experienced improved sleep maintenance and a faster time to fall asleep. However, the studies showing positive benefits often only included a few children, while more rigorous studies have typically not found any benefits to sleep. A recent systematic review, which is a methodological approach to reach a conclusion based on compiling the results of many studies, found that there is some evidence to support that weighted blankets reduce anxiety, but "not enough evidence" that they improve sleep (Eron et al. 2020). However, several studies have shown that despite no observable positive benefits, children and parents like using weighted blankets.
There are currently no peer-reviewed studies examining the use of weighted blankets or sleep sacks in medically typical infants or toddlers. One study using weighted blankets for NICU newborns with Neonatal Abstinence Syndrome (i.e., babies born with withdrawal symptoms due to maternal opioid use) found that covering an infant with a weighted blanket for 30 minutes at a time reduced the baby's heart rate and symptoms of withdrawal (Summe et al. 2020). That study also found that the babies did not experience a significant increase in body temperature or change in respiratory rate while wearing the weighted blanket. However, that study did not assess sleep outcomes.
The main takeaway from the scientific literature is that there is no evidence to support the use of weighted sleep sacks during sleep for medically typical children. There is also concern that babies could become entangled or that the pressure from a weighted sleep sack could interfere with breathing. There have already been a number of deaths reported in children wearing these sleep aids. Furthermore, there are no studies examining how these sleep sacks affect babies when they are used for long durations of time (hours overnight for weeks on end). For these reasons, the American Academy of Pediatrics recommends against using weighted sleep sacks, as does the Consumer Product Safety Commission.
Believe it or not, companies do not have to go through any sort of official safety certification to sell infant sleep attire (sleep surfaces, such as cribs and bassinets do have specific CPSC safety requirements that you can read here). You might assume that because something is for sale it is safe, but the reality is that business is often ahead of science. Below are some of the safety concerns with using weighted sleep sacks:
Weighted sleep sacks are heavier than cotton sleep sacks and may not allow heat to escape from your baby's body. Overheating is a serious safety concern for babies. See more on dressing your baby for different temperatures here.
We haven't seen any reports of babies becoming entangled or stuck on their bellies in weighted sleep sacks, but we know that some babies are very mobile and have the potential to get tangled.
Although the NICU study didn't find any changes in respiration, the babies in that study only wore the weighted blankets for a short duration of time and they were always supervised. They also did not wear the weighted blanket during sleep. Respiration changes during sleep and there are no studies that have examined infants' breathing patterns during sleep while wearing a weighted sleep sack.
Although there hasn't been a lot of research into this topic, we would not recommend using a weighted sleep sack. The risks simply do not outweigh the (unknown and theoretical) benefits. Remember also that most sleep problems aren't resolved through a "quick fix," like changing sleep attire.
https://www.cpsc.gov/SafeSleep
Moon, R.Y., Carlin, R.F., Hand, I. and Task Force on Sudden Infant Death Syndrome, 2022. Sleep-related infant deaths: updated 2022 recommendations for reducing infant deaths in the sleep environment. Pediatrics, 150(1).
Summe, V., Baker, R.B., Eichel, M.M. and Cleveland, L., 2020. Safety, Feasibility, and Effectiveness of Weighted Blankets in the Care of Infants With Neonatal Abstinence Syndrome: A Crossover Randomized Controlled Trial. Advances in Neonatal Care, 20(5), pp.384-391.
Eron, K., Kohnert, L., Watters, A., Logan, C., Weisner-Rose, M. and Mehler, P.S., 2020. Weighted blanket use: a systematic review. American Journal of Occupational Therapy, 74(2), pp.7402205010p1-7402205010p14.
Gringras, P., Green, D., Wright, B., Rush, C., Sparrowhawk, M., Pratt, K., Allgar, V., Hooke, N., Moore, D., Zaiwalla, Z. and Wiggs, L., 2014. Weighted blankets and sleep in autistic children—A randomized controlled trial. Pediatrics, 134(2), pp.298-306.
France, K.G., McLay, L.K., Hunter, J.E. and France, M.L., 2018. Empirical research evaluating the effects of non-traditional approaches to enhancing sleep in typical and clinical children and young people. Sleep medicine reviews, 39, pp.69-81.
Bolic Baric, V., Skuthälla, S., Pettersson, M., Gustafsson, P.A. and Kjellberg, A., 2021. The effectiveness of weighted blankets on sleep and everyday activities–A retrospective follow-up study of children and adults with attention deficit hyperactivity disorder and/or autism spectrum disorder. Scandinavian Journal of Occupational Therapy, pp.1-11.
Gee, B.M., Peterson, T.G., Buck, A. and Lloyd, K., 2016. Improving sleep quality using weighted blankets among young children with an autism spectrum disorder. International Journal of Therapy and Rehabilitation, 23(4), pp.173-181.
Gee, B., McOmber, T., Sutton, J. and Lloyd, K., 2017. Efficacy of weighted blankets for children with autism spectrum disorder, sensory overresponsivity, and sleep disturbance. American Journal of Occupational Therapy, 71(4_Supplement_1), pp.7111515242p1-7111515242p1.