Are Baby Sleep Sacks with Sleeves Safe?

To answer this question, we must first examine the premise, "What makes any sleep sack (also known as a wearable blanket) safe?" This is a question many parents are asking right now, particularly in light of the attempted rewriting of ASTM standards and the updated American Academy of Pediatrics (AAP) guidelines regarding swaddles and sleep sacks. Baby sleep safety is easily the most important—and perhaps also the most difficult and confusing—area of understanding and implementation that parents and caregivers come across within their baby's first year of life. So let's dive in and answer the question, "What makes an infant sleep sack safe?"

Ensure that the sleep sack allows for the ability to regulate temperature

One way to determine if the wearable blanket is safe to make sure that there are different TOG options available for varying seasons and temperatures. The TOG factor (or Thermal Overall Grade) is a rating process that measures warmth and calculates how quickly a fabric loses heat. Basically, the higher the TOG, the warmer the fabric. The TOG of the fabric is important for choosing the appropriate wearable blanket for your baby, depending on the temperature in your baby's sleeping space.

Fabric with a higher TOG (2.5-3.5 TOG) is better for cooler temps (68° and lower), and fabric with a lower TOG (0.5-1.0 TOG) is more appropriately suited for warm to moderate temperatures (68°F and higher).

Since younger babies may have a harder time regulating temperature, we have made the decision to only create swaddles, and wearable blankets for babies 0-3 months that fall in the 0.5 TOG range. We have also created especially designed bodysuits and footie pajamas to provide babies with a safe alternative to swaddling in case parents don’t want to layer baby on top with a wearable blanket in the warmer months, but still want the coziness that swaddling provides. This way, baby can be kept cool and comfortable and parents can layer under as needed without having to worry about the potential concerns of overheating. 

Ensure that the sleep sack is form-fitting

Another way to determine safety for the wearable blanket you are considering for your baby is to make sure that the item hugs your baby's body around the shoulders, neck, arm openings, and sleeves (if included). These areas should be snug around your infant's torso to prevent the sleep sack from sliding off your baby's body as they move around in their sleep. Make sure you pay special attention to how they fit on your baby's body to ensure a safe night's sleep.

Ensure that the the sleep sack isn't too large or long

This point is especially important for younger and smaller babies. You will notice that as our wearable blankets start out for babies 0-3 months, the smaller the range of weight they can cover. This is strategic in terms of safety. Any extra fabric can hinder a baby's ability to move freely, and smaller babies may have a difficult time maneuvering themselves into a safe position with excess fabric gathering at the bottom or sides of the sleep sack being used. As babies get older and bigger, they gain more dexterity, so you may find that the weight ranges are larger and cover longer age periods as well. 

Ensure that the sleep sack isn't weighted

The AAP updated their safe sleep guidelines in 2022 stating that, "The AAP does not recommend any weighted objects (e.g., weighted blankets/sleepers/swaddles) on or near a sleeping infant" (2022, AAP Publications). Parents should avoid the use of weighted items on an infant due to the potential dangers of baby not being able to reposition themselves safely due to the extra weight on the torso, or causing extra pressure on baby's chest, breathing, or heart rate. 

Ensure that the sleep sack can move freely with baby

Items that allow baby to pull in their arms inside the shoulder opening or up and out of the neck opening are not safe, as that makes the item too large and is thus designed poorly. If the sleep sack has sleeves, the sleeves should be snug enough to fit properly and conform along the baby's arms as well as not be restrictive in design. The sleeves should also be appropriately sized as to not be too long, and if they are, an option should be included where the sleeve can easily be rolled back if needed. If a sleep sack doesn't have sleeves, the arm openings should still be adequately sized to ensure that baby cannot pull their arm inside while sleeping. 

Ensure that the sleep sack/sleep walker/sleep suit is not restrictive in design and allows full freedom of movement 

Items that keep or encourage babies to stay in a certain position are not safe for sleep—full stop. This is particularly an issue after your baby can roll over. Any product that claims to help prevent baby from rolling over is not safe for sleep. Whether it's a standard sleep sack or one with sleeves, a sleep sack should always allow baby complete and full range of motion without any restriction. If your baby is a roller, she should have the freedom to safely and easily roll over in a sleep sack as simply she is able to while playing during the day. Your wearable blanket that you choose for your baby should not restrict any movement. As a side note, swaddling does keep babies in the supine position, but it is only meant to be used until a baby is showing signs of rolling over, which might happen as soon as 4-8 weeks, or as late as 4-7 months. As soon as that occurs, arms must be kept outside the swaddle, and the transition out of the swaddle must begin. Fear not, we are here to help!

To recap, are infant sleep sacks (with sleeves) safe? Yes, they can be, as long as the following conditions are met:

• Ensure that the sleep sack allows for the ability to regulate temperature

• Ensure that the sleep sack is form-fitting

• Ensure that the the sleep sack isn't too large or long

• Ensure that the sleep sack isn't weighted

• Ensure that the sleep sack can move freely with baby

• Ensure that the sleep sack/sleep walker/sleep suit is not restrictive in design and allows full freedom of movement  

Lastly, as with any baby product, if you are unsure about safety or just want to get an expert opinion on the item, run it by your baby's pediatrician at your next appointment! Consulting with your baby's care provider can be a great way to set your mind at ease and make the best decision for your sweet little one.