Swaddle vs. Sleep Sack: Which Is Right For Your Little One?

It’s hard to overstate just how important sleep is for babies. Not only does the time they doze equate to precious hours where you can sleep—or catch up on your lengthy to-do list—but it’s key for your child’s cognitive development and physical growth. With that in mind, you’ll surely want to optimize their sleep in any which way you can, from using the right noise machine to getting nursery lighting just right. Also important is how your little one stays warm and cozy while they snooze. Which leads us to the question we’re here to dig into: Should you use a sleep sack or a swaddle?

This is a topic worth discussing because how you set your baby or toddler up for bed can impact how well they sleep. Beyond that, it could be the difference in their safety. Ahead, we’ll explain key differences in sleep sacks vs. swaddles and offer a refresher on safe sleep.

Safe Sleep Recommendations

Because safe sleep practices will be mentioned throughout this article, it’s worth reviewing them before we focus on swaddles and sleep sacks. Here’s an overview of current recommendations from the American Academy of Pediatrics (AAP).

• Put infants to bed on their backs, at night and for all naps.
• Don’t bed share with your baby.
• Use a crib or bassinet with a firm mattress and a fitted sheet.
• Don’t leave babies to sleep on couches, chairs, car seats, or baby swings.
• Remove all loose objects from sleep areas, including blankets, pillows, and toys.

What Are Swaddles?

When you picture a precious, pink-cheeked newborn, there’s a solid chance you see a baby wrapped in a swaddle—even if you aren’t 100% sure what one is. To clear that up, a swaddle refers to a thin blanket that’s used to wrap a baby and keep them secure. The swaddle wraps around their entire body, keeping their arms and legs close. When they’re all wrapped up, just their head is out, and they can’t move freely. (Don’t worry, most newborns find the restrictive movements to be comforting, reminding them of their time in the womb.) This can help keep your little one safe and sound. In fact, it’s a practice parents and caretakers have used since ancient times to help soothe newborns.

Swaddles are made out of small pieces of lightweight fabrics like cotton and muslin to help prevent overheating. (The lightweight material also makes them particularly convenient as you can easily roll one up and stow it in your diaper bag.) Some feature fasteners to make wrapping your baby easier.

As you continue reading, keep in mind that while a “swaddle” is a type of baby blanket, the term can also be used as a verb. When used this way, it means the act of wrapping (i.e., swaddling) your baby in a blanket.

How to swaddle a baby

1. Lay the swaddle out flat and fold one corner down.

2. Place your baby on the blanket face-up with their head just above the fold.

3. Taking one corner, wrap the blanket over your baby’s body. Tuck it underneath them.

4. Lift the bottom corner and fold the blanket over your baby’s feet.

5. Pick up the final corner and bring it across your baby, tucking it into place.

When you finish swaddling, and your kiddo looks like an adorable baby burrito, make sure the blanket is not too tight. Their hips should be able to move, and you should be able to fit at least two fingers between your baby’s chest and the swaddle.

You should also look for signs of overheating. These can include sweating, damp hair, flushed cheeks, heat rash, and rapid breathing.

What Are Sleep Sacks?

While people have swaddled babies since 4000 BC, sleep sacks were first popularized in the early 2000s. In recent years, interest has steadily grown. Google searches for “sleep sacks” are on an incline, and there are millions of results for “what is a sleep sack.” The answer? Sleep sacks are warm, wearable blankets for babies and toddlers. They fit fairly loosely so that your kiddo can move their legs about and stretch as they please. Typically, they’re sleeveless, which contributes to your baby’s freedom to move.

Sleep sacks come in different types of fabrics (not to mention countless colors and patterns). You can use ones made of different materials based on the season and how much warmth they need to provide.

How to use a sleep sack

Putting your baby in a sleep sack requires less practice than using a swaddle. For the most part, it’s even easier than putting on pajamas. Simply open up the sleep sack, place your baby inside, gently pull their arms through the openings, and zipper or snap it closed.

What’s key is to make sure the sleep sack fits properly. It shouldn’t be too tight or too big. If the fabric goes over their head, the sleep sack is too large. We recommend checking manufacturer sizing guidelines to find a good fit.

What’s the Difference Between Sleep Sacks vs. Swaddles?

Swaddles and sleep sacks are similar in that they are used for warmth and comfort and serve as alternatives to loose sheets and blankets (both things that can pose a safety risk). However, there are a couple of notable differences.

Comfort

Like we said, both sleep sacks and swaddles offer comfort. Some parents may find that newborns prefer being swaddled since the idea is to mimic being in the womb.

Hip Health

Swaddles and sleep sacks can both be safe if used correctly.what But with swaddles, there can be an added risk of hip dislocation or dysplasia. This can happen if the baby is swaddled incorrectly, with their legs wrapped too tightly.

Daycare

Some childcare centers have policies against swaddling. This is something to keep in mind if you want to keep sleep practices consistent at home and at daycare.

Age

Arguably, the biggest difference between swaddles and sleep sacks is the ages at which they can be used. Swaddles are safe to use for a shorter period of time, while sleep slacks can have more longevity. Next, we’ll break this down further.

When To Use a Sleep Sack or Swaddle

Swaddles: You can swaddle your newborn bundle of joy at the hospital; a nurse may even do it for you. This may help your little one feel snug and secure. However, this can’t be used as a source of comfort forever. Once your baby can roll over, swaddling is no longer safe. If your baby rolls onto their stomach while swaddled, they may not be able to roll back since their arms will be pinned to their sides. This can increase the risk of suffocation and SIDS.

For many babies, rolling over is a four to six-month milestone, but some start trying to roll over as early as two months old. Because every baby is different, it’s important to monitor your kids and look for any signs that they’re becoming more mobile. As soon as they start to roll (or attempt to roll), it’s time to stop swaddling.

Sleep sacks: Like swaddles, sleep sacks are safe for newborns. The difference is, sleep sacks can be used even after babies begin to roll. This is because they don’t pose the same suffocation risks as swaddles. If the sleep sack doesn’t compress the arms, chest, or body—allowing your baby to move freely—it can be used as long as it fits. (Note: There are some sleep sack-swaddle hybrid products that do compress the body like a swaddle. These are unsafe after your baby starts to roll.)

Parents may find that sleep sacks continue to have benefits well into toddlerdom. For instance, if your little one is an escape artist in the making, a sleep sack may help keep them in their crib overnight. Once your toddler outgrows sleep sacks, they’re likely ready to use a regular blanket. (For older kids, make sure to read our Toddler & Child Sleep Guide.)

What age do you transition from swaddle to sleep sack?

When it comes to deciding between a swaddle or sleep sack for a newborn, it’s largely about preference. As we said, both can be safe options after your baby is first born. If you start with a swaddle, you can transition to using a sleep sack once your baby starts to roll. The exact age will depend on your baby’s development, as some hit this milestone months earlier than others.

If you start with a sleep sack, you won’t have to make the same transition, but you may need to upgrade the sleep sack over time as your baby grows.

Should You Swaddle in a Sleep Sack?

As an adult, you might love to sleep under multiple layers and feel nice and toasty. But babies can overheat easily and don’t need loads of layers. You can pick either a swaddle or sleep sack to keep them warm, rather than both.

Next, learn about how white noise could be the thing missing from your baby’s bedtime routine.