Basics Sleep

Sleep Sack vs Swaddle – What Is Best For My Baby?

We all need a good night’s rest, and if your baby sleeps well you’re more likely to get some well earnt rest too.

When it comes to dressing you baby for bed there are two main options to keep them safe and warm: sleep sacks and swaddle blankets.

The number one consideration when choosing between a sleep sack and a swaddle blanket is your baby’s age.

While sleep sacks are safe for babies of all ages (including newborns), swaddle blankets are not suitable for babies who can roll over.

But which one should you go for?

Is one safer than the other?

Let’s find out.

Sleep Sack vs Swaddle – What Is Best For My Baby?

The first thing to keep in mind is your baby’s age.

Sleep sacks are more versatile, because they are safe for babies of all ages, including newborns.

So if you start using a sleep sack on your newborn, there will be no need to transition to anything else for at least a couple of years.

In contrast, swaddle blankets are not suitable for babies who can roll over, because this could lead to suffocation (more on this later).

So if you use decide to swaddle your newborn, you will need to transition to a sleep sack a few months down the line.

Sleep sacks and swaddle bags can be used in both summer and winter, depending on the TOG rating.

But there are other key differences between the two, so let’s take a look at both in more detail.


Why Use A Swaddle?

Swaddling is a way of wrapping a baby in a blanket so that their limbs are secure and can’t wriggle out.

The idea behind swaddling a baby is to replicate the feeling of being in their mother’s womb.

According to many pediatricians, swaddling can help a baby feel calm and can promote better sleep (without the need to be held in your arms).


Because newborns have an automatic startle (or Moro) reflex, which occurs in response to not having cushioning around them, which is something they had in the womb.

woman holding baby beside man smiling

A major benefit of a swaddle is that it keeps this startle reflex in check, thereby preventing your baby from flailing their arms and legs (which could wake them up).

See Also: Why Do Babies Sleep With Their Arms Up? 5 Common Reasons

But do keep in mind that all babies are different, so your little one may not like the feeling of being swaddled.

Does Swaddling Have An Age Limit?

Yes, you should only swaddle a newborn baby who cannot roll over yet.

Once a baby can roll over, there is a risk they could end up face-down in their swaddle.

With their arms tightly wrapped, the baby would not be able to move out of that position and could therefore suffocate.

In practice this means that when your baby is around 3 or 4 months and can start to roll over, you should not dress them for sleep in a swaddle.

But for a newborn baby that cannot roll, a swaddle is a great option.

Sleep sacks

What Is A Sleep Sack?

A sleep sack (also know as a sleep bag or wearable blanket) is a wearable blanket designed to keep your baby a comfortable temperature during sleep.

These garments keep your baby’s torso, legs and feet within the sack, even if your baby moves around their crib.

They are normally made from cotton and are safest when sleeveless (more on this below).

Sleep sacks have zippers and snaps to make it easy to get your baby dressed for bed, and for making diaper changes as easy as possible.

One of the major benefits of a sleep sack is that it eliminates the need for loose blankets, which pose a suffocation risk.

Are Sleep Sacks Safe For Newborns?

Sleep sacks are safe for newborn babies, provided the fit is correct.

To ensure you have the right fit, make sure the fabric of the sleep sack cannot go over your baby’s head, and opt for a sleeveless sack.

Most manufacturers make it easy to find the right fit by providing sizing information based on your baby’s age, weight and height.

Are Sleep Sacks Safe For Babies Who Can Roll Over?

Yes, sleep sacks are safe for both newborn babies as well as babies who can roll over.

The correct size will allow your baby to move freely without the risk of being trapped or having fabric cover their head.

Again, provided their arms and hips are free to move, there are no issues with using sleep sacks for babies who can roll over.

Are Weighted Sleep Sacks Safe?

There is conflicting advice about the safety of weighted sleep sacks.

The advantage of these is they may help a baby sleep better because it recreates the feeling of being “held” and feeling secure.

However, many experts believe weighted sacks may inhibit breathing, especially in younger babies.

If you do use a weighted sleep sack, it is recommended to never use one that weighs more than 10% of your baby’s body weight.

But for extra piece of mind you should check with you pediatrician before using a weighted sack.

woman holding baby up

How Long Do Babies Use Sleep Sacks?

There is no one size fits all as to when your baby should stop using a sleep sack.

Your baby’s size (height and weight) are more important than their age when deciding to transition from a sack to a blanket.

As a general rule, most babies can use sacks until around the age of 2.

However, some babies continue to use sacks for longer.

If your baby moves around a lot in their sleep then you may want to stay with a sleep sack for longer.

This is because unlike a blanket, a sack will stay in place and keep your baby warm however much they move in their crib.

Sleep Sacks vs Swaddles – Which Is Safer?

You may be wondering whether there’s a difference in safety between sleep sacks and swaddles?

The answer is that both are safe, as long as you use the right one for your baby’s age and development.

If you decide to swaddle, you should always ensure the swaddle is tight enough to not come loose and fall off.

For a newborn, a loose swaddle in their crib could potentially be fatal as it may cause suffocation.

If you decide to use a sleep sack, opt for a sleeveless version, always ensure the material cannot go over your baby’s head, and select the correct TOG rating for the temperature in your baby’s room.

Must Read: The Ultimate Guide To Baby & Toddler Sleep

Tori is mama to 3 year old Isabella and co-founder of Rockinbaby. She has a BSc in Psychology, is a certified yoga teacher and is a working mom. In her free time Tori loves cooking delicious foods and baked treats, entertaining and working out. Learn more about Tori here.

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