Does The Mattress Affect a Baby’s Sleep?

By Kimberly


As a new or soon-to-be parent, you want to make sure you set your child up for success, and one of the most important ways you can do so is by creating a good sleeping environment for your baby. But does the mattress affect how the baby sleeps?

A baby’s mattress can affect their sleep quality by impacting airway positioning and overall breathing, which impacts sleep. A good mattress is firm enough to support a baby’s airway so they breathe and sleep easily. A poor-quality or floppy mattress won’t support a baby’s weight or airway.

It’s difficult to recount everything you’ve ever read on the subject, so below you will find some key questions and answers in regards to your baby’s mattress, and how it affects them as they sleep.

An image of a newborn sleeping sweetly on his tummy in full-length white clothes in a mattress.

Does the Mattress Affect Baby’s Sleep?

The mattress is an absolutely vital part of creating a good sleeping environment, as it directly affects your baby’s sleep. Your mattress affects how you sleep, so you’ve probably thought long and hard about the mattress you sleep on. Babies need that same attention.

For the first year of their life, well over half of a baby’s day will be spent sleeping. As such, you are going to want to make sure that their sleeping arrangements are as comfortable and safe as they can be.

Choosing the right mattress is essential to ensure your baby is comfortable and safe while they sleep so they can develop properly. Babies and children need more sleep than adults do, as their brains are still developing, and a proper mattress and crib are fundamental in the early stages of your baby’s development.

Furthermore, a good mattress will support your baby’s airway so that they can breathe easily and sleep soundly. Small babies and young children under the age of two have what we in the health care field refer to as a “floppy” airway.

Children’s airways (from their mouth and nose down to their lungs) have to be kept in a straight line – or the kinked airway will lead to poor breathing and even worse sleep quality. Therefore, the mattress absolutely affects the baby’s sleep quality.

Mattresses that help hold your child’s airway in a straight line are firmer, child-approved mattresses. Your baby will be most comfortable on a firm mattress with a fitted sheet tucked tightly over the top of it. It is best if nothing else is kept in the crib with them.

Is it Bad For a Baby To Sleep on a Soft Mattress?

In the simplest terms, yes. It is bad for a baby to sleep on a soft mattress. There are three main reasons for this.

  1. Soft mattresses have an increased risk of kinked airways and suffocation-related SIDS deaths.
  2. Bone development requires proper movement, which is inhibited by soft mattresses.
  3. It’s easy to get stuck against the side of a crib with a soft mattress.

Soft mattresses and the risk of SIDS

The biggest reason why a baby shouldn’t sleep on a soft mattress is related to mobility and SIDS.

Babies don’t have a lot of mobility, and as such will not be able to get themselves into a different position. This could, at best, mean they are uncomfortable at night and wake up (thus likely waking you up). But in a worst-case scenario, it could lead to suffocation – especially if they roll over onto their tummies and can’t lift their head or reposition as older children and adults can.

Unfortunately, there have been cases of Sudden Infant Death Syndrome (SIDS) which have been caused by suffocation. To keep your baby safe through infancy, a soft mattress is not recommended to sleep on.

A soft mattress is fine for someone who doesn’t require their airway to be kept in a straight line to breathe (like babies do), or for someone who can reposition their head when they need to do so.

But because babies can’t do those things as easily yet, give them the time they need to learn those skills. Don’t use a soft mattress until they’re older and have gained the strength they need to be strong breathers and movers while sleeping.

This is also a reason why it is highly discouraged to bed-share with your baby. Not only do your blankets present a suffocation risk to your child if they get pulled up over their face, but your mattress was purchased with your comfort in mind, and most likely is too soft for your baby to sleep on. For the majority of us adults, if our beds are comfortable for us, they would not be safe for our babies.

Soft mattresses prevent movement, which can affect bone development

Babies are born with softer bones, some of which are made entirely of cartilage, and so they require a firm mattress to ensure proper bone development. Babies are born with around 300 bones, which fuse during childhood into the 206 bones that adults have.

It is imperative that babies sleep on a firm, flat surface, to ensure that the development and fusion of their bones are properly aligned.

Cartilage is quite malleable, so if a baby is stuck in one position in their bed, unable to move, the cartilage could fuse that way as they grow. This could disrupt proper growth, as well as cause any number of issues for your child in the future (back pain, neck pain, etc.).

Soft mattresses create spaces where babies can get stuck

The third and final main reason why it’s bad for a baby to sleep on a soft mattress is that they will typically have softer edges, which create gaps at the edge of the crib where your baby’s arms or legs can get stuck.

This isn’t the biggest danger that your baby could face, but this can be quite uncomfortable. I mean, would you want to get stuck smashed up against the crib rails because the mattress was too soft to support you so you could roll over and away from the rails? I sure wouldn’t!

This would also present a lack of mobility for your child, which, as stated above, is not optimal for sleep for your baby.

What Type of Mattress Should a Baby Sleep On?

According to the Consumer Product Safety Commission (CPSC), babies should sleep on a firm mattress that was either designed for their crib or a mattress that fits snugly within the crib, with as little space between the mattress and the crib edge as possible (source).

The mattress should stay firm when the baby is placed upon it and should either hold up when you press your hand down upon it, or snap back into place immediately upon removing your weight, as you are heavier than your baby, and will affect the mattress differently. 

Babies’ spines need a lot of support when they are young, and while they will be sleeping in their bed for the majority of the day, it is best to purchase firmer, better-supporting mattresses.

Which Mattress Should I Choose for my Child?

If buying a brand new crib set that includes a mattress, the mattress that comes with your baby’s crib is likely to be the one that is best suited for that particular crib.

If you have gotten your baby’s crib from another parent or purchased it second-hand online, it is best to purchase your own new mattress for it. Not only can this prevent the spread of any unwanted bacteria or mold, but it also ensures you are purchasing a mattress that is quality tested and up to standards.

When it comes to types of mattresses, and setting aside discussions about firmness for a second, it is best to look for one that is waterproof. Not only does this help prevent the molds and bacteria stated above, but it’s also really useful to clean if your baby throws up, or fills their diaper in the middle of the night. Or, if you went in to change a diaper in the middle of the night and didn’t secure it properly before leaving (no shaming here – we have all been there!). Clean-up is much easier when the mattress is waterproof.

If you don’t have a waterproof mattress, opt for waterproof fitted sheets for the mattress, if you can.

Secondly, there are 3 main types of mattresses on the market right now:

  1. Innerspring mattresses
  2. Foam mattresses
  3. Double-sided mattresses

Double-sided mattresses tend to be pricier. All of them have their pros and cons, but all of them are acceptable to many parents around the world.

Innerspring mattresses offer a more breathable design. Air passes through easier than it does through the foam, and is firmer when providing back support for the baby. They offer exactly as they sound like they do: many interior springs, to allow for maximum comfort, firmness, and a little bounciness.

A favorite innerspring mattress among parents is the Serta Tranquility Eco Firm Innerspring Crib and Toddler Mattress (on Amazon). It has over 400 5-star ratings on Amazon and has been voted as one of the top mattresses for children.

Foam mattresses can be much firmer than they sound. They are generally more lightweight and waterproof than innerspring mattresses, but parents should be conscious of how firm it is before purchasing.

If a foam mattress is more your style, then be sure to check that out. Here’s a great foam mattress to get you started on Amazon (click here to see prices).

Double-sided mattresses offer one firmer side a mattress, and a second, softer side, that can be used once your baby has grown up. As previously mentioned, they can be a little more expensive than the other mattresses, but they also do last longer. Just be conscious of which side you have facing up after washing.

A good option for this type of mattress is the Eco Classica III 2-Stage Baby & Toddler Mattress by Colgate Mattress (on Amazon). It has over 900 5-star reviews on Amazon and is similar in price to the other two mattresses mentioned.

Before purchasing any of these mattresses, please make sure you measure your baby’s crib. The mattress should not be able to slide around, and should only have as little space as possible in between the mattress edge and the crib on each side. Ideally, keep the space less than 20 mm (or 2 cm or about an inch). Less is definitely better in this case.

An image of a father holding head of a sleeping baby, sleeping in a bed in his safe hands.

Key Takeaway: The Mattress Does Affect a Child’s Sleep

Beyond just affecting your child’s safety, the mattress can impact your child’s sleep. In order to balance the best possible outcomes for both sleep and health, a mattress should be firm, never soft, with a tightly fitting sheet over the top.

This helps your child’s bone growth, spine support, and comfort, and reduces their risk of SIDS. Not only does it help your baby sleep, but it will help you sleep better at night, worrying about one less thing for your child.

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Learning about parenting or sleep training techniques is important to learn from various reputable sources. These are the sources used in this article and our research to be more informed as parents.

  • “Reduce the Risk of SIDS & Suffocation.”,
  • “Safe Sleep for Your Baby.” Home,
  • “SIDS – Parents and Caregivers.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 30 Sept. 2020,

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