When we think about babies, “firm” or “hard” are definitely not the first adjectives that come to mind. We tend to think that it’s a good thing to enclose our little ones into safe spaces that look pretty much like bubbles of feather-soft blankets, pillows, fluffy onesies, plush toys… All things warm, cozy and squishy.

Before reading this article, the first idea for your baby’s new bed was probably not to buy a firm crib mattress but to get something like a giant sponge that your bubble of joy can sink into and dream about all the diapers they will fill once they wake up.

While all of this may be adorable to look at and well applicable to how you should handle the surroundings of your newborn in general, neither bedding nor a crib mattress should not follow this pattern.

It is important that a crib mattress has a certain firmness. The Consumer Product Safety Commission (CPSC) in the US recommends that baby mattresses should be firm and flat. The reason for this is that a soft mattress and bedding, as surprising as it may be, will do more bad than good in the long run. There are two main reasons for this: one is life-changing, and one might even be life-threatening.

Suffocation risk

This is the life-threatening factor. While you might want to think that your baby is safer when placed in a mattress that it can sink into and that will limit its movement – this is exactly the reason as to why a soft mattress can be EXTREMELY dangerous.

Despite the fact that your little one is somewhat restricted in motion, it will still tend to move. Babies are very curious from the day they are born. As time goes on, they will have more and more will to reach for objects around them and try and come closer to them. This is a natural pattern through which they learn how to interact with their surroundings, and ultimately also the way they learn how to properly use and strengthen their little bodies as they grow.

Even when they still haven’t learned how to stand, kneel or crawl – your baby will instinctively attempt to get around on its own by kicking with their little arms and legs; which results in tossing and turning. If your baby happens to be on a soft mattress, they can easily face-flop into the mattress and sink in, restricting their airflow.

Babies move more easily on a firm crib mattress, but that doesn’t necessarily mean that there’s a bigger chance to hurt themselves this way. On the contrary – if you find a right-fitting mattress for your crib and secure the rest of the construction, then the restless movements can only help your baby grow faster and stronger.

The biggest risk of Sudden Infant Death Syndrome (SIDS) is actually suffocation, and most often – the suffocation is a direct result of the baby moving around an improperly equipped crib.

It’s not just that the mattress needs to be firm for SIDS to be avoided – it’s that you shouldn’t use thick soft bedding, leave your baby unsupervised with loosely wrapped large fluffy blankets, or leave soft pillows laying around. The American Academy of Pediatrics reviewed a study of nearly 1800 SIDS cases and confirmed that, out of those related to suffocation, a mind-bogging 69% were a direct result of soft bedding, and 12% of the baby getting wedged between objects placed in the crib – all misfortunate but avoidable tragedies.

Skeletal support

firm crib mattress
Photo by Filip Mroz

The biggest long-term benefit of a firm crib mattress for your baby is skeletal support.

Let’s review an ideal scenario in which your baby will always sleep constantly supervised and the risk of SIDS is close to zero. In this case, is a firm crib mattress still better than a soft crib mattress? The answer is yes, yes it is.

Even if we didn’t look at the suffocation risks, your baby still wouldn’t flourish health-wise on a soft mattress in comparison to a hard mattress as it doesn’t provide as much skeletal support.

Babies are born with roughly 300 soft bones, which slowly fuse together to form the 206 bones of the adult human body. Most of this process happens within the first couple of months after birth. As your baby spends the majority of their time in this period sleeping, you want to make sure that you enable proper skeletal growth and development, and you can best do this by providing your little one with a good mattress.

If your baby was to sleep on a soft surface most of their time, they would essentially continue sleeping in a slight fetal position, which means that the bones of their back and limbs would fuse together slightly curvy. In the long run, this means that your child could have very painful back and joint problems that will take a lot of work to be corrected. While this isn’t necessarily life-threatening, it can certainly be life-altering.

What’s a good firm crib mattress?

If you’re wondering – then why am I buying a mattress in the first place? Why don’t I just let my baby sleep on the table or floor? The simple answer is that you are looking for a FIRM crib mattress, not a HARD one. Your mattress should be firm enough so that your baby can sleep with a straight back without sinking into it, but still soft and flexible enough so that they can’t hurt themselves. You can check some of our reviews to have some idea before you go to the store. There are a couple of easy tricks you can follow;

Look for holes and indentations

The first thing you need to check on the mattress that you want to buy is how flat it is. Good mattresses don’t have valleys and peaks, all of its points are on the same level. Check for any holes and indentations, as these can increase the risk of your baby getting stuck in them. An uneven surface can also possibly make the mattress oddly-fitting in your crib despite the matching size on the label.

Firmness press test

Secondly, you want to perform a firmness press test to see how indentation resistant the mattress actually is. To do this, simply press the mattress with your finger and quickly remove your hand. The mattress should bend with pressure, but snap right back upon releasing. If it doesn’t, its either a case of damaged or second-hand goods. Make sure to do the press test on all areas of the mattress to confirm consistency.

Either way, you can consult our other guide to get to know other things you need to pay attention before buy any mattress.

Of course, you should also keep in mind that softness when it comes to baby cribs is a temporary comfort, but long-term worry. Never leave your baby unsupervised with soft bedding, and prioritize buying a top-quality firm crib mattress for the sake of their well-being.