Cot Mattress How To Choose

Home   /   Cot Mattress How To Choose

Cot mattress safety

By Alison Potter

Give your baby and toddler the best and safest sleeping space with our top cot mattress tips.

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You’ll instantly be able to compare our test scores, so you can make sure you don’t get stuck with a Don’t Buy.

A crucial part of safe sleeping is choosing the best cot mattress. The Lullaby Trust, the UK’s foremost organisation on baby safe sleeping, recommends that the safest place for your baby to sleep is on their own sleep surface, in the same room as you, for at least the first six months. Read on to see what makes a safe cot mattress.

  • Make sure you choose the right size of cot mattress. The mattress should fit the cot with no gaps down the side that are more than 3cm.
  • Make sure the mattress is firm and flat, and protected by a waterproof cover (sometimes called a mattress protector).
  • Avoid second-hand mattresses where possible. Check any mattress you use conforms to current safety requirements.
  • Mattresses should carry the BSI number BS 1877-10:2011+A1:2012. It’s preferable if they also carry BS 7177:1996 and BS EN 16890:2017. See below for more information about these standards and what they mean.

Safety standards for cot mattresses

Cot mattresses that comply with the current British Standards requirements give you confidence that what you’re buying for your baby is safe, and we would always encourage you to check whether your products are marked with a BS number.

With cot mattresses it’s slightly more complicated, as there are a number of BS numbers to look out for. BS 1877-10:2011+A1:2012 is an older mandatory standard that specifies the kinds of materials, construction and dimensions required when manufacturing mattresses, while BS 7177:1996 guarantees it has passed flammability standards.

There’s also a much newer cot mattress standard called BS EN 16890:2017, which was approved in September 2017. Although it’s currently a voluntary standard, it includes a number of requirements designed to test the performance and safety of cot mattresses.

This involves checking that no part of the mattress, for example the zip, can detach and become a choking hazard. There is also a test to check the firmness of the top of the mattress, so if your baby accidentally rolls onto their front, their face won’t sink into the mattress and potentially suffocate them. In addition it checks whether the removable cover shrinks after washing, in case it compresses the mattress and causes a gap between the mattress and the bed frame where your child could trap a limb.

The BS EN 16890:2017 standard encompasses a wider set of tests and risks than the current mandatory standard and we feel it goes further in regards to child safety. We test to this standard because we believe it goes further to ensure a safe sleeping environment for babies and young children.

Which cot mattress is best?

We test the firmness, body support and durability of each cot mattress we review, so we can recommend the best to you. If a mattress isn’t firm enough to aid safe sleep and isn’t sufficiently supportive then it becomes a Don’t Buy cot mattress.

Find out which mattress came out top in all these tests and the others we carry out (such as how well each mattress copes with leaks and baby sick) in our round up of best cot mattresses.

New cot mattress for second baby? Buying second-hand?

Maybe you are having baby number two and are thinking about using your first baby’s cot mattress. Or maybe you are considering buying and using a second-hand mattress.

The Lullaby Trust recommends you buy a new cot mattress for your baby, where possible. That’s because it says there is some research that found an increased chance of sudden infant death syndrome (SIDS) when using a second-hand mattress, although the link is not yet proven.

Our cot mattress testing has found that often mattresses lose firmness after a couple years of use. This means that a mattress used second-hand for a new baby might not be firm enough to give the safest sleeping surface a young baby needs.

If you have a second-hand mattress, whether it’s a mattress you’ve used for one of your other children or one that has been given to you, check the following:

  • That the cot mattress is in good condition; that it’s flat, firm, not soft, fits the cot without any gaps and doesn’t sag.
  • It has been cleaned and dried thoroughly.
  • Check that it was previously used with a waterproof cover.
  • Make sure you use it with a waterproof cover.
  • Check it’s free from cracks or tears or holes.

What is SIDS/sudden infant death syndrome?

Sudden Infant Death syndrome (or SIDS) is a term used to classify any sudden and unexpected death of a baby 12 months of age or younger. Sometimes referred to as ‘cot death’, it still isn’t known for sure what causes SIDS, but there are steps that parents can take to reduce the risk of it happening. Parents are urged to follow safer sleep advice when putting their baby into his or her cot. This includes:

  • Keep your baby’s cot in your room with you for the first six months.
  • You should always place your baby on his or her back to sleep, not front or side (unless your doctor advises otherwise). If your baby rolls onto his or her tummy you should turn them onto their back again. Your baby should be put to down to sleep in this position until he or she is able to roll from back to front and back again.
  • Place your baby with feet to the foot of the cot, so he or she can’t wriggle down under the covers.
  • Don’t worry if he or she wriggles up and gets uncovered.
  • It can be dangerous if your baby’s head gets covered when he or she sleeps. To avoid this, tuck in the bedclothes firmly around your child and no higher than his or her shoulders.
  • Never use a pillow, quilt or duvet if your baby is under one year old. Instead, use cotton sheets or lightweight blankets.
  • Alternatively, you can use a baby sleeping bag instead of bedding.
  • The recommended room temperature for a baby to sleep in is 16-20ºC (61-68ºF) – use a room thermometer to check the temperature before putting your baby to bed.
  • To check whether your baby is too hot, look for sweating or feel the back of your baby’s neck or his or her tummy, not hands or feet.

Overheating while sleeping and SIDS

It is very important that your baby does not overheat while sleeping as the chance of SIDS is higher in babies who get too hot while sleeping.

Many cot mattress manufacturers make claims about their mattresses having extra features that provide a cooler sleeping surface for your baby, such as special construction or fabric.

It’s important to know that your cot mattress won’t single handedly be able to keep your baby from overheating, so make sure you follow the temperature advice above.

Also be careful of letting marketing claims on mattresses sway your buying decision. One of the things we test cot mattresses for is insulation and we classify each mattress in terms of the level of insulation it provides.

Compare ourcot mattress reviewsto see the differences.

Buying a mattress

There are many types of cot mattress available. You can choose between foam spring interiors, natural fibres, special anti-allergy fillings, or a combination of any of the above.

You may find it difficult to decide which is the best and safest mattress for your baby. But The Lullaby Trust states that it doesn’t matter what kind of mattress you use, as long as it:

  • is firm not soft
  • fits the cot snugly without any gaps
  • doesn’t sag
  • doesn’t have signs of wear and tear

Any mattress you choose should conform to BS 1877-10: 1997. It should also be at least 8cm to 10cm deep to support your baby while she sleeps.

If the mattress you choose has a fabric cover, vacuum it regularly to keep dust mites at bay.

Unless you know the history of a second-hand mattress, buy a new one. This will give you peace of mind.

Foam mattresses

Foam mattresses are generally the cheapest. They are designed to provide the right support and maintain your baby’s natural posture. They often have a wipe-clean PVC cover or removable, breathable covers on one or both sides. They may also have ventilation holes to help keep your baby cool, but these aren’t necessary.

Pros

  • lightweight
  • provide good support
  • good value for money
  • generally easy to keep clean

Coil spring mattresses

These traditional mattresses have a coiled spring interior with layers of felt and foam padding. They often have a cotton cover on one side and PVC, or other wipe-clean material, on the other side.

A spring inner core will support your baby. These mattresses also tend to hold their shape well. If you choose a cot bed, you may prefer a coil spring mattress as they tend to be longer lasting than foam.

The space within the spring lattice allows for increased airflow through the mattress. This helps to regulate a child’s body temperature and to keep the mattress fresh.

Pros

  • They are a traditional, popular choice with many parents.
  • In hot weather, you can lay your baby on the cotton cover side to prevent her becoming clammy.

Cons

  • More expensive than a foam mattress.
  • The cotton side may be preferred for comfort, but can be more difficult to keep clean, unless your mattress has a removable panel.

Pocketed spring mattresses

These mattresses are very similar to coil spring mattresses, but each spring is in its own pocket to provide improved support for longer.

Pros

  • excellent support
  • extremely hard-wearing

Cons

  • Expensive.
  • Probably not cost-effective, unless you have a cot bed that your baby will sleep in for several years, or the mattress will be used for more than one child.

Dual Core™ mattresses

The Dual Core™ cot mattress is a patented design that incorporates two cores in one. It aims to meet the needs of your child from when they are first born to when they start school.

For your newborn baby, it has a coir and orthopedic foam interior, which provides a flat and firm sleeping surface. As your baby grows into a toddler and preschooler, the second core incorporates micro-pocketed springs to conform to your child’s changing weight and shape.

Pros

  • excellent support throughout your baby’s early years
  • extremely hard-wearing
  • holds its shape well

Cons

  • expensive

Natural fibre mattressess

Natural fibre mattresses have a core of coconut fibre with other layers of different materials. The fibres are coated in latex for strength and protection, and the natural fibre filling helps air to circulate through the mattress. These mattresses are available with a soft cotton or wipe-clean covering.

Pros

  • Good choice if you are concerned about your baby sleeping on synthetic material, or you are concerned about introducing unnecessary chemicals or synthetics into your home.
  • One of the firmest types, so the mattress is long-lasting, and holds its shape well. This could be a sensible choice if you want a mattress that will last for more than one child.

Cons

  • More expensive than foam or most spring interior mattresses.
  • Less widely available than other types of mattress.

Hypoallergenic mattresses

If allergies or asthma are a concern in your family, you may want to consider a hypoallergenic mattress for your baby. These come with a quilted top layer that can be easily detached and washed at 60 degrees C to kill the dust mites that may cause allergies. Allergy UK has a list of approved mattress covers and bedding.

Pros

  • Good choice if your baby has allergies or asthma.
  • Easy to keep clean.

Cons

  • May be more expensive than other kinds of mattress.
  • For most babies, this may be a luxury buy.

We’ve used shopping tag symbols to show you where we’ve placed an Amazon shopping link. Purchasing through these links may earn BabyCentre a small Amazon commission. Thanks for supporting us!

Our tips help you find a safe mattress for your baby.

Did you know you can legally buy a cot mattress that doesn’t meet product safety standards? Just because it’s on retail shelves doesn’t necessarily mean it’s safe. A sleeping surface that’s too soft increases the risk of fatal sleeping accidents if a baby rolls over face-first and their breathing becomes obstructed due to their nose pushing against any cushioning or undulating surfaces in the mattress. But how do you know which mattresses are safe?

Looking for cot mattresses?

We’ve tested to find you the best.

How firm is firm?

Parents are advised by safety experts to always choose a ‘firm’ mattress to minimise the risk of sudden unexpected death in infancy (SUDI). But until very recently there was no agreed definition of ‘firmness’.

The good news is that there is now a standard test method for firmness, AS/NZS 8811.1:2013 Method 1: Sleep Surfaces – Test for firmness. However, it’s not mandatory for cot mattress makers (or makers of any other infant sleep surface, such as a bassinet) to meet this standard, and we still aren’t seeing many mattresses claim compliance. This means consumers don’t know whether a cot mattress is safe.

Two milk cartons placed on top of a stack of CDs is a useful way to test for firmness. This mattress is safe because the lower carton overhang does not come into contact with the mattress surface.

How to test cot mattress firmness at home

  • Two unopened 1L milk or juice cartons with square bottoms (not rectangular bottoms)
  • A marker
  • A ruler
  • A stack of 12 DVDs or CDs (not in their cases), protectively and tightly wrapped in cling film

Wrapping a stack of DVDs or CDs in some cling film.

  1. Mark one of the milk cartons with a line 40mm parallel from the base. Mark all four sides this way so they form a ring around the carton.
  2. Place the tightly wrapped discs near the softest part of the sleep surface. Look for a ‘worst case scenario’, such as a fold or peak on the surface where a baby’s nose could be positioned.
  3. Lay the marked milk carton sideways on the stack of discs so that it is centred, and have the marked line match up with the edge of the disc so you get a 40mm overhang. Make sure the overhang sits over the soft part of the sleep surface.
  4. Lay the second carton sideways and stack it onto the first, making the stack as level as possible – this usually means selecting an off-centre position.
  5. See whether the overhang touches the soft part of the sleep surface. If it does then the sleep surface is too soft to be safe.
  6. Test a few locations on the mattress, especially anywhere where the child’s head might rest. A mattress should be firm enough in every location on the sleeping surface.

For a practical demonstration, see the video.

An informal method for determining cot mattress firmness at home.

Check cot mattress dimensions at home

  • Check that the mattress fits snugly in the cot and that it meets the cot manufacturer’s recommended dimensions.
  • There must never be more than a 4cm gap between the edge of the mattress and the adjacent cot side when the mattress is pushed to the opposite side. Gaps at the sides are a suffocation risk, just as firmness is.
  • If a mattress fits too tightly, on the other hand, sections of the mattress could deform and bunch up along the cot edge, making it easier for a child to climb out of the cot. It could also cause the dropside to not move freely, if there is one.
  • The thickness of the cot mattress can also be the difference between a cot failing the mandatory standard for cot depth. The distance from the top of the mattress to the top of the lowest side when the dropside is closed should be at least 50cm when the base is in the lowest position, and at least 30cm in the upper position.

What kind of material is best? And what about comfort?

You’ll often find cot mattresses promising "comfort" or "support" for your baby. A baby is not built like an adult, and a firm mattress, not a cushioned one, is safest for your baby. Our tests show that cot mattresses which are flat and do not have undulating or quilted features are less likely to fail our firmness test.

As for mattress construction, you’ll find a huge variety including foam, latex and inner-spring. All of these sorts of mattresses are capable of passing the firmness test, so we can’t recommend one type over another, but an inexpensive and very basic mattress is just as likely to be as good as any other.

Are vacuum-packed cot mattresses safe?

Some cot mattresses are shipped in boxes where they’ve been vacuum packed and rolled up. In these cases, you will need to allow several days at least for the mattress to fully expand. In our latest round of testing, some cot mattresses remained slightly bent even after several weeks, thus failing the firmness test.

Are second-hand mattresses safe?

New cot mattresses are best. However, if you’re getting one second-hand it’s important to know that any previously-used mattress should be firm enough, clean and show no signs of dampness or mould. It’s also vital that it fits well in the cot. Red Nose provides more information on using second-hand mattresses.

Safe sleeping tips

More tips on keeping your cot safe are on the Red Nose website. The main things to remember:

  • Choose a standards-compliant cot; see our review for recommendations.
  • Never wrap your mattress in plastic or any other unbreathable material.
  • Soft toys and bumpers could pose a suffocation risk and should never be placed in the cot.
  • Always place baby to sleep on his or her back, with feet at the base of the cot.
  • Do not use doonas/quilts, lambswool, thick blankets or pillows in the cot.
  • Buy a firm, safe mattress.
  • Keep baby’s head uncovered and away from blankets, which should be tucked in tightly. Alternatively, use a safe sleeping bag.

How to check cot mattress dimensions at home

  • Check that the mattress fits snugly in the cot and that it meets the cot manufacturer’s recommended dimensions.
  • There must never be more than a 4cm gap between the edge of the mattress and the adjacent cot side when the mattress is pushed to the opposite side. Gaps at the sides are a suffocation risk, just as firmness is.
  • If a mattress fits too tightly, on the other hand, sections of the mattress could deform and bunch up along the cot edge, making it easier for a child to climb out of the cot. It could also cause the dropside to not move freely, if there is one.
  • The thickness of the cot mattress can also be the difference between a cot failing the mandatory standard for cot depth. The distance from the top of the mattress to the top of the lowest side when the dropside is closed should be at least 50cm when the base is in the lowest position, and at least 30cm in the upper position.

What kind of material is best? And what about comfort?

You’ll often find cot mattresses promising "comfort" or "support" for your baby. A baby is not built like an adult, and a firm mattress, not a cushioned one, is safest for your baby. Our tests show that cot mattresses which are flat and do not have undulating or quilted features are less likely to fail our firmness test.

As for mattress construction, you’ll find a huge variety including foam, latex and inner-spring. All of these sorts of mattresses are capable of passing the firmness test, so we can’t recommend one type over another, but an inexpensive and very basic mattress is just as likely to be as good as any other.

Are vacuum-packed cot mattresses safe?

Some cot mattresses are shipped in boxes where they’ve been vacuum packed and rolled up. In these cases, you will need to allow several days at least for the mattress to fully expand. In our latest round of testing, some cot mattresses remained slightly bent even after several weeks, thus failing the firmness test.

Are second-hand mattresses safe?

New cot mattresses are best. However, if you’re getting one second-hand it’s important to know that any previously-used mattress should be firm enough, clean and show no signs of dampness or mould. It’s also vital that it fits well in the cot. Red Nose provides more information on using second-hand mattresses.

Safe sleeping tips

More tips on keeping your cot safe are on the Red Nose website. The main things to remember:

  • Choose a standards-compliant cot; see our review for recommendations.
  • Never wrap your mattress in plastic or any other unbreathable material.
  • Soft toys and bumpers could pose a suffocation risk and should never be placed in the cot.
  • Always place baby to sleep on his or her back, with feet at the base of the cot.
  • Do not use doonas/quilts, lambswool, thick blankets or pillows in the cot.
  • Buy a firm, safe mattress.
  • Keep baby’s head uncovered and away from blankets, which should be tucked in tightly. Alternatively, use a safe sleeping bag.

How to choose the best cot mattress for your baby

Preparing for a baby can be tricky. There are endless different options for even the most basic items, and cot mattresses are no exception! Here’s what you need to know about baby mattresses and how to choose the right one for your bub.

Be firm – why too soft can be dangerous

It could be a natural assumption that a nice soft mattress would be perfect for your precious baby (bed of clouds perhaps?), but that’s not actually the case. Mattresses which are too soft can in fact increase the risk of SIDS (Sudden Infant Death Syndrome). This because if a baby rolls on to their tummy, and the mattress has any soft cushioning or wave-like surface grooves, then their breathing can be obstructed.

So looking for a mattress that’s firm is very important, such as the Tikk Tokk Sweetdreams Mattress from Babies R Us. Made from pure cotton with a removable cover (handy!), it has double firmness with a ventilated inner area for airflow and overheating prevention, plus improved moisture management.

Match the size of the mattress to the cot

Don’t be tempted to use any size mattress for the cot (even if you have access to a spare one or really want to buy a particular one you’ve found). You need the mattress to meet the cot manufacturer’s dimensions, and when it does the mattress will fit snugly in the cot. This is because if you have a gap of more than 4cm between the edge of the mattress and the adjacent cot side (when the mattress is pushed to the opposite side), there is a suffocation risk again. On the flip side, if you squash a mattress that’s too small into a cot, it could bunch up – making it easier for your baby to climb out. It can also stop the drop side (if you have one) from working properly.

How to Choose the Right Cot-bed Mattress

How to Choose the Right Cot-bed Mattress for Your Baby

Cot-beds are extremely popular for new babies, because they give you longevity, allowing you to transition from a cot to a junior size bed when your child is ready with just a few simple modifications. However, as good as your cot-bed furniture is, you should make sure that you do get the rightCotbed Mattressfor your baby. Of course, one thing’s for sure, if you choose a cheap and uncomfortable mattress your baby might not get a good night’s sleep – as well as baby waking regularly, you don’t want to spend years getting up in the middle of the night trying to cajole your little one back into comfortable slumber.
Choosing the right type of cot-bed mattress will make all the difference, and with today’s spectacular high-end products there’s a multitude of great features to take on-board. Let Baby & Co take you through what you should look for.

Now, today’s mattresses should be safe and help prevent SIDS (sudden infant death syndrome). There are mainly four different types of mattress available for your baby’s cot bed. The reliable mattresses on Baby & Co range from £39.99 to £299.00 and come from reputable manufacturers, so there’s plenty of choice in price and definitely something to suit even the fussiest sleeper! So what should you be aware of when it comes to making your choice?

Generally, there are four types of cot-bed mattresses:

Foam Cot-Bed Mattress

Foam mattresses usually sit at the lower end of the price spectrum and represent a relatively economical buy. They are made out of a single layer of foam approximately 9cm thick which gives your baby a comfortable sleep. Foam mattresses also come with a waterproof cover. You can easily unzip and machine wash (usually at 40 degrees, some up to 60 degrees) so you’re able to keep yours nice and clean. Do wash regularly, to banish allergens and bacteria. TheBabyWise Foam cotbed mattressis made out of polyester mesh and PVC so it’s breathable too. This type of mattress is good value; however, if your baby’s room is generally in a warm area of your house, it might not be the best option as the foam tends to reatin heat and may make your baby too hot. Best to keep bed clothes lightweight if you decide to choose a foam mattress.

Sprung Cot-Bed Mattress

Sprung mattresses are made up of lots of coiled springs which fit together vertically inside the mattress. Some are covered with foam, others with felt and then there’s the fabric cover which may or may not have a wipe-clean area. Firmer than foam mattresses, they should provide your baby with good overall support. OurBabywise Sprung Cotbed Mattressis a deluxe style with high tensile coils that are designed to give your baby good comfort along with that support needed. This mattress also boasts a removable, quilted cover that is conveniently washable too so you can keep it nice and clean. It’s wise to choose a reputable manufacturer like BabyWise for sprung mattresses because you don’t want the coils to be felt through the surface of the mattress. We have plenty of other great sprung cotbed mattresses available too, all from premium manufacturers.

Pocket Sprung Cot-Bed Mattresses

Many people don’t realise that these mattresses are different to sprung mattresses. They are still made with springs, but each spring is enclosed in its own “pocket” of fabric, hence the name. They are generally the most comfortable and supportive types of cot-bed mattresses available and offer superior support for your baby. They also retain their shape, whereas some other mattresses tend to indent with time as your baby puts on weight. Pocket sprung cot-bed mattresses are more expensive than others but The Slumberland Classic Cotbed Mattress is very good value for money for a high quality pocket sprung cot-bed mattress and comes with a 2 year guarantee giving you peace of mind that it’s a good quality product. Its open coil mattress comes with additional anti-allergy technology and its cover is removable so it can easily be removed for washing. It also has a waterproof PVC layer for accidents! There is a luxury version in the form of the Slumberland Luxury Cotbed Mattress. It’s slightly more expensive than the classic and boasts responsive individual springs, an anti-allergy layer and a removable cover too. With a breathable temperature control layer and a PVC wipeable cover it’s a great all-round product.

Natural Fibres

At the higher end of the market, at £299, there’s the Boori Natural Pocket Sprung Mattress which is made out of natural fibres for supreme comfort. The cover is 100% cotton and it features a double-layer of 1000 baby sized pocket springs and 100% pure British Herdwick sheep padding so your child has the ultimate in comfort. These natural fibres allow air to circulate so your baby doesn’t perspire; they are also long-lasting and a good investment for a cot-bed especially if you want it to last your child for several years.

Cot bed mattresses (and indeed, all baby mattresses, cot and crib included) must meet the British safety standard BS 1877-10:1997. Needless to say, all the mattresses Baby & Co stock do comply. It’s important to check this out, especially if you’re buying from a different retailer.
As another word of advice, don’t re-use a mattress for a second or third baby. Always buy a brand new mattress along with a waterproof cover. This will help your baby stay protected against SIDS. We also recommend that you check your cot-bed’s dimensions so you know that the mattress will fit properly. If you would like some more information on making that all-important cot-bed mattress decision, don’t hesitate to contact one of the helpful Baby & Co advisors here.

Add a Comment: