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11 Apr 2021

Five safety key tips to maintain and clean your baby's cot mattress

From the initial purchase to the most thorough cleaning method, our expert advice will help to keep your child's cot mattress in top shape.
Parent stroking babies head

You want to know the cot mattress you buy for your baby will provide the body support it needs.

But it's also crucial that the mattress provides a safe and suitable place to sleep, and remains hygienic, for several years.

Here are our top five expert tips for keeping your baby's cot mattress in the best condition.

Best Buy cot mattresses - discover the mattresses that impressed in our tough tests.

Woman inspecting a cot mattress

1. Start with buying a new, durable cot mattress

It's important a cot mattress remains firm so that it provides the support your baby needs for it's growing bones. By purchasing a durable cot mattress you can be confident it will provide the support your growing baby needs for many years to come.

We conduct durability tests on all cot mattresses, which replicate roughly two to three year's use. A cot mattress that gets four or five stars for durability will see very little change in height and firmness over time.

But how much will a durable cot mattress set you back and are there many out there? Below you can compare the price and durability scores of the 34 cot mattresses we've tested as of March 2021.

Durability scoreNumber of cot mattresses with this scoreAverage price

There are two reassuring takeaways from this - first that there's no significant difference in the average price between durability scores, so it will not cost you more to get a durable mattress.

Secondly, 82% of cot mattresses tested scored four or more stars. So you can be safe in the knowledge that most cot mattresses have great durability.

As well as durability, there are other important factors to consider when purchasing a new cot mattress. NHS guidance says that cot mattresses need to be firm, flat and fit the cot snugly. Doing your research and using our extensive reviews will help you to get the best cot mattress for your little one.

Cot mattress reviews - start your search with our expert reviews.

Man measuring a mattress with a tape measure

2. If you must go second-hand, check it in person before you buy

We recommend where possible buying cot mattresses new, especially when they are being used with a newborn.

This is also the view of The Lullaby Trust, as there is research that found an increased chance of SIDS when using a second-hand mattress brought in from outside of the family home, although the link is not yet proven.

If you need to buy second-hand, the risk can be reduced by making sure you know the history of the mattress and by checking it yourself before parting with cash.

If a reseller won't let you check if a product is safe for your child before you pay, then we'd advise looking elsewhere.

Use our checklist below to make sure you've covered the essentials.

Second-hand cot mattress buying tips

  • Make sure the cot mattress was previously protected by a waterproof cover - this will reduce the risk of unhealthy bacteria lurking in the mattress.
  • Test to see if it's still firm and lies flat, with no holes or tears - when you press down there should be resistance and the mattress should spring back immediately after you remove your hand.
  • Check the mattress isn't sagging in places- otherwise that part of the cot mattress won't provide enough support for your child, and if a baby ended up face down in the sagging area it could be a suffocation risk.
  • Make sure it fits the cot bed with no gaps around the edges - take a tape measure and check the length and width of the mattress at multiple places on the mattress. The standard size mattress for a UK cot bed is 140cm x 70cm, but double check the cot mattress size your cot bed needs beforehand.
  • Clean the waterproof layer and air-dry thoroughly before reusing the mattress - to make sure it's dirt and bacteria-free before your little one uses it.

Cot mattress safety - expert advice on what you need to give your baby a safe night's sleep.

Person zipping a cover onto a cot mattress

3. Invest in a waterproof cover

It may be an optional purchase, but not all cot mattresses are water resistant. If liquid soaks into the mattress core it creates the perfect environment for bacteria to grow and fester and make the mattress unhygienic. If that doesn't sound nice, imagine sleeping on it.

The Lullaby Trust recommends investing in a waterproof cover to make leaks and spills easier to clean and make your cot mattress last longer.

We test each cot mattress to see how resistant it is to moisture permeating its inner layers. We've found that some are very good at preventing this, while others allow liquids to pass through easily.

Parent using washing machine

4. Change your cot mattress cover regularly

As your baby will be sleeping between 12 and 18 hours a day in their cot bed, it's important to keep the mattress clean and germ-free.

Most parents are already doing this. In our February 2019 survey of 1,008 parents, 59% cleaned the cot mattress at least once a week, if not more regularly.

There isn't a hard and fast rule on how often you should clean a cot mattress, but it's recommended you change the cover at least once or twice a week.

As such, it's handy to have spare covers to hand. We'd recommend at least three - one for the mattress, one in the wash, and one spare in case of a middle-of-the-night accident.

As part of our lab testing we see how easy each mattress is to clean - checking how easy to is to take a mattress' removable cover on and off and checking the cover doesn't shrink after several washes as that could compress the mattress and cause an unsafe gap between the mattress and the cot bed frame.

Speaking of washing - look out for mattress covers that say they can be washed at 60°C. This will ensure the wash is hot enough to kill any germs.

Vacuuming cot mattress

5. Maintain and clean your cot mattress correctly

  • Just like an adult mattress, rotating your child's cot mattress will ensure it wears down evenly. Turning the cot mattress 180° about once a month will help avoid any sagging patches from forming.
  • Make sure spills and leaks are cleaned up as soon as you spot them. This will keep your mattress hygienic and germ-free.
  • We would avoid dry cleaning cot mattress covers due to the chemical content of some dry cleaning solutions.

How to clean your cot mattress

  1. Remove the cot mattress cover and wash it according to the manufacturer's instructions
  2. Vacuum the cot mattress, including the sides to get rid of any dust or dead skin
  3. Wipe the mattress all over with a damp cloth - check the mattresses labels to see if you can use a detergent, if not stick to just using warm water.
  4. Leave the mattress to air dry completely before putting the cover back on. This makes sure no bacteria or mould gets a chance to grow.

How to buy the best cot bed - get the perfect frame for your cot mattress