Half of all parents are using a hand-me-down mattress for their baby, but Which? tests have found that cot mattresses can lose more than 25% of their firmness in just a few years of use.
This means that using an older second-hand or hand-me-down mattress for a new baby might not be firm enough to give the sleeping surface a newborn needs.
When we surveyed 2,000 parents in February 2017 about cot mattresses, 12% of parents admitted to using a second-hand cot mattress, while 42% said they used the same cot mattress for more than one child.
Find out which cot mattresses keep their firmness over time and which go softer and saggy in our cot mattress reviews.
Why should you replace your baby’s cot mattress?
Advice from the Lullaby Trust, the baby sleep and SIDS prevention charity, states that where possible, parents should have a new mattress for each baby.
Kate Holmes, support and information manager at the Lullaby Trust, explains why:
‘At The Lullaby Trust, we always advise parents to sleep their baby on a new mattress which is firm, flat, waterproof and in a good condition.
‘We give this advice as there is some evidence suggesting a small increase in the risk of Sudden Infant Death Syndrome (SIDS) occurring when baby is slept on a second-hand mattress from outside of the family.
‘However, we understand that not all families are able to buy a new mattress, so if you choose to sleep your baby on a second-hand mattress, ensure that it was completely protected by a waterproof cover by its previous owner, and that it is still firm and flat. Doing this while following all of our other safer sleep advice will help to reduce the risk of SIDS.’
How Which? tests cot mattresses
Each cot mattress we test is put through the equivalent of roughly two to three years of use. We roll a barrel-shaped weight over the cot mattress several thousand times. We then record any changes to the mattress, including the change in height and firmness of the mattress.
If you do choose to use your own mattress for a second (or more) time, ensure it is still firm and flat with no tears or holes, and isn’t sagging in places. You should thoroughly clean the waterproof layer and ensure the mattress is clean and dry before making it up with fresh bed clothes.
To find out how well different mattresses support your baby, their durability and how easy they are to clean, and which ones came out top in testing, read our Best Buy cot mattress reviews.