Do I need a new mattress for my second baby?
Short answer: The Lullaby Trust recommends a new mattress for each baby where possible. If you reuse one, check it against their checklist: waterproof cover, no tears or sagging, a snug fit and a fire-resistant label.
Here is the detail behind that answer, taken from current UK guidance from the NHS and the Lullaby Trust.
Things to check
- Confirm the cot bed's mattress size before buying, as frames vary.
- Firm, flat, waterproof, with a snug fit.
- Choose foam, spring or fibre for your budget and how much you need to wipe or wash it.
What the guidance says
- The Lullaby Trust recommends a new mattress for each baby where possible. A second-hand one should have a 100% waterproof cover, no rips, tears or water damage, no sagging, a good fit and a fire-resistant label.
Related questions
What is a cot bed mattress?
A firm, flat mattress for a cot bed, usually 140 x 70cm, which carries on into the toddler-bed stage.
Shop at Baby Kingdom
- Obaby Eco Foam Mattress - 140 x 70cm
- Kidsaw Pocket Sprung Toddler Mattress 70 x 140cm
- Tutti Bambini Eco Fibre Deluxe Cot Bed Mattress (70 x 140 cm)
- Tutti Bambini Sprung Cot/Cot Bed Mattress
Check each product page for its exact dimensions, mattress size, age and weight limits and safety standards.
More advice
Is a cot mattress right for you? Quick quizIs a Moses basket mattress right for you? Quick quizCan I buy a second-hand cot mattress?Does my baby need a mattress topper?Guide to toddler mattresses: what to look forIs a Moses basket mattress right for you? Quick quizAll cot and baby mattresses advice →
Sources
- The Lullaby Trust: Baby mattresses and bedding (accessed 2026-10-21)
General information only, not medical advice. Always follow your product's instructions. If you are worried about your baby, contact your GP, health visitor or 111. In an emergency, call 999.