The Lullaby Trust promotes advice on safer sleep for babies to help reduce the risk of sudden infant death syndrome (SIDS). It recommends that the safest mattress for a baby is firm, flat and protected by a waterproof cover. The mattress should also be in good condition and fit the cot properly with no gaps. I personally would therefore avoid buying anything second hand.
After doing some research, I decided to buy the Mothercare Airflow Pocket Spring Cot Bed Mattress (70x140cm). This mattress ticked a lot of boxes for me – it looks and feels comfortable, includes individual pocketed springs (so it provides good support for my baby’s back, neck and head), and it also has a breathable waterproof cover that can easily be removed and popped in the washing machine (plus it’s very quick drying).
According to Mothercare, the mattress cover contains Spacetec and COOLMAX freshFX technology, which helps to reduce over-heating and bacterial and fungal growth. This is supposed to help keep the mattress fresh and hygienic. This mattress also appears to have won lots of awards, for example, Mother and Baby Gold Award 2018 for Best Sleep Product, Mother and Baby Gold Award 2018 for Best Safety Product, and Mumsnet Rated.
Tip: The John Lewis & Partners Baby GOTS Organic Cotton Fitted Cotbed Sheet (2 pack) fit this mattress really well and feel very soft.