Newborn Mattress

I got the mattress as part of the package when buying the cot. But the type I chose was the 4 inch thick foam anti-dustmite mattress. I personally feel that for a proper cot, the mattress must be at least 4 inches thick, and must be firm. My elder daughter has used the mattress for almost 4 years already, and it’s still good. No spinal issues, and the mattress was good for tummy time too.