So I didn't use this for a baby, but rather my furbaby. This makes by far the BEST dog bed if you have a large breed dog. I have a 90lb German Shepherd and I used this with a fitted crib mattress cover and she loves it!
Not only do you get a 5" thick foam mattress that is the size of a crib, but it also comes with a waterproof liner (bonus for dogs that are accident prone) and a mattress cover and a flame resistant cover (which I didn't use since I didn't think it was necessary). All for under $40!!
I followed the suggestion of other users and took all the plastic off and all the covers, including the waterproof one (watch out for static electricity!). I let it set out in a room flat for 2 days and it expanded beautifully. It did have a slight smell at first but went away after the first day.
I love that it is huge and can fit my dog all spread out and the best part is easy washing and there are sooo many cute crib sheets out there so you can change up the pattern when you want something new and you can have it match any room!!
I will probably buy another one in the future. Also I did not get paid or receive anything at a discount for this review, just trying to help out all those large breed fur-parents out there!!