Cotbed mattress

Hey ladies!

So yesterday my mum and partner helped build the cotbed ready for little one's arrival (couldn't wait any longer and now it feels more "real") which is all great and it looks lovely... but i noticed a really strong smell in the room when i went up to bed a while later- after some sniffing by myself and my OH we decided it was definitely coming from the baby's mattress!

My OH thinks its a "damp" smell... I can't quite put my finger on it- its a disgusting smell and (thanks to my super pregnancy nose) I can smell it even now typing this- downstairs!! 

What the heck is this smell? Its a brand new mattress! The mattress i got for my son 5 years ago didnt smell at all! We've got it out for airing but i don't think i can bring myself to put our baby down on it even if the smell did disappear!

Has anyone else had this issue? Can you recommend a good mattress? (thinking to throw this one out and get a different one) 

Thanks for reading x