Next to me mattress

[SassyPants87]

Expecting baby 2 in a couple of months and I’ve got first kids next to me crib to use. It’s not been long since we last used it (she’ll have just turned 2 when baby is due). Am I supposed to buy a new mattress for the next baby? Or is it still safe to use the one I had which was new when DD1 was born?

I'd use the old one assuming no damp or anything on it.

Technically yes, new mattress new baby.

Is there a dent in it from previous baby's head? I borrowed one from my sister and the mattress was still in really good condition so I did use it.