Without reading any replies...
I think your son is likely to suffer more damage from having an attitude like that to live under (the "boys can't play with prams," BS) than having a pram.
Do fathers not ever partake in parenting their babies?
It's the same with cooking sets and whatnot... do men never become chefs? Do males not know how to use an oven? Etc etc.
Really... my brother played dolls with me. He's a d*ck, but he's not some girly-man homosexual... which, let's face it, is what these men (with attitudes like that) are worried about.