I sailed through having baby number 1, then had severe pnd with number two. It was absolutely horrendous, but after nearly two years I am feeling so much better. I am now feeling incredibly broody and ready to have a third baby. When we got married I said how much i wanted a big family. My husband however is completely against the idea on the grounds of how ill i became after DD2. He rightly or wrongly assumes that i will become ill again. I feel that i now know the warning signs and would be able to seek help (if needed) far quicker than i did before. i feel like i am now having to beg DH to even consider having a third baby. is it unreasonable to want another baby after pnd??
If he doesn't want another and you do, he has the deciding vote. I want another, DH doesn't, we aren't having another.
However, if it is all about the PND and he would want another if that weren't a factor, get him to talk to a HCP about it. Talk through his fears. It might help anyway, actually, as he could have lots of unresolved feelings about it.