If they're real friends they won't ditch you because you want some ocassional adult time and conversation. I'd try to do both if you want to take a soft approach - some outings with and conversations about kids, but also ask for what you want in the other direction - be willing to compromise. If you do it honestly and politely it should be ok.
When the conversation at dinners has gone on too long about kids, change the subject. Be prepared w/topics.
Good luck!
