Hi lngilbert--
I would agree with the suggestions here about asking him to consider why he wants a child, and also spending time with children to see ALL the moments, not just the Kodak ones.
I really feel for you...been there and done that. It's awful, really awful...some days I cried so hard I almost made myself sick. My husband really wanted kids.
We are still together, but now he is going through a difficult time because he doesn't like his job or field of work. He stayed where he was because he thought we were going to have a family, but now that we're not...well, he has the luxury of a mid-life crisis! I think that if a person goes through life assuming they're going to go down a certain path, and then they don't, it's a bit of a shock to the system. So I try to remember that and give him some space to figure out what he wants to do.