I would also like to add that we can tend to be morons.
But I agree that when we are told a problem we tend to immediately start thinking how we can fix it. I would ask him what he sees his role as. I would explain to him that you need him as your advocate -- the word "protector" is the one that struck home with me. My wife made it clear that she needed to focus on "making baby" and I needed to handle the outside world -- for her and for the baby.
Most guys like the idea of being the protector - the knight in shining armor. If you can put his role in what he can be DOING, that usually helps. Keep in mind that he may be frustrated in his inability to do anything about your condition. If so, helping him to channel that frustration into good actions will help everyone.