It does not sound like, as a grown man, he left his mother behind when he married you. How long have you been married (since this is your first child?)? It sounds like there were things not finished with before she died, that he may not have been a very mature husband if he is continuing on in this line.

I don't know what to tell you about how to help him with that, it does not sound like he wants to change in any way, he just does not want his mother to be dead (as opposed to grieving her death). I would say, have him see a therapist but I don't see how you could get him to view his actions as immature/not appropriate for being married and a father soon.

There is a difference between remembering good times one had with one's mother; my husband has fond memories of he and his mother going to a special store and getting ice cream; even as a husband/father, on each of their birthdays, they would send each other $1 to buy an ice cream :-) and my father certainly loved him mother, he forgot his bank card pin number of 20+ years the day he learned of her death, but I think your husband is trying to carry his mother into the future rather than grieve her loss. Naming a child for their mother is appropriate, commenting on the child's looks in relation to their mother before the child is born (what if the child looks like his father or himself :-) and leaving the child's mother out of the equation; I am with you that is not appropriate and hurtful (but not deliberately, he is just immature and did not separate from his mother completely before marrying you -- he needed to "let go" of mothering and focus on "partnering" and he did not do that and now it may be even harder than ever).