Krusty - I mean this - and I want you do REALLY consider it. You are an incredibly gifted photographer - offer to take pictures - if they are "ok"
with it - even offer to be "on call" for the birth time ... it is going to be the most happy day of their lives and to NOT have to worry about getting it all on film themselves would be SUCH a blessing - and you KNOW them - so you have a great understanding of getting "the moment" down.
I'm very serious here ... offer them your gift of photography ... both color and black and white - and don't worry if photographing people isn't something you've done much of - just think of them like your dogs that you take such cute pictures of all the time!