I'd like to know this, too.
OP, you CAN take a year off. I've heard of that a lot. It's also totally possible to have a baby during medical school while staying with your current class, assuming you have a fairly uncomplicated pregnancy (as in, you aren't put on strict bedrest for 6 months, for example). IMO, this will depend on the supportiveness and availability of your SO and family, but with class capture (which most schools seem to have now) actually attending lecture seems to be largely optional. I am due at the end of September, and I start medical school in August. I will have to go in 2 days a week for my doctoring course and I'll have to go in for tests but otherwise I can stay home with my kid until they're old enough to go to daycare with their big sister. My husband already works from home 2 days a week and can do that more often if he needs to, so that's what we'll do on days I have to go into school.
I have no idea about residency. Ask me again in 4 1/2 years.
Good luck with that!