I prefer to make a residential hospital, have the staff as the family living there, and teleport in whichever sims need to go there. It's the easiest way if you're doing storytelling or pictures, because you have full control over poseboxes, buy/build, and similar. However, I never save after teleporting in sims, and I honestly don't know how safe that would be. Maybe someone else have thoughts on that matter.
For baby births and the like, you could temporarily move in the mother, let her have the baby, save, and then teleport them back to the regular house.
There is a hospital mod by Chris Hatch at BAS (it's an adult site, just so you're warned), but I have never tried this mod, so I'm not sure how it works.
There's also a mod that lets toddlers go to community lots. Maybe babies, too (but again, I've never tested it properly - I think it had a lot of issues).
http://modthesims.info/d/303968