I never had an Ob (public for all) & truthfully can't see why you need one unless it's more for convenience... a few posters have mentioned elective CS, or knowing who they will have for the delivery.. that kind of thing, I get, but apart from that, even if there are complications (as there were with my third labour) you just see the Ob who's on at the time. With my second & fourth labours I never saw a doctor of any sort, just a midwife.

JMO and of course I speak from the POV of never having had one but I don't know what pre-natal care they would give that would be any different?