Leaving after 4 hours is completely voluntary - and usually only happens in birth centres or in caseload midwifery. People going general public with midwives will usually stay 2 or three days after a vaginal birth, as opposed to 3-4 in private. Your chances of a natural birth are much better with midwives than obstetricians, all things being equal. We see this year in, year out in the perinatal data in every state in Australia.

I'm very wary of FS/OB's for mum's wanting a natural birth. We tend to find that the inflexibility of their fertility clients (who require treatment at very specific times of the month that can't be "rescheduled" easily) compete with the more flexible needs of their obstetric clients - so they seem to push inductions of labour or caesareans more so than OB's who only practice obstetrics/gynaecology. It enables them to juggle competing commitments better - they can "plan" their labour attendance so that they are available to do fertility treatments when they need to do them. So this is something to be aware of and to ask your FS about. How does he/she manage this?

Good luck