i think margo, that part of the reason birth has become more expensive and more risky is becuase women giving birth in obstetric led units, rather than birth centres or home , which is the rarity.. are expected to labour under textbook conditions, that go against many natural principles of birth.
the c.s rate on Ina May gaskin;s The Farm birth commune is around 2 % compared to averages of 25 % upwards in other parts of the USA. Ok, the numbers that deliver there are small, but it is still noteworthy.. women who labour according to their own bodies needs, with one to one support from someone they know and trust, who can move, sit in the bath, lie down, stand , eat and drink as they wish to labour much more effectively.
being in a brightly lit delivery room with no lock on the door, a shared bathroom, noise, etc can be enough to stall labour
and then if you are not progressing as fast as you 'ought', then you are given drugs to make you contract more or your waters are broken and you are hurried along.
not ideal circumstances at all
I am not saying that intervention is never necessary, of course it is ,but probably not as often as it is done.