"Natural" childbirth is when the mother stops work, squats in the field, delivers the baby, and puts it to her breast before going back to her job.
What we do in hospitals is NOT natural childbirth, IMHO, no matter how few interventions there are. I had one of my five children without so much as a Tylenol during my entire labor, but I wouldn't call it 'natural', seeing as how I was hooked up to a fetal monitor, had my membranes ruptured, and was on an IV the whole time. Home birth with a midwife in attendance would be the closest thing to 'natural' for the average woman, I should think........but again, that's just my opinion.
Nursing News