This is why I tell people that our "current plan" (stress on "current") is to birth naturally in a birth center. And why I say that we'll see how it all turns out, whether I'll really make it through labor without pain meds, without any interventions, etc. Because this fallen world is unpredictable (and so is my ability to handle pain!).
I am a huge supporter of natural birth (though I'm sort of an unqualified supporter until I've gone through it myself), but I think many - and I'm not saying all - in the natural birth camp are missing one piece of the puzzle in the perspective. We women are told to "believe in our body" and "believe in God's natural design for birth", or whatever other variation on the natural childbirth mantra. I believe that God did design a woman's body for birth, and that it doesn't usually have to be a medical event.
But (and that's a big but) this earth is not the perfect "good" world that God originally created. As a Christian I have to remember that this world is darkened by sin, which affects every aspect. Childbirth, of all things, even got individual note in the curse recorded in Genesis! That means that our bodies do not always work according to their perfect original design, that means that childbirth is painful, and that means that we can't guarantee that childbirth will be a "a natural, nonmedical event". Tragic events happen, and more simply, some women don't have the ability or desire (or in some cases, haven't been prepared) to handle pain.
There is a lot of controversy over interventions in labor and delivery, and I think the general obstetrician needs to seriously reconsider a lot of her practices. But the fact is that managed care, pain meds, etc. usually still result in healthy, happy babies. And that's a much bigger thing than whether or not a woman chooses to have an ultrasound in pregnancy, or had an episiotomy in labor, or an epidural, or an induction, or any of the other many intervention options. It's good to remember the big picture - in this case a picture of a cute little baby :-D.
On the flip side, I do highly recommend Natural Childbirth: The Bradley Way and The Thinking Woman's Guide to a Better Birth for education on obstetric care and alternatives. Just keep it all in perspective, please.