From The New Yorker:
Finally, at four-thirty in the afternoon, the contractions began coming five minutes apart, and they set off in their Jetta, with the infant car seat installed in the back. When they reached the hospital admissions desk, Rourke was ready. The baby was on the way, and she was eager to bring it into the world as nature had intended.Dr. Atul Gawande's history of modern obstetrics in the US is one of the most interesting and clearly written articles I've ever seen on the subject. He takes a big-picture view of childbirth and the move across the 20th century to systematically decrease mother and infant mortality rates, the triumph of C-sections over equally/more effective [but harder to teach] forceps, and the most unassuming source of revolution: a pioneering female anesthesiologist named Virginia Apgar.
As an MD himself, you won't be surprised he makes only a little room for skepticism about doctors' and hospitals' motivations and their push to C-sections [and scheduled C-sections], but he does at least recognize that there are real tradeoffs, not just progress:
And yet there’s something disquieting about the fact that childbirth is becoming so readily surgical. Some hospitals are already doing Cesarean sections in more than half of child deliveries. It is not mere nostalgia to find this disturbing. We are losing our connection to yet another natural process of life. And we are seeing the waning of the art of childbirth. The skill required to bring a child in trouble safely through a vaginal delivery, however unevenly distributed, has been nurtured over centuries. In the medical mainstream, it will soon be lost.ANNALS OF MEDICINE - "THE SCORE: How childbirth went industrial." [newyorker.com]
 Of course, that Jetta mention makes me wonder if another unmentioned topic--socioeconomic and cultural gaps in insurance and treatment--have any impact as well.