To understand the absolute monopoly ACOG has established in American maternity care, it is helpful to look more closely at this organization. The American College of Obstetricians and Gynecologists is not a "college" in the usual sense: it is not an institution of higher learning. Nor is it a scientific body. With few exceptions, its members and leaders are not scientists but medical practitioners, and there is nothing in ACOG's mission statement about science. The ultimate proof that ACOG is not a scientific body? Too many of its policies and recommendations are not based on real science. . . .(From Marsden Wagner's, Born in the USA: How a Broken Maternity System must Be Fixed to Put Women and Children First, p. 33, 35-36.)
In truth, ACOG is a "professional organization," which amounts to a trade union. Like every trade union, ACOG has two goals--to promote the interests of its members and to promote a better product, in this case, the well-being of women. But if there is a conflict between these two goals, the interests of its members come first. . . .
American maternity care, then, is under the control of tribal obstetrics. A small group, most of them men, are controlling birth in such a way as to preserve their own power and wealth while robbing women and families of control over one of the most important events in their lives. . . .
Power without wisdom is tyranny. There are plenty of intelligent obstetricians who have lots of knowledge, but intelligence and knowledge do not guarantee wisdom. I have known wise individual American obstetricians, but I see no evidence of wisdom in organized obstetrics in the United States. The maternity care we have in what we like to believe is our free country is obstetric tyranny.
For a look at the facts about homebirth, here's a nice overview from iVillage by Henci Goer.