There's a case in California where a doctor refused to artificially inseminate a lesbian couple because of his moral beliefs (
Link). Apparently more and more doctors are refusing to service people because of their moral beliefs (everything from this to blood transfusions). Quite simply, the question is should doctors be able to refuse treatments they are morally opposed to?
Personally, if the doctor is in private practice and it isn't a life or death situation, I think the doctor should be able to.