Pregnancy is far more invasive than an organ transplant, had much longer side effects, and messes up your life much more than an organ transplant. You're right, they're not the same. For a woman that does not want a child, a pregnancy is much, much worse. :)
The radical feminists argue what I'm telling you right now - that women have a right to their own bodies. It has nothing to do with men because men cannot get pregnant. I don't know how you aren't understanding this; it is about a woman's right to choose who uses her body and for what purposes it is used. It has nothing to do with being a mother or being a father and everything to do with personal bodily rights.
You didn't understand Live's point about indentured servitude. The child being born is not indentured servitude. The child using your body against your will is indentured servitude. I don't currently know the laws on parents with children they don't want, so I can't comment on that and it's completely irrelevant to the issue of women's bodily rights.