Even so, might there be a discussion of what rape actually is, say, in light of the case against Julian Assange in Sweden? I think so.
And is it justifiable to take the position that all abortion is immoral? Of course. Morals spring from all sorts of random places and the notion that human life is sacred and begins at conception is one of these.
Equally you can hold a moral position that all life is sacred, like the Jains.
Or that life begins at the point of sentience.
That's the difficulty with morals as the foundation of policy. They are founded on the premises you wish them to be. People with different ones are going to conflict.