that it is not necessarily a moral imperative to suffer in order to save a life - is entirely valid.
It's also a valid point that if you're responsible for the existence of that life then indeed such moral imperative may exist.
Let's not threadjack, but ultimately all the debate about abortion centers on whether or not the fetus is a human life with rights. If it is, the whole pro-choice argument is very very weak, and quite immoral. If it's not, there is no pro-life argument.