Women considering it should heavily think about and, to be frank, agonize over the decision. They are looking to terminate a life, regardless of what other people say about it "just being a cluster of cells" (something I disagree with other pro-choicers, since those cells can and will become a human being).
If, for example, a pair discuss this weighted situation and agree to go through with it, I understand, respect, and agree with this, since they did not take the decision lightly. They'd understand the ramifications of what they're about to consent to. That's choice. This also includes medical reasonings too, such as the child being severely deformed or mutilated (but this also runs the risk of going into eugenics territory, too -- "Oh, I don't want a Down Syndrome baby" for example, instead of "if my baby doesn't have a fully formed brain or heart, then we should be merciful", et cetera).