I imagine you mean that the kid would be turned into medical waste while "he" is a fetus and does not have a functional brain, not after he becomes a he and is later born. :p Wording matters.
Pro-abortion people would argue if you don't want the child, you should put them up for adoption. I don't have a problem with this. I have a problem with some of the same people saying that certain people should not adopt. They want to put a huge influx of orphans in the system, but they refuse to pay for that system and they will only allow a minority of people to adopt. The numbers simply do not add up.
To answer your question, if the family is going to be abusive, I think abortion is better. I have been through abuse and it is not something I would want to subject another person to, especially if that person is special needs, such as myself. Abuse leaves a huge impression in victims lives and alters them greatly. No one should carry that sort of pain with them.