I think that abortion should be allowed, but realistically if you can't support a child it will suffer. Of course it's your fault for getting pregnant, but if you can't even manage to raise the child I think it only fair to abort it. Aborting a child who will die or be severely stunted in some way is not a choice, it should frankly be a requirement. A child can not support a child, and thus should be at least considered for abortion, though in some cases parents are willing to chip in and help, leaving me a bit split on a certain yes or no.
I do believe, however, that a perfectly sane human with the capability to support a child should not be able to abort, but it's circumstantially unfair to certain people, particularly rape victims. Simply getting rid of a child just because you don't feel like raising a child is just petty to me. You know what you're getting into when having sex, and if you're not ready to accept the consequences then you should not be throwing your genitals around (that means us, too, boys).