Romy - yes. I think it could well have that efect, but in principle, I believe it too - if it is ok for a woman t terminat because she does not want to be pg and have that baby then it has to be for any reason.
In the end, I think you have to decide whether abortion is accepatable (however distatseful) or not. I am always amazed at the people who are morally totally opposed to abortion - those for whom life from conception is human and sacrosanct -who then add 'except in cases of rape'. So why is that life less sacrosanct because of rape?
So, logically, if you accept that a feotus is dependent on a woman's body - part of a woman's body until birth, then she has dominion over her own body, then that dominion is the beginning and end of the decision-making.
Or you could make a distinction like 'once the feotus can feel pain' (a poster on an abortion thread was detailing the developmental stage at which a feotus typically grows the part of the beain which recognises pain) and say that the woman' right to have absolute say over what happens in her body stops at that point.But it shouldn't depend on the 'ifs' and 'buts' of any one feotus over another. That is where it strays into making value judgements about disabled babies.