Hypothetical

It is common for doctors to notify pregnant women when it is determined that the enwombed one has Down Syndrome. The doctor then informs the woman that she can abort if she wishes. What if. . .
Fast forward to a time when the aborting of a Down Syndrome child becomes the norm. Every woman would be subjected to the testing and instructed to abort if the test comes back positive. Then what? What if then a test is developed which determines Autism. If the abortion of one is mandated or normed, then it would follow that positive results for Autism would lead to an abortion. What next? Then a test for IQ? Then a test for. . . What next--or should I say who next?
If we recommend killing enwombed babies because they have three copies of chromosome 21 instead of two, why not a one that has a defect in a gene (like Fragile X)? Why not anyone who has the potential to not reach an IQ higher than 90? Why 90? Maybe 100? Or 110? Or. . .
I think you see where I'm going with this. If it starts, where does it stop? How can we even dare to say that a child who will not be "normal" does not have the right to live? How can we even dare to define "normal"? We cannot dare either, for we know that if we define "normal" and assert that a child who does not fit that definition shall not be granted life; there will come a day when either we will have our life revoked for not being "normal", or we will ultimately exclude all children from being born.
We must speak up.