In the end it comes down to your own personal view and living with your own conscience. As I stated earlier, life is challenging enough without also having to deal with Down Syndrome, a physical handicap, etc. so I would not have a problem terminating a pregnancy.
I have two kids of my own and it is tough enough raising healthy kids, and I can only imagine the challenge of dealing with a special needs child.
Here is a counter question:
What happens to this special child when the parents are dead and buried?