But they don't stay cute little kids, so that's not a good basis for deciding to have one. Medical advances have resulted in most of them living to middle age, albeit with quite of lot of medical support. Some parents think ahead to the future and decide it's better not to have a mentally and physically disabled child who will probably outlive them, and almost certainly outlive their ability to provide the care that a Downs syndrome adult needs during the latter years of a disease-shortened life.
I know someone who chose not to do testing for Downs syndrome with her first pregnancy (which was IVF, so could have been tested before the embryos were even transferred into her), because she and her husband had decided they would go ahead and have a Downs baby. Fast-forward to 4 years later, and she's now trying for another baby. This time she and her husband decided, based on their age and the existing child, that they did not want to risk a Downs baby this time, and so will do preimplantation genetic diagnosis. They feel it's irresponsible to take a high risk that their daughter will end up saddled with the dual strain of dealing with infirm elderly parents and a Downs sibling, while she's still very young herself, and later having sole responsibility for the Downs sibling, who would likely be in the process of dying while the daughter has young children of her own.
So not everyone who decides not to have a Downs baby just assumes that Downs automatically means a life not worth living. Some people balance the whole picture and decide that in their own particular situation, they shouldn't bring another Downs person into the world.
Good posts Shrinker.
:)