That would certainly be a great way to prevent genetic disorders for future generations, just disallow anyone with a pre-disposition from reproducing and/or being born.

That seems like an odd way to look at reproduction. Would you rather like 50 years and die of cancer or not have lived at all?

It's one thing to make a decision when there's medical evidence during the pregnancy that can be tested but when you're only talking about a statistical risk that something may or may not occur...