“I’ve read about many cases where it was determined the baby would have downs and the mother urged to abort, but once born, the baby showed no signs of downs. Is that going to be a problem with autism testing too?”
There are newer tests being developed that can tell with 100% accuracy.
The technology for embryo screening is becoming rapidly more accurate and less costly.
I find that hard to believe. The possible way that I can see that happening is if there were and undeveloped twin with Down ’s syndrome in the womb.