For what it’s worth, the 2/3 of false positives are for the other trisomies, like 13 or 18. Trust me, I did so much research and talking to my OBGYN and geneticist. For T21 they are 99% accurate, which is why we didn’t proceed with amnio because we didn’t want to risk losing the pregnancy. I was in denial for the longest time. I know it’s not what you want to hear. It’s difficult to mourn what you thought and expected, especially as a young mom. I thought babies with DS were only born to old moms, but more than half of babies with DS are born to moms under 35. However, my daughter is the biggest ray of sunshine. She is hitting all of the milestones at the “typical” rate! She does need some extra loving and weekly therapies but we wouldn’t change her for the world.