“Daley reports that while these non-invasive prenatal tests are more accurate than the combination of blood test and ultrasound—which is probably what I had five years ago—they nevertheless can lead to false alarms as much as half the time. The rarer the condition, the greater the risk of false alarm. And yet they promise things like “99% Accurate, Simple & Trusted.” Worst of all, Daley reports cases where women aborted based on those screening results alone, without getting confirmation from amniocentesis. Three fetuses aborted after high-risk results at Stanford University were later studied and found to be healthy.”

Read more: http://www.slate.com/blogs/xx_factor/2014/12/19/prenatal_testing_predicting_fetal_abnormalities_with_alarming_inaccuracy.html