Blood Test Provides More Accurate Prenatal Testing For Down Syndrome
Studies have shown that the new fetal DNA tests do a better job. They're less likely to flag a normal pregnancy as high risk. "They're much more accurate than current screening tests, but they are not diagnostic tests in the sense that amniocentesis is."
Even though the newer blood tests do look at fetal DNA, they can't give a definitive answer like an amniocentesis can because they're analyzing scraps of fetal DNA in the mother's blood that are all mixed up with her own DNA.
DNA Blood Test Gives Women A New Option For Prenatal Screening