Are There Prenatal Tests For Down Syndrome Trisomy 21?

Are There Prenatal Tests For Down Syndrome Trisomy 21? The diagnostic procedures available for prenatal diagnosis of Down syndrome are chorionic villus sampling (CVS) and amniocentesis. These procedures, which carry up to a 1% risk of causing a spontaneous termination (miscarriage), are nearly 100% accurate in diagnosing Down syndrome. How do they test for Down