Noninvasive prenatal test or DNA test can reveal fetal genetic abnormalities in a fetus through a simple test maternal blood from the tenth week of pregnancy. In recent years there has been an important alternative to invasive procedures such as amniocentesis, which can endanger the fetus. The results position it as a revolutionary technique, since they offer a 99% screening for Down syndrome (chromosome 21) and 95% for trisomy 13 and 18; no defects are detected. Noninvasive prenatal diagnosis is not recommended if you have received in less than six months a blood transfusion or bone marrow transplant. Although clinical use in Spain is from a couple of years ago, still it has not been extended due to its high cost.