Prenatal tests are divided into two main categories: screening tests and diagnostic tests. Screening tests, such as double, triple, and quadruple screening tests, as well as Fetal DNA tests (NIPT), are performed using a blood sample taken from the mother and assess the risk of genetic anomalies in the baby. Definitive prenatal diagnostic tests, on the other hand, are performed by taking samples from the baby's placenta (Chorionic Villus Sampling - CVS), amniotic fluid (Amniocentesis), or umbilical cord blood (Cordocentesis) using needles of varying thicknesses depending on the procedure type. These samples are meticulously examined in laboratories to determine the baby's genetic structure with the highest certainty.