To identify birth defects such as Down syndrome, chromosome abnormalities, and other genetic diseases, prenatal test is now widely accepted as a routine for pregnant women. Common tests including amniocentesis, ultrasonography, etc. can be basically divided into invasive or non-invasive methods according to the way of their appliance. An invasive method involves probes or needles being inserted into the uterus, and , on the contrary, non-invasive techniques adopt ultrasonography and maternal serum screens to gain the information of the fetus. Here we present a brief introduction to the most common kinds of prenatal tests along with some basic knowledge of genetic consultation.
