Down's disease is a special chromosomal disorder that often occurs in excess of chromosome 21. Few know, but not only are there external, visible signs (everyone recognizes a person with a down-path), but it is also associated with serious health problems (heart disease). We visit my little son regularly at the GOKI (National Institute of Cardiology) for other reasons and always run into parents raising a child with Down's syndrome. Sometimes he is surprised because we think they are all born with severe mental disabilities, even though they can be smart enough. At the 12th week of pregnancy, they are screened with ultrasound, where they mainly look at the thickness of the nape of the neck. In fetuses with down, it is thicker than in their healthy counterparts. When I was pregnant, it was possible to have a combined test (it still is), which also means taking blood in addition to the ultrasound, and at week 16 I still had AFP, which had already been canceled. They also gave a risk value that increases with the mother’s age. So the older the mother, the better her chances of having a Down baby.