Between the 10th and 14th week of pregnancy, the doctor measures the skin fold in the neck of the child using ultra sound imaging. The thicker the fold, the larger the risk for Down Syndrome. Using this simple method, 80% of ill embryos can be recognized.
A thickened neck fold can have more harmless causes. This is why the testing of the neck fold may be combined with an examination of the mother’s blood (serum screening). If these results also point to a malformation, a more precise method is applied (chorion sampling, amniocentesis).