Prenatal diagnostics


Nuchal translucency ("nuchal translucency"), NT measurement

The images on the right show a sonographic measurement of nuchal translucency (physiological fluid accumulation in the fetal neck) in the 11th-14th week of pregnancy.

A thickened nuchal translucency indicates an increased risk for trisomy 21, 18, 13, and various malformations. The additional determination of other parameters from the blood as PAPP-A (pregnancy associated plasma protein A) and free beta-hCG from maternal blood can increase the detection rate of chromosomal abnormalities.

A safe prediction of individual terms of a genetic malformation is therefore not possible - it is merely a statistical statement.



Compared to the previous method, amniocentesis, where 15-20 ml amniotic fluid is aspirated under ultrasonographic control, is a very reliable chromosomal diagnosis. Its result for Trisomy 21, 18, 13 can be obtained by FISH (fluorescence in situ) within 24 hours. The risk of spontaneous abortion caused by the amniocentesis on the other hand lies at approximately 1:250 – 300.