Advanced Firsttrimester Screening-A critical review of the fundamental studies and suggestions for improvement

Objective: Firsttrimester screening (FTS) uses a common background risk [1], measurement of the nuchal translucency (NT) [2,3] and determination of Papp-A and fß-Hcg [4,5] to compute an adjusted risk for Down´s syndrome. All mentioned parameters correlate to an elevated risk but only NT, Papp-A and fß-Hcg are changed by the presence of genetic abnormalities. The maternal age just gives a common statistical information which is not depending on the individual fetus. Therefore it is doubtful whether the inclusion of the background risk is a meaningful strategy. Methods: The following points describe how the FTS ca…