First trimester ultrasound screening for trisomy 21 based on maternal age, fetal nuchal translucency and different combinations of the additional markers nasal bone, tricuspid and…

Objective: To examine the performance of screening for trisomy 21 based on maternal age, fetal nuchal translucency and different combinations of the additional ultrasound parameters: nasal bone (NB), ductus venosus (DV) and tricuspid flow (TR). Methods: Retrospective study at the University of Tuebingen, Germany including women who underwent chorionic villous sampling between 2008 and 2014. Prior to invasive testing, the CRL, NT, NB, DV, and TR were measured. In each case, the risk for trisomy 21 was calculated based on firstly, maternal age (MA), secondly, MA and NT thickness, thirdly, MA, NT and one of the add…