title: First trimester ultrasound screening for Down syndrome based on maternal age, fetal nuchal translucency and different combinations of the additional markers nasal bone, tricuspid and ductus venosus flow.
abstract: OBJECTIVE
  To examine the performance of screening for Down syndrome based on maternal age, fetal nuchal translucency (NT) and different combinations of the additional ultrasound parameters: nasal bone (NB), tricuspid flow (TF) and ductus venosus (DV).
  
  
  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 crown rump length, NT, NB, TF and DV were measured. In each case, the added value of the additional markers NB, TF and DV were compared with screening for trisomy 21 based on maternal age (MA) and NT thickness alone.
  
  
  RESULTS
  A total of 1916 pregnancies met the inclusion criteria, including 1823 fetuses with a normal karyotype and 93 with trisomy 21. Screening based on MA, fetal NT and one, two and three of the additional ultrasound markers resulted in a detection rate of about 80%, 87% and 94%, respectively for a false positive rate of 3%.
  
  
  CONCLUSIONS
  Detection rates for trisomy 21 in first trimester ultrasound screening are substantially higher if all three additional markers rather than just one are assessed.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Tuebingen, Tübingen, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Abele
authors.affiliation: Department of Obstetrics and Gynaecology, University of Tuebingen, Tübingen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Wagner
authors.affiliation: Fetal Medicine Foundation USA, Dayton, OH, USA.|Division of Maternal Fetal Medicine, Wright State University, Dayton, OH, USA.
authors.forename: Jiri
authors.initials: J
authors.lastname: Sonek
authors.affiliation: Department of Obstetrics and Gynaecology, University of Tuebingen, Tübingen, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Hoopmann
authors.affiliation: Department of Obstetrics and Gynaecology, University of Tuebingen, Tübingen, Germany.
authors.forename: Sara
authors.initials: S
authors.lastname: Brucker
authors.affiliation: Department of Obstetrics and Gynecology, Celal Bayar University, Turkey.
authors.forename: Burcu
authors.initials: B
authors.lastname: Artunc-Ulkumen
authors.affiliation: Department of Obstetrics and Gynaecology, University of Tuebingen, Tübingen, Germany.
authors.forename: Karl Oliver
authors.initials: KO
authors.lastname: Kagan
mesh_terms: D004314:Down Syndrome / Q000000981:diagnostic imaging*; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008423:Maternal Age; D009295:Nasal Bone / Q000000981:diagnostic imaging*; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012189:Retrospective Studies; D014262:Tricuspid Valve Insufficiency / Q000000981:diagnostic imaging*