title: Clinical first-trimester routine screening for Down syndrome in singleton pregnancies in northern Finland.
abstract: OBJECTIVE
  The purpose of this study was to compare the efficacy of both separate and combined maternal serum testing and fetal nuchal translucency measurement in the first trimester screening for Down syndrome in northern Finland.
  
  
  METHODS
  The following screening tests were evaluated: measurement of nuchal translucency (NT) alone; serum screening (pregnancy-associated plasma protein A [PAPP-A] and free beta subunit of human chorionic gonadotropin [beta-hCG]) alone; and combined screening (NT plus PAPP-A and free beta-hCG).
  
  
  RESULTS
  The participants comprised 7534 pregnant women during the 10+0-12+6 weeks of pregnancy. All 7534 women participated in serum screening, and 4765 women participated in combined screening. In the serum screening-alone group, there were 30 cases of trisomy 21, of which 23 (76%) were detected. In the combined-screening group, there were 24 cases of trisomy 21 and 21 (87.5%) were detected. In the combined-screening group NT alone detected 15 cases of Down syndrome (62%).
  
  
  CONCLUSIONS
  Combined screening is the method of choice for Down syndrome screening.
authors.affiliation: Department of Obstetrics and Gynecology, Department of Oulu University Hospital, Finland.
authors.forename: Yrtti
authors.initials: Y
authors.lastname: Valinen
authors.forename: Katrin
authors.initials: K
authors.lastname: Rapakko
authors.forename: Hannaleena
authors.initials: H
authors.lastname: Kokkonen
authors.forename: Paivi
authors.initials: P
authors.lastname: Laitinen
authors.forename: Aydin
authors.initials: A
authors.lastname: Tekay
authors.forename: Tarja
authors.initials: T
authors.lastname: Ahola
authors.forename: Markku
authors.initials: M
authors.lastname: Ryynanen
mesh_terms: D000328:Adult; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D005387:Finland; D006801:Humans; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis*; D011296:Prenatal Diagnosis
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A