title: Multi-centre first-trimester screening for Down syndrome in the Netherlands in routine clinical practice.
abstract: OBJECTIVE
  This is the first report on the results of a first-trimester combined-test screening programme in the Netherlands in a multi-centre routine clinical setting.
  
  
  METHODS
  Between July 2002 and May 2004, blood samples were taken from subjects in 44 centres in the Netherlands and sent to our laboratory to assay for maternal serum concentrations of fbeta-hCG and PAPP-A. Fetal nuchal translucency (NT) was measured in the participating centres at a gestational age (GA) of 10-14 weeks. Results of those pregnancies for which a combined biochemical and NT risk was calculated were included in the epidemiological analysis of this study.
  
  
  RESULTS
  A total of 4033 singleton pregnancies were included in the analysis. The median maternal age of the analysed group was 36.5 years. The distribution of GA was biphasic, with median GA of 10.3 and 12.1 weeks, respectively. The detection rate using the combined ultrasound and serum screening at a cut-off level of 1 in 250 was 71% (15/21), with a screen-positive rate of 4.7%.
  
  
  CONCLUSIONS
  The results of this study show that the first-trimester combined test is suitable as a prenatal screening test in a multi-centre routine clinical setting in the Netherlands. Strict performance evaluation should identify weaknesses in the organisation that impair the performance of the test. Here, the performance of NT was especially identified as a candidate for improvement.
authors.affiliation: Diagnostic Laboratory for Infectious Diseases and Perinatal Screening, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands. Peter.Schielen@rivm.nl
authors.forename: P C J I
authors.initials: PC
authors.lastname: Schielen
authors.forename: M
authors.initials: M
authors.lastname: van Leeuwen-Spruijt
authors.forename: I
authors.initials: I
authors.lastname: Belmouden
authors.forename: L H
authors.initials: LH
authors.lastname: Elvers
authors.forename: M
authors.initials: M
authors.lastname: Jonker
authors.forename: J G
authors.initials: JG
authors.lastname: Loeber
mesh_terms: D000293:Adolescent; D000328:Adult; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D048208:Nuchal Translucency Measurement / Q000592:standards; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis; D011785:Quality Assurance, Health Care
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A