title: Cell-free DNA testing after combined test: factors affecting the uptake.
abstract: OBJECTIVE
  First, to assess what was the uptake of cell free DNA (cfDNA) testing after a combined test and the maternal and fetal factors that influenced this decision, and second, to assess the uptake and factors that influence the choice of invasive testing.
  
  
  METHODS
  This observational retrospective study included 1083 singleton pregnancies who had a combined test for screening for Down syndrome between 11 (+) (0) and 13 (+) (6) weeks. Multivariate logistic regression analysis was used to determine which factors affected the uptake of cfDNA test and invasive testing among risk for trisomies 21, 18, and 13, maternal characteristics and fetal nuchal translucency (NT) thickness.
  
  
  RESULTS
  Two-hundred fifty-seven (23.7%) women had a cfDNA test, 89 (8.2%) had an invasive test, and 737 (68.1%) had no further test. The uptake of cfDNA increased with the risk for trisomies (p < 0.001), maternal age (p = 0.013), and was higher in nulliparous women (p = 0.004). The uptake of invasive test increased with the risk for trisomies (p < 0.001) and NT thickness (p < 0.001).
  
  
  CONCLUSIONS
  This study shows that the uptake of cfDNA testing increases with the risk for trisomies, maternal age, and is higher in nulliparous, whereas the uptake of invasive testing increases with the risk for trisomies and NT thickness.
authors.affiliation: a Fetal Medicine Unit, Obstetrics and Gynecology Service, Clínica Zuatzu , San Sebastian , Spain and.|b Fetal Medicine Unit, Obstetrics and Gynecology Service, BioCruces Health Research Institute, Hospital Universitario Cruces, University of the Basque Country (UPV/EHU) , Biscay , Spain.
authors.forename: Nerea
authors.initials: N
authors.lastname: Maiz
authors.affiliation: a Fetal Medicine Unit, Obstetrics and Gynecology Service, Clínica Zuatzu , San Sebastian , Spain and.
authors.forename: Irune
authors.initials: I
authors.lastname: Alzola
authors.affiliation: a Fetal Medicine Unit, Obstetrics and Gynecology Service, Clínica Zuatzu , San Sebastian , Spain and.
authors.forename: Emerson J
authors.initials: EJ
authors.lastname: Murua
authors.affiliation: a Fetal Medicine Unit, Obstetrics and Gynecology Service, Clínica Zuatzu , San Sebastian , Spain and.
authors.forename: Javier
authors.initials: J
authors.lastname: Rodríguez Santos
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood*; D002474:Cell-Free System; D002755:Choice Behavior; D004247:DNA / Q000097:blood*; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis / Q000235:genetics*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000009:adverse effects / Q000379:methods* / Q000523:psychology; D012044:Regression Analysis; D012189:Retrospective Studies; D018570:Risk Assessment; D055815:Young Adult
chemical_list: D015415:Biomarkers; D004247:DNA
keywords: Aneuploidy; NIPT; cell-free DNA; first trimester pregnancy; prenatal screening