title: Parental Decisions about Prenatal Screening and Diagnosis among Infants with Trisomy 21 in a National Cohort with High Uptake of Combined First-Trimester Screening.
abstract: BACKGROUND
  The aim was to investigate the parental decisions about prenatal screening and diagnosis among infants with trisomy 21 (T21) in a national cohort with high uptake of combined first-trimester screening (cFTS).
  
  
  METHODS
  This was a nationwide population-based study including infants born in 2009-2012. Information from the cFTS, fetal karyotype results and pregnancy outcome was obtained from the Danish Fetal Medicine Database on all women with a cFTS risk assessment. Cut-off for referral for invasive testing was ≥1:300. Karyotype results from pregnancies with no cFTS were obtained from the Danish Cytogenetic Central Registry.
  
  
  RESULTS
  The uptake rate of cFTS was 91.6%, and 82.8% (8,032/9,704) of the screen-positive women opted for invasive testing. Overall, 82.2% (454/552) chose to terminate an affected pregnancy. In the 4-year period, 102 of 232,962 singletons were born alive with T21. The cFTS risk was true-positive, false-negative or not obtained in 21.6, 48.0 and 30.4%, respectively, of these pregnancies.
  
  
  CONCLUSIONS
  In this large national cohort, 4.4 per 10,000 live-born infants had T21. Of 102 infants with T21 from 2009 to 2012, 52.0% were born after the women had not opted for cFTS or were true-positive but declined invasive testing or termination, and 48.0% were born after a false-negative risk assessment.
authors.affiliation: Center of Fetal Medicine, Department of Obstetrics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Caroline Borregaard
authors.initials: CB
authors.lastname: Miltoft
authors.forename: Camilla B
authors.initials: CB
authors.lastname: Wulff
authors.forename: Susanne
authors.initials: S
authors.lastname: Kjærgaard
authors.forename: Charlotte K
authors.initials: CK
authors.lastname: Ekelund
authors.forename: Ann
authors.initials: A
authors.lastname: Tabor
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003657:Decision Making; D003718:Denmark / Q000453:epidemiology; D004314:Down Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D006801:Humans; D010290:Parents / Q000523:psychology; D011159:Population Surveillance / Q000379:methods; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000235:genetics*; D011296:Prenatal Diagnosis / Q000379:methods / Q000523:psychology; D012042:Registries
keywords: Chromosomal abnormalities; Diagnosis; Down syndrome; First trimester; Pregnancy outcome; Pregnancy termination; Prenatal diagnosis; Prenatal screening; Screening; Trisomy 21