title: Detection of fetal chromosomal anomalies: does nuchal translucency measurement have added value in the era of non-invasive prenatal testing?
abstract: OBJECTIVE
  The objective of this study is to determine what percentage of fetal chromosomal anomalies remains undetected when first trimester combined testing is replaced by non-invasive prenatal testing for trisomies 13, 18, and 21. We focused on the added clinical value of nuchal translucency (NT) measurement.
  
  
  METHODS
  Data on fetal karyotype, ultrasound findings, and pregnancy outcome of all pregnancies with an NT measurement ≥3.5 mm were retrospectively collected from a cohort of 25,057 singleton pregnancies in which first trimester combined testing was performed.
  
  
  RESULTS
  Two hundred twenty-five fetuses (0.9 %) had an NT ≥3.5 mm. In 24 of these pregnancies, a chromosomal anomaly other than trisomy 13, 18, or 21 was detected. Eleven resulted in fetal demise, and ten showed fetal ultrasound anomalies. In three fetuses with normal ultrasound findings, a chromosomal anomaly was detected, of which one was a triple X.
  
  
  CONCLUSIONS
  In three out of 25,057 pregnancies (0.01%), non-invasive prenatal testing and fetal ultrasound would have missed a chromosomal anomaly that would have been identified by NT measurement. © 2015 John Wiley & Sons, Ltd.
authors.affiliation: Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: K D
authors.initials: KD
authors.lastname: Lichtenbelt
authors.affiliation: Department of Obstetrics, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: B D M
authors.initials: BD
authors.lastname: Diemel
authors.affiliation: Department of Obstetrics, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: M P H
authors.initials: MP
authors.lastname: Koster
authors.affiliation: Department of Obstetrics, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: G T R
authors.initials: GT
authors.lastname: Manten
authors.affiliation: Department of Infectious Disease Research, Diagnostics and Screening, National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Siljee
authors.affiliation: Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: G H
authors.initials: GH
authors.lastname: Schuring-Blom
authors.affiliation: Department of Obstetrics, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: G C M L
authors.initials: GC
authors.lastname: Page-Christiaens
mesh_terms: D000328:Adult; D025063:Chromosome Disorders / Q000175:diagnosis*; D002882:Chromosomes, Human, Pair 13; D002887:Chromosomes, Human, Pair 18; D003951:Diagnostic Errors / Q000706:statistics & numerical data*; D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D062145:Maternal Serum Screening Tests; D008875:Middle Aged; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012189:Retrospective Studies; D014314:Trisomy / Q000175:diagnosis*; D000073839:Trisomy 13 Syndrome; D000073842:Trisomy 18 Syndrome