title: Chorionic villus sampling in the cell-free DNA aneuploidy screening era: careful selection criteria can maximise the clinical utility of screening and invasive testing.
abstract: OBJECTIVE
  To quantify the impact of cell-free DNA (cfDNA) screening on chorionic villus sampling (CVS) test indications and outcomes in a tertiary maternity service.
  
  
  METHODS
  Retrospective cohort study of all CVS procedures performed for any indication on singleton pregnancies at The Royal Women's Hospital, Melbourne, and at Women's Ultrasound Melbourne, Australia, between August 2008 and February 2015. Karyotypes were classified according to pathogenicity and detectability by standard cfDNA screening panels.
  
  
  RESULTS
  A total of 2051 CVS procedures, 25 373 twelve-week scans and 2394 cfDNA tests were performed. The CVS rate per 12-week scan fell from 9.8 to 3.9% following introduction of cfDNA screening. The yield of pathogenic chromosomal anomalies per CVS increased from 12.9 to 25.2%, with 70% of pathogenic results now comprising T21, up from 52%. Sixteen (5.3%) of the pathogenic chromosomal abnormalities identified on CVS would not have been predicted by current cfDNA tests.
  
  
  CONCLUSIONS
  There is an evolving tension between improved screening performance for common aneuploidies offered by cfDNA testing, and the increasing diagnostic utility of molecular karyotyping. However, the risk of not identifying pathogenic chromosomal abnormalities is low if cfDNA screening is offered in the absence of a structural fetal anomaly, increased nuchal translucency or relevant family history. © 2017 John Wiley & Sons, Ltd.
authors.affiliation: Pregnancy Research Centre, Department of Maternal Fetal Medicine, The Royal Women's Hospital, Parkville, VIC, Australia.|The University of Melbourne, Department of Obstetrics and Gynaecology, The Royal Women's Hospital, Parkville, VIC, Australia.|Ultrasound Department, Pauline Gandel Women's Imaging Centre, The Royal Women's Hospital, Parkville, VIC, Australia.
authors.forename: Stefan C
authors.identifier: http://orcid.org/0000-0002-5172-3263
authors.initials: SC
authors.lastname: Kane
authors.affiliation: Pregnancy Research Centre, Department of Maternal Fetal Medicine, The Royal Women's Hospital, Parkville, VIC, Australia.|Ultrasound Department, Pauline Gandel Women's Imaging Centre, The Royal Women's Hospital, Parkville, VIC, Australia.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Reidy
authors.affiliation: Victorian Clinical Genetics Services, Parkville, VIC, Australia.
authors.forename: Fiona
authors.initials: F
authors.lastname: Norris
authors.affiliation: Ultrasound Department, Pauline Gandel Women's Imaging Centre, The Royal Women's Hospital, Parkville, VIC, Australia.|Women's Ultrasound Melbourne, Parkville, VIC, Australia.|The University of Melbourne, Departments of Medicine and Radiology, Parkville, VIC, Australia.
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Nisbet
authors.affiliation: The University of Melbourne, Department of Obstetrics and Gynaecology, The Royal Women's Hospital, Parkville, VIC, Australia.|Ultrasound Department, Pauline Gandel Women's Imaging Centre, The Royal Women's Hospital, Parkville, VIC, Australia.|Women's Ultrasound Melbourne, Parkville, VIC, Australia.
authors.forename: Louise H
authors.initials: LH
authors.lastname: Kornman
authors.affiliation: Pregnancy Research Centre, Department of Maternal Fetal Medicine, The Royal Women's Hospital, Parkville, VIC, Australia.|The University of Melbourne, Department of Obstetrics and Gynaecology, The Royal Women's Hospital, Parkville, VIC, Australia.|Ultrasound Department, Pauline Gandel Women's Imaging Centre, The Royal Women's Hospital, Parkville, VIC, Australia.|Women's Ultrasound Melbourne, Parkville, VIC, Australia.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Palma-Dias
mesh_terms: D000328:Adult; D000782:Aneuploidy; D001315:Australia / Q000453:epidemiology; D015193:Chorionic Villi Sampling / Q000379:methods / Q000706:statistics & numerical data*; D025063:Chromosome Disorders / Q000175:diagnosis* / Q000453:epidemiology; D004247:DNA / Q000032:analysis / Q000097:blood; D005260:Female; D006801:Humans; D007621:Karyotyping; D018579:Patient Selection; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods / Q000706:statistics & numerical data; D012189:Retrospective Studies
chemical_list: D004247:DNA