title: The value and role of non-invasive prenatal testing in a select South African population.
abstract: BACKGROUND
  Concerns have been raised about the injudicious use of non-invasive prenatal testing (NIPT) using cell-free DNA (cfDNA), which often leads to inaccuracies in interpretation of the role and value of cfDNA in prenatal screening.
  
  
  OBJECTIVE
  To determine the value and role of NIPT in a select South African (SA) population.
  
  
  METHODS
  A retrospective review of patients who elected to have NIPT between 1 October 2013 and 30 June 2015 at the Morningside Mediclinic Maternal and Fetal Medicine Centre in Johannesburg, SA. Patients had NIPT after either combined first-trimester screening (CFTS) or a second-trimester ultrasound scan. Data were collected on details of the first- and/or second-trimester screening, results of the NIPT, invasive tests done, decisions made in the event of abnormal results, and pregnancy outcomes.
  
  
  RESULTS
  Overall, 3 473 first- and second-trimester fetal assessments were done at the centre during the study period, and 2.3% of patients (n=82) elected to have NIPT. The majority of these individuals elected to have NIPT on the basis of positive findings on CFTS, or markers of aneuploidy detected on a second-trimester ultrasound scan. Of the tests done, 97.6% produced results. Of those with no results, one did not meet quality metrics and the other had a low fetal fraction of cfDNA. There were two abnormal NIPT results, one indicating a high risk of trisomy 13 and the other a triploidy. Patients who screened negative elected not to have an invasive test.
  
  
  CONCLUSIONS
  The value of NIPT in this study was that it made it possible to avoid a number of invasive tests. NIPT had a role in contingency screening.
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. nandipha.mnyani@gmail.com.
authors.forename: C N
authors.initials: CN
authors.lastname: Mnyani
authors.forename: E
authors.initials: E
authors.lastname: Nicolaou
authors.forename: S
authors.initials: S
authors.lastname: Bister