title: Uptake of non-invasive prenatal testing (NIPT) and impact on invasive procedures in a tertiary referral center.
abstract: OBJECTIVE
  The introduction of non-invasive prenatal testing (NIPT) by isolation of cell-free fetal DNA from maternal blood is a new diagnostic option in prenatal care. The aim of the study was to investigate the algorithm of prenatal testing before and after the introduction of NIPT in a tertiary referral center and to investigate the influence of NIPT on the frequency of invasive procedures.
  
  
  METHODS
  Retrospective data analysis was conducted of all singleton pregnancies that presented for first trimester screening 17 months before and after the introduction of NIPT (n = 2271). Women were categorized into three risk groups: low risk for trisomy 21 (<1:1000), intermediate risk (1:101-1:1000) and high risk (≥1:100). The choice of diagnostic testing after FTS was analyzed.
  
  
  RESULTS
  1093 (group 1) presented before and 1178 (group 2) after the introduction of NIPT. The rate of high-risk patients was equal in both groups (14.4 vs. 15.4 %). No differences were found with regard to invasive testing (11.6 vs. 11.3 %). NIPT was chosen by 3.7 % (44/1178) in group 2. Of those with NIPT, 72.7 % had a risk estimate of <1:100, but 90.9 % were ≥35 years old. The rate of NIPT among high-risk patients with a normal ultrasound examination was 25 %.
  
  
  CONCLUSIONS
  At present, NIPT is chosen mainly for reassurance by patients not considered to be at high risk. In the high-risk group, NIPT can be offered if the ultrasound examination is normal and the risk is high due to maternal age or serum screening alone. The rate of invasive testing was not reduced in this selected population.
authors.affiliation: Department of Obstetrics and Prenatal Medicine, University Medical School Bonn, Sigmund-Freud-Str. 25, 53105, Bonn, Germany, gwendolin.manegold-brauer@usb.ch.
authors.forename: Gwendolin
authors.initials: G
authors.lastname: Manegold-Brauer
authors.forename: C
authors.initials: C
authors.lastname: Berg
authors.forename: A
authors.initials: A
authors.lastname: Flöck
authors.forename: A
authors.initials: A
authors.lastname: Rüland
authors.forename: U
authors.initials: U
authors.lastname: Gembruch
authors.forename: A
authors.initials: A
authors.lastname: Geipel
mesh_terms: D000328:Adult; D000465:Algorithms; D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008423:Maternal Age; D062145:Maternal Serum Screening Tests; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011295:Prenatal Care / Q000379:methods*; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies; D012307:Risk Factors; D017422:Sequence Analysis, DNA; D062606:Tertiary Care Centers