Ultraschall Med 2015; 36 - A233
DOI: 10.1055/s-0035-1558759

Impact of non-invasive prenatal Testing (NIPT) on invasive procedures in a tertiary referral center

A Kawecki 1, A Wolter 1, J Degenhardt 1, C Enzensberger 1, R Axt-Fliedner 1
  • 1Abteilung für Pränatalmedizin und gynäkologische Sonografie, Universitätsklinikum Gießen und Marburg

Purpose: To investigate the influence of NIPT on the frequency of invasive procedures in a tertiary referral center.

Methods: Retrospective data analysis was conducted on pregnancies that presented for first trimester screening and 2nd trimester anomaly scan during a 16 months period before and after the introduction of NIPT.

Results: 2340 and respectively 2929 cases before and after introduction of NIPT were enrolled. Before the introduction of NIPT, 144 invasive procedures were performed following first trimester screening (93 amniocentesis, 51 chorionic villous samplings). After the introduction of NIPT, 110 invasive procedures were performed (67 amniocentesis, 43 chorionic villous samplings) and 105 NIPTs. The main indications for invasive testing varied before and after the introduction of NIPT as follows: in cases with major fetal abnormalities – before NIPT 29% vs. 45% after NIPT, maternal age > 35yrs or abnormal results after first Trimester screening – 38.5% vs. 18%, history of chromosomal abnormality (4% vs. 1.8%). In patients with increased NT or soft marker for trisomy 21, the frequency of invasive testing remained unchanged (13% vs. 15.6% and respectively 7% vs. 5.5. After the introduction of NIPT, 5 cases (5%) necessitated additional invasive testing due to abnormal NIPT results.

Almost 50% of the invasive procedures were performed before NIPT in cases of women at risk for aneuploidies due to maternal age > 35 years or abnormal first trimester screening or due to history of autosomal trisomies or soft markers for trisomy 21. After the introduction of NIPT only 27% of procedures were performed in this cohort.

Conclusion: The proportion of invasive testing after the introduction of NIPT was reduced in cases of high risk patients presenting without major fetal abnormalities or increased nuchal translucency.