Uptake of non-invasive prenatal testing (NIPT) and impact on invasive procedures in a tertiary referral center.

Purpose: 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 %.
Conclusion: 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.