Trial by Dutch Laboratories for Evaluation of Non-Invasive Prenatal Testing. Part I - Clinical Impact

Abstract

OBJECTIVE: To evaluate the clinical impact of nationwide implementation of genome-wide Non-Invasive Prenatal Testing (NIPT) in pregnancies at increased risk for fetal trisomies 21, 18 and 13. METHOD: Women with elevated risk based on first trimester combined testing (FCT ≥ 1:200) or medical history, not advanced maternal age alone, were offered NIPT as contingent screening test, performed by Dutch University Medical laboratories. We analyzed uptake, test performance, redraw/failure rate, turn-around time and pregnancy outcome. RESULTS: Between April 1st and September 1st, 2014, 1413/23232 (6%) women received a high-risk FCT result. Of these, 1211 (85.7%) chose NIPT. 179 women had NIPT based on medical history. 1386/1390 (99.7%) women received a result, 6 (0.4%) after redraw. Mean turn-around time was 14 days. Follow-up was available in 1376 (99.0%) pregnancies. NIPT correctly predicted 37/38 (97.4%) trisomies 21, 18 or 13 (29/30, 4/4 and 4/4 respectively). 5/1376 (0.4%) cases proved to be false positives: trisomies 21 (n = 2), 18 (n = 1) and 13 (n = 2). Estimated reduction in invasive testing was 62%. CONCLUSION: Introduction of NIPT in the Dutch National healthcare-funded Prenatal Screening Program resulted in high uptake and a vast reduction of invasive testing. Our study supports offering NIPT to pregnant women at increased risk for fetal trisomy.