Abstract
To evaluate the effectiveness of secondary screening using non-invasive prenatal testing (NIPT) in a routine NHS setting including test performance, turn-around times (TATs) and no-call (failure to obtain result) rates. To examine the influence of maternal and fetal characteristics on test performance. Retrospective cohort. London teaching hospital. A total of 8651 pregnancies undergoing screening for fetal trisomy using NIPT provided by an NHS cell-free DNA screening laboratory-the SAFE laboratory. Screening test evaluation and TATs. Univariate and multivariate logistic regression analysis to identify significant predictors of no-call results and reported by low fetal fraction (<2%), very high fetal fraction (>40%) and processing failure. Test performance, TATs and no-call rates, factors affecting no-call results. Average TAT was 4.0days (95% CI 4.0-4.2days). Test sensitivities for trisomies 21 and 13/18 were 98.9% (95% CI 95.9-99.9%) and 90.4% (95% CI 80.0-96.8%), respectively. The overall no-call rate was 32/8651 (0.37%, 95% CI 0.26-0.52%). The overall risk of a no-call result was influenced by gestational age, dichorionic twin pregnancy, history of malignancy and pregnancies affected by trisomy 13/18, but not by maternal weight or use of low-molecular-weight heparin. High-throughput NIPT can be effectively embedded into a public health NHS setting. TATs of 4days and no-calls of <0.5% were well within clinically desirable tolerances. Gestational age, maternal weight, assisted reproductive techniques, use of low-molecular-weight heparin and past history of malignancy did not have major impacts on test no-call rates and should not constitute reasons for withholding the option of NIPT from women. Turn-around times of 4days, no-call (test failure) rates of 0.37% and highly accurate NIPT can be successfully embedded in the NHS.
Highlights
The United Kingdom National Screening Committee recommended a secondary screening model where women with a high-chance (≥1:150) combined or quadruple test result for fetal trisomy were to be offered non-invasive prenatal testing (NIPT), invasive testing or expectant management.[1]
We report on the performance of secondary NIPT screening conducted entirely in a UK public health setting from a large cohort of pregnancies
The data for this study were derived from a retrospective analysis of prospectively collected data from the clinical implementation of the SAFE test in secondary screening for fetal trisomy between January 2016 and March 2019
Summary
The United Kingdom National Screening Committee recommended a secondary screening model where women with a high-chance (≥1:150) combined or quadruple test result for fetal trisomy were to be offered non-invasive prenatal testing (NIPT), invasive testing or expectant management.[1] Despite a large number of studies reporting on NIPT, most are not comparable to a public health setting as they have been conducted in a research context[2,3,4] undertaken by private laboratories with incomplete reporting of maternal variables and pregnancy outcomes[5,6] or largely undertaken in low-risk populations.[7] there is a paucity of data on the impact of various maternal and pregnancy characteristics on routine NIPT performance in secondary screening. The aim of this study is first, to evaluate the effectiveness of NIPT in a routine National Health Service (NHS) setting with regards to test performance, TATs and no-call rates; and second, to examine the effects of maternal and fetal characteristics, obstetric history and medical history on no-call results
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
