Non‐invasive prenatal testing for everybody or contingent screening?

Abstract

Key points What's already known about this topic? Non‐invasive prenatal testing (NIPT) for fetal aneuploidies has been quickly implemented worldwide. Different implementation strategies are used for NIPT, either as a first‐tier screening test or as a contingent test after the first‐trimester screening. What does this study add? We argue that offering NIPT as a first‐tier test has several advantages over contingent NIPT:

Current controversies in prenatal diagnosis: Noninvasive prenatal testing should replace other screening strategies for fetal trisomies 13, 18, 21

“…If the cut-off is set at 1:200, PPVs for the FCT are 5.2% for trisomy 21, 4.1% for trisomy 18% and 1.4% for trisomy 13. 15 At 1:1000 this will be worse. These low PPV values are not comparable to the high PPVs obtained for NIPT.…”

“…NIPT for the common aneuploidies (13,18,21) as well as the significantly better PPVs. [12][13][14][15][16][17] While the superiority of NIPT as a screening test is clearly evident, the question arises as to whether NIPT should replace other screening strategies for fetal trisomies 13, 18, 21? We put this question to two experts who debated this issue at the 2023 International Society for Prenatal Diagnosis (ISPD) conference in Edinburgh, UK. The audience was polled before our panelists began their discussions.…”

“…Secondary factors such as timing, societal and ethical aspects and costs should also be considered. 15 This debate focuses on whether NIPT or FCT should be offered as a first-tier test to all pregnant women. This definition is important, as even when using contingent screening strategies, it is the first test that determines the DR, the number of false negatives, and the sensitivity and the specificity.…”

“…This definition is important, as even when using contingent screening strategies, it is the first test that determines the DR, the number of false negatives, and the sensitivity and the specificity. When we compare the numbers for NIPT and FCT there is a huge difference (summarized in van der Merj et al 15 ). Depending on the cut-off, the sensitivity of FCT for trisomy 21 is 80%-90%, while for NIPT, it is >99%.…”

Highlights of the 26th ISPD annual conference, hosted in a vibrant Canadian city along with the Montreal grand prix 2022

“…As always, in recent years, there was a session on applications of cell free DNA. In Montreal, we heard the pros and cons of offering NIPT for aneuploidy to all women or just for those at high risk, 5 but we also heard how it may be useful for identifying maternal viral infections 6 . One of the submitted abstracts described the factors influencing uptake of NIPT and noted that it is not only personal values and beliefs influencing choice but also out‐of‐pocket costs of NIPT that hinder equal access to this technology 7 .…”