Advertising is the art of making whole lies out of half truths. ~Edgar A. Shoaff
Every few years a new screening technology comes zooming down the prenatal pike, sometimes arriving more quickly than we might like. First there was maternal age, with the magical age of 35 as the cut-off. Low maternal serum AFP arrived in the 1980s and the OB community embraced it virtually overnight when ACOG’s Committee on Professional Liability issued a statement that practitioners could be held legally liable if they had not offered this screen to a patient who had given birth to a child with Down syndrome. This was followed in short order by the Triple Screen, The Quad Screen, nuchal thickening, Integrated Screening, etc., each one a statistical notch above its predecessor. The latest iteration – cell-free fetal DNA or Non-Invasive Prenatal Screening (NIPS) - stands head and shoulders above the rest. Two of our colleagues have already discussed the limitations and strengths of NIPS here on The DNA Exchange.*
NIPS is big, as in global big. One lab makes its brochure available in more 20 languages, from Afrikaans to Xhosa (the pregnancy gods must be crazy, dropping pamphlets out of The Cloud). Tens of millions of women around the world are likely to undergo NIPS in the near future. And pregnant women are a “renewable resource” – a whole new batch pops up every day and many women will have two, three, or more children. Competition for market share among labs is stiff and there is little incentive to dissuade women from undergoing prenatal screening. It’s not that labs coerce women to undergo screening, advocate eugenic agendas, or run roughshod over personal autonomy. All labs would support a woman’s right to decline prenatal screening and Lord knows they stay away from the abortion discussion. But if enough women decline, then there is no incentive to offer the screen. The companies have something to sell and will spin their product to attract customers.
Which brings me to the subtly misleading implications of the name Non-Invasive Prenatal Screening. Sure, NIPS is non-invasive. But so is ultrasound, AFP, HCG, etc. All of these screening tests are non-invasive and therefore do not carry a direct risk of fetal loss. NIPS is no different from the rest in that sense. It is superior to other screens in terms of having a very low first positive rates, high positive predictive value, and high sensitivity. But NIPS is still an alternative to other screening tests, not to amniocentesis or CVS.
Yet the websites of companies that offer NIPS communicate a different message that subtly suggests that NIPS is in fact an alternative to amniocentesis/CVS instead of an alternative to, say, the Integrated Screen:
- While there are diagnostic genetic tests available, like amniocentesis or chorionic villus sampling (CVS), these are invasive and carry a risk of miscarriage. The ******** prenatal test requires only a blood draw
- Consisting of a simple, in-office blood test, the ****** test delivers accurate genetic information safely, non-invasively—without the risks of invasive procedures, such as amniocentesis or CVS.
- Diagnostic tests such as amniocentesis or chorionic villus sampling (CVS) are accurate for detecting fetal trisomies, but they are invasive and pose a risk for fetal loss.
- Our ******* test is a “noninvasive” approach to provide a high degree of accuracy for select chromosome information, without the risk of miscarriage associated with an invasive procedure.
First we thought the PC was a calculator. Then we found out how to turn numbers into letters with ASCII – and we thought it was a typewriter. Then we discovered graphics, and we thought it was a television. With the World Wide Web, we’ve realized it’s a brochure. ~Douglas Adams
The suggestion that NIPS is a diagnostic test is further reinforced by reassuring text in large, appealing fonts – Comprehensive, Accurate, Trustworthy, and, my personal favorite, No Confusion. Such wording conflates screening tests with diagnostic tests. Who could resist a test that boasts to be >99% accurate, especially when combined with images of smiling, beautiful parents and babies so cute that you wish your touch screen would allow you to hug them? It is easy to see why parents might be confused and some genetic counselors feel that 75% of their patients may think that NIPS is diagnostic. Yes, the labs also offer comparison to other screens, information about the conditions being screened for, links to disability focused websites, and acknowledge the role of diagnostic testing. But information does not sell products; images and impressions do.
NIPS is a pretty good screening tool that can help patients decide if they want to proceed to diagnostic testing such as amniocentesis or CVS. However, the first step in the process of considering any testing should be a soul-searching and difficult discussion between parents and with their care providers about views on disability, parenthood, expectations for their children, and beliefs about pregnancy termination (I can’t prove it, but I am pretty sure that discussion is not taking place anywhere near as frequently as it should). For parents who feel it is important to know the chromosomal status of their baby, the next step is to outline the pros and cons of screening tests, emphasizing that a screen only provides a probability that a child may have a particular chromosomal disorder. The risk estimate provided by the screening test may help parents decide if they wish to undergo diagnostic testing.
One might counter that labs are commercial entities engaging in good old American advertising, which everybody knows is not exactly a strictly honest business. But prenatal screening is not like trying to sell Coke vs. Pepsi or Ford vs. Toyota or Chia Pet vs., well, whatever it is that Chia Pets are in competition with. We are talking about babies, our deepest hopes and dreams, and the core values that define our humanity. This demands a higher standard and this is where genetic counselors need to work with their laboratory employers to elevate the discussion.
* Missing from much of the professional discussion about NIPS has been the viewpoint of people with disabilities, their families, and their advocates. As Rachel Adams points out, the Down syndrome community in particular might feel particularly targeted by a test named Maternit21 – but that thorny topic is for another day.