Tag Archives: prenatal diagnosis

by Robert Resta | January 8, 2022 · 5:25 PM

The Questions We Should Really Be Asking After Reading the NY Times Article About Prenatal cfDNA Screening For Microdeletions

As the genetic counseling world knows all too well, the New York Times recently published a story about prenatal cfDNA screening for chromosomal microdeletion syndromes. The gist of the article is that screening for microdeletions has a high number of false positives that produce significant patient anxiety and, in a very small number of cases, patients have elected to terminate a pregnancy before confirmatory diagnostic testing. The Times piece generated 1100+ comments on its site, including many from genetic counselors and physicians, not to mention vitriolic sturm und drang on various social media.

Clearly the article touched a collective genetic counselor nerve — a lot of the reaction has been more reflexive than reflective. Which is kind of surprising, considering that cfDNA for microdeletions is a so-so screen for a handful of rare conditions that genetic counselors have not widely agreed should be included on these tests.

Most of the criticism centered on the article not always making a clear and consistent technical distinction between a screaming test, er, uh, I mean, a screening test (which cfNDA is) and a diagnostic test (which cfDNA is not). This confusion has been an ongoing problem since the early to mid-1980s when AFP screening for neural tube defects — and maternal anxiety over testing — was first working its way into clinical practice (I remember one of my patients back then referring to AFP as “alpha-fucking protein”). Forty years later, and the anxiety and misunderstanding has not improved much.

Some of those criticisms are fair, particularly when the article describes cfDNA results as being “wrong” or “inaccurate.” To the specialist, the term false positive has a very specific definition,* and hence the source of the reaction to the article. But from a semantics standpoint, doesn’t the word false in false positive imply wrong? You can also think of calling a result “wrong” as an example of the tried and true counseling strategy of reframing, i.e. “Well, Jane, your test result actually says that there is more than an 80-90% chance your baby does not have a microdeletion.”

In my opinion the article otherwise does a decent job of highlighting the statistical complexities of cfDNA. The accompanying Figures are helpful in explaining what is essentially the positive predictive value of the tests. In fact, I think the graphics are better than the explanations and graphics on many of the testing laboratories’ websites. Many of these websites are even guiltier of muddling the differences between screening and diagnostic tests, and labs really should know better. It’s no wonder that patients might be confused and anxious when they read that a test is “highly accurate,” “an alternative to amniocentesis or CVS,” and can be assured of a “healthy baby” when results are normal. To be fair, some of the websites also address the distinctions between screening tests and diagnostic tests, but only if you click down into the rabbit warren of information.

I think most of the criticism by genetic counselors glosses over more important and fundamental questions that should be the focus of critiques of prenatal testing and our reaction to the Times piece (here I am defining prenatal testing as including screening and diagnosis). These critical questions include:

• Should we test for any condition prenatally? This is an ethically and for some a religiously complex question but it underlies all of the subsequent questions.

• If there is broad agreement that prenatal testing should be available, then what is its purpose? Realistically, with a few exceptions, is there any purpose beyond selective termination? While termination is an important option and benefit of the test for some, it’s not a course of action that all parents will choose. Some parents might decide to have prenatal testing for “preparation” but as I have argued elsewhere there is minimal data saying one way or another whether prenatal knowledge of a condition helps babies or their families, medically, emotionally, or developmentally (thought at least one study is beginning to address this shortcoming). If patients are going to be put through the emotional ringer of prenatal testing, we should be able to provide solid data on whether prenatal knowledge of a condition provides benefits in addition to the option of termination.

• What criteria should be used in determining which conditions should be subject to prenatal testing? Even if every genetic condition could be detected prenatally (and we might actually get close to that point one day), it wouldn’t make sense to test for many of them. Clinically rational and ethically acceptable criteria need to be developed to guide the selection of conditions to consider for prenatal testing.

• Who decides which conditions are screen-worthy? As Ilana Löwy and others have noted, commercial labs often spearhead this choice but decisions are reinforced and supported by the medical and genetics communities that order the testing. If no one ordered a test, labs wouldn’t offer it. As Liza Minelli, Joel Grey, and Scarface remind us, money makes the world go around. Are we screening for some conditions primarily because we can screen for them and labs offer it? What about input from patients, the public, multiple medical specialties, ethicists, social scientists, people with disabilities, and others?

• Is widespread screening for rare conditions the best use of laboratory and genetic counseling resources? Follow up of screen positive results consumes a significant amount of genetic counselor time and energy, to say nothing of patients’ anxiety and health care costs. Should these resources be focused on more pressing conditions?

• Many jobs in the genetics sector — labs and clinical providers — are dependent on the existence of genetic testing. Labs make their living off of testing but so do many genetic counselors working in clinics. While genetic counselors are not trying to push testing on patients, many genetic counseling jobs depend on the availability of genetic testing, either helping patients decide whether to have a test or explaining results to them once the testing has been completed. For better and worse, the genetic counseling profession has intimately identified itself with genetic testing. Clinics would employ far fewer prenatal, cancer, cardiogenetics, and other specialty genetic counseling jobs if there were not so many genetic tests. Think about how many clinical positions would evaporate if prenatal testing — or, really, almost any genetic testing — disappeared tomorrow. Some jobs would remain, for sure. But the demand for genetic counseling would likely drop off significantly if fewer tests were available. How much does this conflict of interest influence genetic counselors’ attitudes toward, and willingness to adopt, genetic tests, and how much does it subtly and subconsciously influence some of the strong reaction to the Times article?

• First and foremost, a patient’s decision to undergo — or not — prenatal testing should be preceded by a soul-searching exploration with partners and care providers about what parents want out of their children and addressing parental fears of disability, along with ethical and spiritual reflection. The decision requires more emotional expertise than numerical expertise. Should we be offering tests to all pregnant women that require them to master abstruse statistical knowledge in order to decide about whether to pursue testing? Even in a (unrealistic) world where all pregnant patients meet with a genetic counselor prior to testing and everything was explained in excruciating detail, many patients will misinterpret, forget, and misunderstand most of the technical information about false positives, false negatives, and distinctions between diagnostic tests and screening tests. What is the best way for patients to make medically and emotionally informed decisions? Laboratory website are less than ideal sources of information. Websites are essentially marketing tools, and marketing is antithetical to nondirectiveness. Chatbots alone don’t cut it for this purpose, although they could have an ancillary role.

• What message does it send to people with disabilities, their families, and their advocates if we continually add, seemingly willy-nilly, more and more genetic conditions to the prenatal testing list, especially, as I noted above, if they obtain no tangible benefit from testing? More testing readily begets further routinization of testing. And when you start testing lots of pregnancies for lots of conditions, you start creeping further into eugenic territory.

There are no easy solutions to any of these questions. Some may very well prove to be unanswerable and some parties will remain dissatisfied if we do manage to come up with some answers. It will involve vigorous and at times contentious debates among multiple viewpoints, and lots of people convinced that they are so damned right and why the hell can’t everybody else see that? But that doesn’t mean we shouldn’t be taking on the challenge. We may wind up with less than perfect answers, but they will be better than what we are doing now. The practice of genetic counseling demands it and patients deserve no less.

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*- Another source of confusion here is the distinction between the false positive rate and a false positive result. The false positive rate is the number of pregnancies that do not have a condition but test positive. Thus, a lab can accurately claim that cfDNA for microdeletions has a false positive rate below 1%. You can see why a patient with a positive result might misinterpret that to mean there is over a 99% chance that her baby does indeed have a microdeletion. On the other hand, a false positive result is one specific patient’s test result which incorrectly indicates that a condition is present. Thus a patient who has a positive microdeletion result has an 80-90% chance that her baby does not have a microdeletion. Lord have mercy! You can see why pregnant patients might be confused. Then try to sort through all that while experiencing the joys of hyperemesis, or if you are a non-English speaking immigrant from a village in Central America working through an interpreter, or if you are also trying to figure out at about the same time the meaning of your rubella result, your HIV status, your nuchal thickness scan, and the results of your carrier testing.

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Tagged as cfDNA, Genetic counseling, microdeletions, NIPS, NIPT, NIPT for micro deletions, prenatal diagnosis, prenatal screening, prenatal testing

by Robert Resta | July 6, 2020 · 11:58 AM

Selective Amnesia, Part 3: We Are Judged On Our History

In Part 1 and Part 2 of this three part post, I described the continuity of explicitly eugenic goals in post-WWII genetics as illustrated by some aspects of the history of the American Society of Human Genetics (ASHG). Here I follow these eugenic threads up to the modern day to help us understand the complicated and at times antagonistic relationship between geneticists and people with disabilities, their families, and their advocates. I pick up the story with the introduction of amniocentesis into clinical practice.

It is probably not a historical coincidence that “genetic amniocentesis” began to flourish once safe, legal abortion became available in the US and other countries in the 1960s and 1970s (amniocentesis had been performed for therapeutic reasons and for monitoring fetal lung maturity and Rh incompatible pregnancies for some time prior). In the 1970s, cell culturing techniques and cytogenetic G-banding allowed reliable prenatal detection of fetal karyotypes. Prenatal testing was initially made available to pregnant women who were 35 or older. The story that is told – our collective memory – is that this age cutoff was chosen because at age 35 the probability of an unbalanced karyotype in the fetus was greater than the miscarriage rate of the procedure. In fact, the primary reason that this cutoff was chosen was economic cost-benefit – the cost-savings by preventing births of children with Down syndrome outweighed the cost of the procedure and lab work. Or, as the authors from a 1973 article in The Lancet more bluntly put it:

“We are less certain about the balance and costs [of amniocentesis] at current rates of screening the whole pregnant population. But is a detailed estimate of the costs required? The lifelong care of severely retarded persons is so burdensome in almost every human dimension that no preventive program is likely to outweigh the burden.”

As each new form of prenatal diagnosis was introduced into clinical practice – maternal serum screening for neural tube defects, chorionic villus sampling, ultrasonography – the scope of conditions considered for prenatal screening expanded, as did the number of pregnant women “eligible” for testing. For example, alpha-fetoprotein (AFP) screening was introduced to detect spina bifida and anencephaly and then broadened when it was discovered that low maternal serum AFP was linked to fetal Down syndrome, trisomy 18 and other aneuploidies and genetic conditions. Detection rates continued to rise as additional analytes (e.g. hCG, estriol) were incorporated into testing. Ultrasonography was initially seen as a tool to measure fetal growth, verify viability, and to identify multiple gestations. It soon became a diagnostic and screening tool for detecting neural tube defects, then Down syndrome, and eventually many uncertain, minor, and profound fetal anomalies. Targeted carrier screening for genetic conditions enriched in certain populations such as Tay-Sachs disease among Ashkenazi Jews grew to include ten or twenty conditions, and now covers hundreds of rare genetic conditions, regardless of ancestry.

Up until the 1990s, most studies that tried to measure the success of genetic counseling focused on reproductive decision making and the impact on the incidence of disabilities. Thus, prenatal testing continued the historical thread of the overarching clinical concerns of medical geneticists that the gene pool was unhealthy and that disability was a medical and familial tragedy as well as an economic drain to be avoided. Compared to counseling patients to make the “right” reproductive decisions, prenatal testing was a more direct tool for avoiding disability and its associated costs. You might counter-argue that not all women choose to have an abortion when faced with an abnormal prenatal test result. Although there is wide variability in termination rates when Down syndrome is detected prenatally (<50% t0 >90%), estimates suggest that prenatal screening in the US has resulted in about a 1/3 reduction in the prevalence of Down syndrome. Other studies show that the ultimate effect of carrier screening is to prevent the birth of children with genetic conditions.

This expansion in prenatal testing occurred with minimal input from people with disabilities, their families, or their supporters. Or input from too many others outside of the genetics and obstetrics communities. No careful weighing of ethical and social values, no seeking of diverse viewpoints. Pretty much any time a new test was shown to be clinically valid or an old one was improved, it was incorporated into clinical practice, a trend that accelerated once genetic testing became big business. Offering genetic testing to all pregnant women for a whole bunch of conditions, well, there’s gold in them thar’ hills.

I know that the view from inside the clinic is very different. Women faced with a positive prenatal test result make difficult, highly situated, emotionally difficult decisions that have little to do with concerns about the health of the gene pool or reducing the population frequency of genetic conditions. But the view from outside the clinic yields a different picture, one in which prenatal testing can look like an existential threat. In addition, people with disabilities get no palpable benefit from prenatal screening, and, tellingly, very little research has been done that tries to demonstrate medical or psychological or developmental benefits to prenatal testing. With rare exception, we are not even trying to show that prenatal testing is helpful beyond allowing the option of termination, even if we claim – with little proof – that it can help prepare a family for the birth of a child with a disability. Advertising for prenatal tests typically pitch the product as a way of ensuring “healthy babies.”

Bias against people with disabilities is not limited to prenatal clinics. It also manifests in genetics clinics where patients and families come for diagnosis and management of congenital and genetic conditions. What, you say? No way. Medical geneticists and genetic counselors are being helpful. We are figuring out what their medical problems are and helping them manage, adapt to, and live with them. We fight and advocate for them.

Yeah, that’s true and we damn well better be doing that stuff. I never met a genetics professional who wouldn’t charge into Hell for their patients. But. A patient visit to a genetics clinic can feel like entering a wunderkammer, a Cabinet of Curiosities, where they are cataloged for their freakishness and pinned in the glass case of a journal article or clinic note. We put them under a clinical microscope to parse out the ways they are different in excruciating detail – the length and shape of their philtrum, the set of their ears, the distance between their pupils, the gap between the first and second toes. Their DNA is analyzed in nano-fine detail in search of pathogenic variants that set them apart from the rest of us. Their rich family histories are reduced to circles and squares that we blacken and mark with death slashes. In effect, clinicians are (unintentionally) doing everything they can to show how patients are different from the clinicians. Geneticists may not be blatant ableists, but they can unintentionally reinforce systemic ableism.

Even the psychological aspect of genetic counseling – what we like to think makes us the ethical antithesis to eugenics – is historically steeped in prejudice against disability. As the historian Marion Schmidt has demonstrated, the history of psychotherapy around disability is rooted in negative stereotypes. Psychotherapists’ theories were based on the assumption that cognitive and physical disability produces unique psychological disabilities for patients and their families. When psychotherapeutic techniques were incorporated into genetic counseling, it was to help families work through the emotional trauma induced by having a “defective child” so the family could ultimately make “logical choices.” For example, Arthur Falek, the director of the first psychiatric genetics department at Emory University, in a chapter on psychological aspects of genetic counseling in a 1977 genetic counseling text, wrote “lack of guidance and realistic planning in families with genetic disorders can lead to disastrous results.” Or as Steven Targum wrote in a paradigm-shifting 1981 article on psychotherapy in genetic counseling “With the advent of prenatal diagnosis and screening programs to determine carrier status, prospective genetic counseling programs have become a reality. Such counseling may avert much unwanted human suffering. The psychotherapeutic considerations discussed in this paper may be applied to prospective parents who need to anticipate the impact of a defective child on them.”

It’s no wonder that people with disabilities might look at geneticists with a wary eye. Viewed with their lens, we’ve been working to reduce their numbers and label them as disappointments to society and their families, even as we paradoxically advocate for them. Sometimes when we are working to do good we can do bad. It is so deeply rooted in our history and our practice that we have a difficult time seeing it. There are parallels here with White people’s attempts to support Black lives that has often served to reinforce systemic racism. This criticism is difficult for us to accept in much the same way that those who run diversity training programs have found that White people who profess to be non-racist have a hard time accepting that their thoughts, words, and deeds can negatively impact people of color. And, like Blacks in America, people with disabilities have suffered from discrimination in housing, medical care, employment, voting, and education. Laws may grant basic rights to ethnic minorities and people with disabilities, but they still have to fight tooth and nail to get those laws enforced.

I am not claiming to be a spokesperson for people with disabilities. I am not in a position to present their views, which may vey well differ from mine. Rather, I am using a historical narrative to try to understand why some people with disabilities may be ambivalent and distrustful of clinical geneticists and genetic counselors. There have been plenty of articles written about these matters, plenty of speakers at conferences, and course work in training programs. That’s all good, but more concrete actions need to be taken. We could conduct more studies on whether there are benefits to prenatal screening beyond pregnancy termination. We can hold more robust and diverse discussions to develop guidelines for deciding which conditions to incorporate into prenatal and carrier screening that are more measured, respectful, and ethically balanced. We need to teach a more honest assessment of our history. We should understand and respect our past but we shouldn’t honor ethically flawed practices like eugenic sterilization by naming awards after their advocates. When we are criticized we need to react receptively, not defensively. We should be as dedicated to these goals as we are to fighting for racial equality. Amen.

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Tagged as disability community, disability rights, eugenics, Genetic counseling, medical genetics, prenatal diagnosis

by Robert Resta | July 29, 2018 · 2:36 PM

Press Secretaries and Prenatal Diagnosis

The prevailing psychological paradigm views the human mind as two different interacting agencies – the unconscious and the conscious. The influence of the unconscious on the conscious mind began receiving scientific attention in the 19th century, reaching a critical juncture with Sigmund Freud’s deep dive into the murky and lurid waters of the unconscious. While many of Freud’s theories have not stood the test of time, his core concept that our unconscious mind is driven by darker instincts that our conscious mind tries to cover over is still widely accepted. And, in a sort of cosmic joke, it is extraordinarily difficult for us to know our own minds because our brains were shaped by evolution to deceive us into thinking we are good people who are conscientious members of society. We are really good at lying to, and believing, ourselves. I like the imagery employed in Kevin Simler’s and Robin Hanson’s recently published book The Elephant in The Brain that compares the conscious mind to a press secretary that tries to positively portray the less saintly aspects of the unconscious mind. Think of a governmental press secretary who has to explain a leader’s questionable statements and decisions without always being aware of what the leader is saying or doing.

So what does the deep mind and its personal Press Secretary have to do with genetic counseling? Well, a lot actually. In previous posts, I have discussed how the unconscious mind can influence genetic counselors’ perceptions of their conflicts of interest, how the pauses in a conversation between speakers can subliminally communicate meaning, and how I sometimes struggle to not let my darker thoughts insinuate themselves into my interactions with patients. In this posting, I look at the role of the unconscious mind in patients’ decisions to accept an offer of prenatal screening for Down syndrome and in deciding whether to continue a pregnancy in which a fetus has been diagnosed with this condition.

There is a common and deep negative attitude toward people with disabilities, even among their care providers, that sometimes borders on fear. Pick your reasons for this – ego threat, announcing to the world your reproductive unfitness, an assault on your concept of an ideal child and family, selfishness to prevent the loss of how you want your life to play out, rejection of those different from us. Readers more astute than I at probing the unconscious can probably think of others. This negative attitude is the driving engine of the prenatal screening train – given a choice, many people do not want to raise a child who will have significant cognitive or physical impairments. Some of this stems from misunderstanding and misinformation about disability. But decisions are typically based on the darker motives of the unconscious mind, not on information.

Here is where the Press Secretary comes in to play. People prefer not to admit to these less socially acceptable thoughts. Instead, they manufacture very plausible explanations to justify their decisions. Mind you, I am not implying that people are liars, hypocrites, or morally derelict. Rather, the unconscious mind usually rules the roost and leaves it to the Press Secretary to put a positive spin on it. This is how the human mind works, and it is crucial to understanding how patients make difficult and morally ambiguous decisions. It is like a role reversal in the Wizard of Oz.* Professor Marvel, Acclaimed by the Crown Heads of Europe, isn’t behind the curtain. Instead, the flaming, smoking, blustering, self-important gigantic head of The Great and Terrible Oz is back there. Oz doesn’t have the heart or courage to fight the Wicked Witch of the West and manipulates Professor Marvel to impart the task to Dorothy the Small and Meek (and, yes, Toto too). Professor Marvel is a bad wizard trying to pass himself off as a good man.

For example, what I often heard from patients as an underlying reason for a decision to proceed with testing or terminations shifted the focus from darker to more personally and socially acceptable reasons:

“We wouldn’t want our other children to bear the burden of caring for a disabled sibling after we are gone.”
“It would be unfair to our other children if we had to devote so much attention to a disabled sibling.”
“My doctor thinks it is the right thing to do and really wants me to have the test.”
“The world can be cruel to people who are different. I remember how a boy with Down syndrome was mercilessly teased in my neighborhood when I was growing up. I would not want to put my child through that.”
“It would put too much of a strain on our marriage. I know I could deal with it, but it would be devastating to my spouse.”
“I want to take advantage of advances in medical testing and information to make sure my baby is healthy.”

As a counselor, there is nothing to be gained from criticizing any of these as being invalid justifications. Indeed there is a measure of truth to them that provides plausibility. Patients are not concocting nonsense reasons or blatant falsehoods. But they also transform the less desirable urges of the unconscious mind into a message that allows the conscious mind to maintain its self-image of a Good Person and to avoid the negative judgment of family, friends, and social networks. On top of this, a well-oiled medical and economic machinery capitalizes on negative attitudes toward disability and reinforces the idea that prenatal screening is a wise choice for responsible parents.

This also has implications for critics of prenatal testing who claim that if pregnant women better understood the quality of the lives of people with disabilities, then more people would reject prenatal screening. This is true only to an extent. The unconscious mind is not usually persuaded by mere facts and will ignore them, reframe “truth” to make it more compatible with the motives of the unconscious, or filter out the parts that it doesn’t want to hear. Bias against physically and cognitively different people is found in all cultures and over time, though there is variation as to which conditions are the focus of a society’s prejudices and fears. People with albinism have been traditionally well-integrated into Hopi society and often play special roles in ceremonial dances; in parts of Africa they fear for their lives. Education alone is unlikely to alter attitudes. Change will require large-scale cultural shifts in views towards specific disabilities and conditions.

Unless we appreciate how the unconscious mind drives behavior and choices, we will never understand our patients – or ourselves.

– The day after I drafted an early version of this posting, I came across the same allusion to the Wizard of Oz in Leonard Mlodinow’s Subliminal – How Your Unconscious Mind Rules Your Behavior. Incidentally, in L. Frank Baum’s Oz books, Professor Marvel explains that his full name is Oscar Zoroaster Phadrig Isaac Norman Henkle Emmannuel Ambroise Diggs, the acronym of which is OZPINHEAD. In yet one more example of bias towards people with disabilities, he chose his name by using the first two letters of that acronym – Oz – and dropping the “pinhead” part.

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Tagged as Genetic counseling, prenatal diagnosis, unconscious mind

by Robert Resta | November 27, 2017 · 10:44 PM

Imperfect Pregnancies: What Ilana Löwy Has To Tell Us About The History of Prenatal Testing

“It seems to me that all the gentlemen agree, some more explicitly than others, that to abort is a good thing and should be encouraged.”
– from a discussion reported in Early Diagnosis of Human Genetic Defects: Scientific and Ethical Considerations, Maureen Harris (ed). National Institutes of Health, 1970.

I sometimes feel like a lone voice howling in the wind-swept darkness when I argue that any opinion, policy, or analysis of prenatal testing must be rooted in historical context. Often these endeavors are informed by technical aspects of a test, such as sensitivity, specificity, cost, and positive predictive value, sometimes accompanied by vague mumblings about “ethical considerations” and “women’s choices.” But these discussions are inadequate unless they also take into account the historical, social, cultural, and economic factors behind the development, expansion, acceptance, and critiques of genetic testing technologies.

To develop a full understanding of prenatal testing, we need to ask difficult questions with thorny, complicated and uncomfortable answers. What was the impetus for the introduction of prenatal diagnosis in the 1960s and 1970s? Why were researchers studying birth defects, cell culturing techniques, and karyotypes at that particular time? How have changing attitudes toward disability, abortion, and reproductive rights shaped, and been shaped by, prenatal diagnosis? What path does a test follow from being offered to a very small and select percentage of the pregnant population to becoming a routine part of every pregnancy? Why are there regional and historical differences in the acceptance, application, and history of prenatal testing? Why is it nearly impossible to have a discussion about prenatal screening that is not also a discussion about abortion?

Well, I don’t feel so lonely anymore after having read Ilana Löwy’s new book, Imperfect Pregnancies: A History of Birth Defects & Prenatal Diagnosis (Johns Hopkins University Press, 2017). The title pretty much tells you what the book is about, but it is more than just a recitation of discoveries and events. The author, an emerita research fellow at the French National Institute of Health and Medical Research, argues that prenatal testing can best be understood in the context of Michel Foucault’s concept of a dispositif – loosely speaking, the institutions, social factors, laws, regulations, scientific and professional practices that create, maintain, and reinforce a body of knowledge and give it power (no doubt some Foucault scholar will take issue with my description, but you get the general idea). But Löwy’s book is not a high falutin’ study of abstract theories of knowledge. It is concretely embedded in a richly detailed analysis – some of it original and some of it summarizing the work of others – of how we have arrived at the point where prenatal testing, particularly ultrasonography and now NIPT, has become integrated into the routine care of nearly all pregnant women in many Westernized countries.

Let me acknowledge some intellectual conflicts of interest up front: the author cites some postings to The DNA Exchange by me and others, references some of my publications, and thanks me – among many others – in her introductory section. No doubt these small ego strokes influenced my perceptions of the book in ways that I can’t fully recognize.

Imperfect Pregnancies opens with the somewhat artibitrary but reasonable starting point in the late 19th century and the work of obstetricians John Ballantyne and Adolphe Pinard, in Scotland and France respectively, on the nature and causes of birth defects and the medical supervision of pregnancy that they felt was necessary to ensure the delivery of a healthy baby. From there she ties in the history of cytogenetics and karyotyping, congenital malformations and dysmorphology, the emergence of amniocentesis and prenatal ultrasonography in the 1960s and 1970s, the introduction of serum and sonographic screening for Down syndrome in the 1980s and 1990s, and right up to the latest testing technologies of the early 21st century such as comparative genomic arrays and noninvasive prenatal testing (NIPT).

This is not a scolding work that draws a straight historical line from eugenics to prenatal diagnosis. While eugenic criticisms are certainly valid concerns about the potential ramifications of prenatal testing and that is true that the development of prenatal diagnosis was a clear reflection of negative attitudes toward disability, the Eugenics Movement per se was not a driving historical engine behind prenatal testing. Still, Löwy makes it clear that prenatal diagnosis was established in the context of a public health model to permit and passively encourage abortion (as the introductory quote at the start of my posting suggests) of aneuploid or otherwise “defective” fetuses under the justification of allowing parents to have as healthy a baby as possible, and that was maintained by the social, ethical, medical, legal, and economic factors that made this possible (i.e., the dispositif). Pregnant women were enticed by tests that offered reassurance but some were left with the messy situation of what to do when the testing did not come back with normal results and had to make extraordinarily difficult decisions about how to proceed in largely uncharted territory, a situation genetic counselors know all too well. In the words of one researcher, women were forced “to become skilled managers of fetal risk.”

The author brings an international perspective to her narrative, including experiences with prenatal testing in the US, the UK, France, Israel, Brazil, and Scandinavia, among others. Prenatal testing is managed differently in each country according to unique local circumstances and this has an impact on uptake of testing and abortion. For example, in the Netherlands, where a detailed discussion of screening is routinely incorporated into pregnancies largely by midwives in a non-medical setting, the uptake of testing is much lower than in countries where there is less discussion and is physician driven. In Brazil, where abortion for fetal indications is limited to anencephaly, the uptake of NIPT is much greater among upper socio-economic status who have access to safe (if technically illegal) abortion compared to poorer women who do not have such ready access. Laboratory marketing has taken advantage of the social status associated with having the latest medical tests among Brazilian women, especially during pregnancy, to further integrate NIPT into routine care. In places around the world where women are likely to leave the work force and devote themselves full-time to child rearing, the uptake of prenatal testing and abortion is lower than in areas where women continue to work after childbirth.

The limitations of the early technologies are somewhat shocking from the biased perspective of today. When John Edwards analyzed the unbanded karyotype of the first patient with his eponymous syndrome, he thought the underlying cytogenetic abnormality was trisomy 17 rather than trisomy 18 until Klaus Patau (who first described trisomy 13) set him straight. In Riis and Fuchs first reports of prenatal diagnosis of fetal sex among hemophilia carriers in Denmark in 1960, one woman proved to have a female fetus that she miscarried after amniocentesis, went on to have another female fetus that also miscarried after amniocentesis, a third pregnancy that was a male and was aborted, and finally had a fourth pregnancy in which the patient successfully carried the pregnancy to term after a female fetus was correctly identified by amniocentesis (I can envision many prenatal genetic counselors simultaneously nodding and shaking their heads right now). Of the first 20 attempts at identification of fetal sex among hemophilia carriers in Riis and Fuchs series, 17 were successful, two resulted in failure to establish fetal sex, and one female fetus was mistakenly identified as male and the pregnancy was terminated (I can hear many prenatal genetic counselors now saying “Ouch!”).

There are a few areas I think the author leaves largely under-explored. Although she gives thoughtful discussion to genetic counselors, I think she understates their importance in ushering in, shaping, and managing each new prenatal testing technology. We have been the boots on the ground as each test was introduced into clinical practice, more or less left alone with patients to negotiate the complicated medical, ethical, and psychological ramifications of “simple blood tests” and “routine sonograms” gone awry.

In the early sections of the book Löwy details the role that obstetricians played in the historical pathways leading up to prenatal testing. However, there was little mention of the obstetricians who worked closely with clinical geneticists and sometimes became board certified in genetics themselves in the 1970s and 1980s – Mickey Golbus, Larry Karp, Mike Mennuti, and Joe Leigh Simpson, to name a few.

I would also like to have seen fuller discussion of the Professional Liability Alert issued by the American College of Obstetricians and Gynecologists in May of 1985, which stated: It is now imperative that you investigate the availability of these tests in your area and familiarize yourself with the procedure, location, and mechanism of the follow-up tests to screen for neural tube defects. Although to the best of my knowledge no one has ever studied the impact of this Alert on the uptake of maternal serum screening in the US, I know that the immediate impact in my neck of the woods was profound and long-lasting. Most of the obstetrical care providers in the Seattle area suddenly started strongly recommending AFP screening to their patients and it set the tone for the ready acceptance of most other prenatal screening tests that followed over the next 30 years. Although the book briefly mentions obstetricians’ concerns about legal liability, she does not go further down this street and I believe incorrectly attributes it to the AMA’s “concerns.”

But these latter points do not detract from the overall achievements and arguments of Imperfect Pregnancies. If you are a supporter or a critic of prenatal testing, or, like many people, decidedly ambiguous, there is much that you will learn and much that will make you pause and re-examine your own views and knowledge base.

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I am delighted and excited to announce that The DNA Ex’s own Laura Hercher is now also contributing an online column for Genome magazine called GenomeCulture. Read her first installment When Genetics Race Problems Rears Its Ugly Head.

Tony Holzman, now retired from Johns Hopkins and who contributed so much valuable research on the social, ethical, and psychological aspects of genetics, is now a novelist. He has published several novels including Blame, about murder and intrigue in genetics research at the NIH. Tony is now working on publishing his newest novel, The Bethune Murals. The novel is based on the true life story of a physician who was diagnosed with TB and was confined to the Trudeau Sanitarium in the 1920s and who produced a remarkable set of murals on paper used to wrap laundry at the institution. Tony is looking to self published his book through Amazon but needs to get enough votes in an Amazon competition. If you have an Amazon account, you can vote for Tony here.

Is Down Syndrome Disappearing? Well, Not Exactly But….

Iceland has given the world the Eddas, Sigur Rós, Björk, and some magnificent geology. A more ambiguous achievement, though, is suggested by a recent CBS News story that claimed that Down syndrome is disappearing from Iceland as a result of prenatal testing. The claim has been bouncing around the Internet for a few years. The earliest reference I could find was a November, 2015 letter sent to the Office of The United Nations High Commissioner for Human Rights authored by Downpride, an international advocacy group for people with Down syndrome. The letter is an “[a]ppeal to the United Nations to stop discriminatory use of prenatal genetic screening aimed at eradication of people with Down syndrome and other groups.” It was, in my view, an understandable and justifiable reaction to largely non-critical widespread adoption of Noninvasive Prenatal Testing (NIPT) from a community that has good reason to be concerned. Needless to say, it generated a lot of heated reaction. Just Google “Iceland Down syndrome” and you will see what I mean.

Delving into the story was like getting lost in a hall of mirrors; many sites simply referenced each other. But the claim that Down syndrome is disappearing from Iceland and that 100% of pregnancies with Down syndrome in Iceland are terminated turns out to be not quite so straight-forward. While Iceland represents a microcosm of the larger concerns of people with disabilities, their families, and their supporters, it is not necessarily an accurate reflection of the macrocosm of the larger population dynamics of Down syndrome in other countries, particularly the United States.

The ultimate source of the data, according to the Downpride letter, was testimony presented to The Althing, the Icelandic parliament that is the world’s longest existing legislative body. I tried unsuccessfully to find that testimony. I then searched PubMed but found only limited help. So I decided to do my own back-of-the-napkin calculations. I obtained the birth distribution by maternal age in Iceland for 2016, and grouped the ages by quinquennia. The expected frequency of Down syndrome was based on data from 1976, prior to the advent of widespread prenatal diagnosis.

Age Group	# of Births	Exp. Frequency of Down S.	Exp. # of births with Down S.
15-19	72	1/1667	0
20-24	592	1/1587	0.37
25-29	1305	1/1087	1.2
30-34	1218	1/763	1.6
35-39	672	1/248	2.7
40-44	165	1/79	2
45+	10	1/24	0.4
Total	4034	1/488	8.27

Thus, in Iceland in 2016, there were 4034 births. In the absence of prenatal diagnosis and selective termination, 8 or 9 babies with Down syndrome would be born, for a frequency of ~1/450-500 births. I then made the following assumptions, acknowledging that each has some potential error:

Based on a 2016 publication, about 80% of pregnant Icelandic women will choose to undergo prenatal screening
According to Dr. Hulda Hjartardóttir, chief of obstetrics at Iceland’s National University Hospital, among Icelandic woman who have a positive screen, about 25% decline diagnostic testing and continue the pregnancy. Thus, roughly 1/3 of Icelandic pregnant women either do not undergo screening to begin with or decide to continue the pregnancy and not proceed to diagnostic testing if a screening test is positive. The impact of these percentages on Down syndrome frequency depends on the age distribution of those who declined screening or diagnostic testing, but for argument’s sake, I assumed an equal distribution across maternal ages.
100% of women whose pregnancies are diagnosed with Down syndrome will choose to terminate. I could not verify this claim, but I decided to go with the most extreme scenario. This has not been the experience in many countries, where termination rates have been high but not typically 100%.
The CBS News story mentions the Combined Screen, so I assumed this was the standard screening test in Iceland when the claims were made in The Althing. I therefore set the detection rate for Down syndrome to 90%, that is, of all women undergoing screening, about 10% of pregnancies with Down syndrome will be screen normal and would not proceed to termination (some studies suggest that the Combined Screen may have a sensitivity somewhat less than 90% but because about 21% of pregnancies in Iceland occur in women 35 and older, a higher sensitivity – and false positive – rate is expected).

Based on these assumptions and the above table, of the potential 8-9 babies born with Down syndrome, about 2-3 would actually be born because their mothers did not undergo either prenatal screening or diagnostic testing, and another baby with Down syndrome would be born because the Combined Screen would be expected to miss about one case. In other words, the total number of newborns with Down syndrome in Iceland would be expected to drop from 8-9 every year to about 3, maybe 4, per year. These numbers could increase or decrease with many factors, such as changes in fertility rates, maternal age distribution, the sensitivity of screening tests, social trends that influence the choice of abortion, and random fluctuations that occur with any demographic trend especially with the small number of births in Iceland (about that many babies were born last year in the hospital where I work in Seattle). If readers know of empirical data from Iceland to support or refute my estimates, please share it.

Of course, for advocates, every loss of a pregnancy with Down syndrome is serious, no matter how small the number. But these estimates put the concerns in some perspective. Among other things, it is fair to say that most, but not 100%, of pregnancies with Down syndrome are terminated in Iceland, and the birth prevalence of Down syndrome in Iceland is falling considerably but not likely, in my view, to disappear entirely.

I think a more realistic picture of the impact of prenatal screening on Down syndrome, in the US at least, is provided by Brian Skotko and his colleagues Frank Buckley, Jennifer Dever, and Gert de Graaf in a recent publication in the American Journal of Medical Genetics. Over the last few years, they have consistently provided some of the most reliable estimates of the demographics of Down syndrome and the effects of prenatal screening.

According to the de Graaf et al. paper, a detailed look at changes over time in the demographics of Down syndrome in 9 states, the number of people living with Down syndrome has steadily increased since 1950. The two major factors driving that growth have been longer survival due to better medical care along with the unrelenting trend of the last 35-40 years of delayed childbearing. This growth, however, has been partially offset by a loss of births with Down syndrome due to prenatal screening. The loss varies with geographic region, but overall, the prevalence of Down syndrome is roughly 70% of what it would be if prenatal screening were not available. Interestingly, the most growth in the Down syndrome population occurred among Hispanics and Native Americans. So, unlike the near elimination of Tay-Sachs disease in many Ashkenazi Jewish communities, the prevalence of Down syndrome is dropping, but not close to disappearing, at least in the US.

Other factors may affect the Down syndrome birth frequency, such as changes in maternal age distribution, availability of abortion, and access to health insurance. For example, in the highly unlikely event that every woman 35 and older refrained from pregnancy, the birth frequency of Down syndrome in the US and many Western European countries would be reduced by more than 50%. On the other hand, if abortion were to become illegal (not highly unlikely), then presumably the birth frequency of Down syndrome would increase. Limiting access to good medical care (unfortunately also not highly unlikely in the US) could lower the overall prevalence of Down syndrome because of reduced survival.

Current trends suggest that, for the immediate future, prenatal screening will continue to reduce the birth prevalence of Down syndrome. It is becoming increasingly easier for women to undergo prenatal screening and more difficult to just say no. This is due to aggressive marketing by commercial labs of “newer, better, bigger, cheaper” screening tests like NIPT; the dearth of time and resources devoted to unbiased education about Down syndrome and the pros and cons of screening tests; inequitable social distribution of medical resources and social support; and the rarity of long, difficult discussions between pregnant women/couples and their providers about whether they should even enter the prenatal screening cascade to begin with. It also does not help matters that the current US President lacks any moral decency and takes pleasure in mocking people with disabilities.

Although I am a strong supporter of women’s reproductive rights and well-informed, gut-wrenching decisions to terminate a pregnancy, it is becoming increasingly difficult to provide ethical justification for further expansion of prenatal screening, or expanded carrier screening for that matter. This is something that society needs to address but particularly genetic counselors because we are in the thick of it.

As I have previously argued, almost no research has been conducted that has tried to demonstrate whether prenatal screening can improve the medical, social, and emotional lives of people with disabilities and their families. Some women undergo prenatal screening because they think it will prepare them for raising a child with Down syndrome, but we really can’t tell them if screening does help or if it is worth their emotional and psychological investment. Carrying out such research is critical. If we can demonstrate broader benefit of prenatal screening, then we can open up a dialogue with the disability community rather than continue the shouting matches, and offer greater and more equitable justification for NIPT and other screening technologies.

Or we can continue shouting at or dismissing one another.

10 Comments

Filed under Robert Resta

Tagged as Down Syndrome, down syndrome epidemiology, down syndrome Iceland, Down syndrome screening, down syndrome united states, Genetic counseling, genetic counselors, prenatal diagnosis, prenatal screening

by Robert Resta | September 21, 2015 · 11:14 AM

1193 to 4

Prenatal diagnosis of Down syndrome has long presented an ethical dilemma for the genetic counseling profession. As genetic counselors are fond of saying , we strongly support women’s reproductive decisions, including both continuing and terminating pregnancies wherein a fetus has been diagnosed with Down syndrome or other condition. But also in the oath that genetic counselors swear to,* we claim to be strong supporters of the rights and dignity of people with disabilities. The disconnect between these ethical imperatives leaves genetic counselors open to justifiable criticism from people with disabilities, their families, and their advocates. How can we simultaneously support people with disabilities while at the same time participate in a screening program whose primary purpose is to sort out fetuses who have certain disabilities?

The typical response to this criticism is that patients have choices about whether or not to undergo prenatal screening for Down syndrome, and genetic counselors try to be value neutral in supporting patient choices (for the moment leaving aside the economic and social realities that limit women’s choices and that genetic counselors have no control over). One of the purported benefits of prenatal screening for Down syndrome is that it allows couples to prepare for the birth of a child who may have special needs. And as many of my patients’ obstetricians used to say to them, we can be better prepared medically for the baby’s birth. Seem like reasonable points, no?

Well, they do seem like reasonable counterpoints. But this got me thinking – just how much research has been done on the extent to which prenatal diagnosis enhances familial adaptation to a diagnosis of Down syndrome, and how much does it improve the medical and developmental picture for the newborn with Down syndrome? In short, I wanted to know how much benefit people with Down syndrome and their families gain from prenatal diagnosis.

To help answer this question, I performed a PubMed search using these broad terms: Down syndrome, prenatal diagnosis, prenatal screening. I set the parameters to English language articles with abstracts for the ten years prior to September 18, 2015. This produced 1373 articles, 176 of which I eliminated because they were not primarily about prenatal screening for Down syndrome, leaving 1197 articles. I then read the abstract of each article for evidence that the research addressed the benefit of prenatal screening to postnatal adaptation of families or improved medical outcomes for liveborn children with Down syndrome.

1193 articles addressed sensitivity, specificity, assessing test performance, comparison of screening techniques, patient anxiety, ethical critiques both pro and con, program implementation, patient education, economic/cost benefit analysis, circulating placental DNA, maternal serum biochemical analytes, ultrasound markers, psychological responses, termination rates, decision making, etc..

The number of articles that addressed my primary question? Four.

And even this number is a bit of a stretch. Two of the four articles were speculative pieces about how prenatal diagnosis may one day allow options for treatment. These two articles shared a primary author and one article was basically a slight update of the earlier article.

The other two articles reported on the experiences of women who received a prenatal versus a postnatal diagnosis of Down syndrome. One article reported that women had a difficult time with how the diagnosis was delivered whether it was prenatal or postnatal. The other article reported that a majority of women who received a prenatal diagnosis of Down syndrome and continued the pregnancy felt that they would undergo prenatal screening in future pregnancies for emotional preparation.

I recognize the shortcomings of my quick analysis. No doubt I missed a few articles. PubMed search results vary significantly with the search terms and parameters, and I swear sometimes with the phase of the moon (speaking of which, the upcoming eclipse of the Blood Moon/Harvest Moon September 27-28 should be spectacular, though it may affect PubMed searches that are conducted during the event). Abstracts may not accurately convey the research findings. And of course the search does not include articles published in languages other than English or that were published before September, 2005. So if you know of articles that I missed, please point them out in the Comments section below. Heck, do a PubMed search yourself and see what you come up with. Prove me wrong, please.

If we are going to honestly present prenatal screening as a choice, the choices have to be more than Abort or Carry To Term, unless of course we want to make the uncomfortable acknowledgement that the primary purpose of prenatal screening is to avoid the birth of children with Down syndrome. Pregnancy termination is important for many couples and we should support patients in their reproductive decisions whatever their motivations, but we also need to show a wider range of benefits from prenatal screening.

Ten years and not even a handful of published research about the benefits of prenatal screening for people who have the very condition that is being screened for. Come on, we can do better than this. Our patients deserve better. Shame on us.

* – Okay, I admit that I made up the oath part, but it is so ingrained into our core ethos when we are trained that it may as well be the genetic counseling equivalent of the Hippocratic oath.

7 Comments

Filed under Robert Resta

Tagged as benefits of prenatal diagnosis, benefits of prenatal screening, Down Syndrome, ethics, Genetic counseling, prenatal diagnosis, prenatal screening

by laurahercher | September 1, 2015 · 2:34 PM

Ohio seeks to criminalize abortion based on a prenatal diagnosis of Down Syndrome. Can they do that? The answer may be more complicated than you think.

This fall, the Ohio State Legislature will vote on a bill that would make it illegal for a woman to get an abortion if she is terminating the pregnancy because her fetus has Down syndrome. If passed – and it is expected to pass – the bill must be signed by Governor John Kasich, who happens to be running for the Republican nomination for president. That should tell you everything you need to know about the chance of a veto.

Ohio is poised to join North Dakota as the second state to restrict abortion from being used to prevent the birth of a child based on a prenatal diagnosis. North Dakota’s law does not specify Down Syndrome, but makes it a crime to perform an abortion that is sought because of a “genetic anomaly.” You might think this restriction is unconstitutional under Roe v Wade — and you might be right about that – but as of today the North Dakota law remains on the books. Abortion rights advocates considered a challenge, but decided that the law was impossible to enforce, and therefore not worth the time and expense.

Beyond the Orwellian specter of a law that parses women’s motivation — and the perversity of allowing abortion only when a fetus is healthy – these laws demonstrate a deeper truth: anti-abortion activists have taken aim at prenatal diagnosis. Rick Santorum’s attack on amniocentesis in 2012 may have been badly articulated, but ideologically like-minded employers have embraced his call to cut off funds for prenatal testing. Genetic counselors may not feel that prenatal testing and abortion are two sides of the same coin, but it is important to understand that the rest of the world sees a clear and causative relationship between testing and termination.

Geneticists are not fortune tellers – a point we are forced to make frequently – and it is hard to predict what will happen in the courts BUT you have to assume these laws would not survive a legal challenge. If it stands it is hard to imagine a prosecution. How do you prove motivation?

Does that mean it doesn’t matter? A recent Bioethics Forum post noted that “It seems odd to allow prenatal testing for Down syndrome – which the American College of Obstetricians and Gynecologists has recommended should be offered to all pregnant women – and then deny women the opportunity to decide what to do with the information.” This was meant as a criticism of the law, but there’s amore chilling implication. If you want to prevent abortions based on prenatal diagnosis, you can restrict the right to abortion OR you can restrict the right to prenatal diagnosis. One of these things is unconstitutional. What about the other?

There are objections you could raise. Free speech! Yes, but telling your patient about prenatal diagnosis isn’t going to help if her health plan refuses to pay for it. The sacred doctor-patient relationship! Yes, but remember that many states already have laws requiring doctors to read from a script to any woman seeking termination. In some states women seeking abortion are told, by law, that abortions are associated with breast cancer. Are you surprised to hear about this alarming association? That’s because it isn’t true.

If you believe that a fetus is exactly the same thing as a baby – and despite widespread uneasiness with abortion most people do not – then prenatal diagnosis is offensive. One typical and less confrontational approach to this attack is to talk about the value of prenatal diagnosis apart from termination. This feels like safer ground, but I would argue that it is short-sighted. Even if prenatal therapies improve, and there are some promising things in the works, testing will remain a vehicle for giving couples the option of termination, and when we deny that fact we look cagey and defensive. We open ourselves to the same charges of hypocrisy that we throw at anti-abortion advocates who cloak themselves in the language of the women’s rights movements. “We are just empowering women,” they say of mandated anti-abortion scripts. No, you are not. “We are fighting for women’s health,” they say, of regulations that put abortion providers out of business. No, you are not.

We need to be prepared to make the argument for what we do. Carefully and sensitively, but transparently, and without shame. We help families have healthy children and that’s a good thing and not a bad thing. We help people make the choices that are right for them. People in this field know that restrictions on prenatal diagnosis are not empowering. We know who they will end up hurting – the poor the young, the vulnerable – all the usual suspects. Prenatal diagnosis is not going away anytime soon. But keeping it available to everyone is going to take work and vigilance.

Follow me on twitter!

@laurahercher

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Filed under Laura Hercher

Tagged as abortion law, Genetic counseling, prenatal diagnosis, prenatal testing

by Robert Resta | August 17, 2015 · 10:11 PM

Guest Post: Sometimes It’s Okay To Fail

by Lisa Demers and Stephanie Snow

Stephanie Snow, MS, CGC has 11 years of prenatal genetic counseling experience. She worked as a clinical site coordinator and genetic counselor for the FASTER study and as a clinical research coordinator for the NEXT study. Lisa Demers, MS, LGC has 12 years of prenatal genetic counseling experience and currently works with Ariosa Diagnostics as a Medical Science Liaison.

The landscape of prenatal screening is changing. The use of non-invasive prenatal testing (NIPT) in clinical practice is already common and is being adopted quickly by generalist obstetricians and maternal fetal medicine specialists. While the cell-free DNA technology is innovative and the impact on patient care is significant, there is a rising chatter about NIPT failures – the 1-8% (depending on the company) of reports that return without a test result. This is a dual issue – there’s the underlying “annoyance” that NIPT occasionally fails to produce a result, and then there are publications suggesting an association between fetal aneuploidy and test failure. The latter is a conversation for another day.

Although these “no call” results frustrate patients and their doctors, the negativity surrounding these failures is surprising. The concept of a test failing is not new in medicine, and certainly not within prenatal medicine. Increasing rates of maternal obesity are just one reason for limited prenatal surveillance, with one study demonstrating that 41% or less of fetal survey ultrasounds on patients with a BMI of 30 or higher were able to be completed on the first try. When it comes to first trimester measurement of nuchal translucency (NT), the FASTER trial noted an overall 7.5% failure rate, either because of an inability to measure or due to inaccurate measurement. In a review of patients within one clinic, where nearly 50% of patients had a BMI over 25 and 25% had a BMI of 30 or more, 4% of patients had an NT failure on the first attempt and of those who opted for a second attempt, 18% failed. Overall in this population, 2.7% of patients did not achieve a NT measurement.

This is not to say that test failures are necessarily bad. When an NIPT test fails, it is often because quality metrics are in place to ensure proper test performance – just as there are standards for NT measurement which are established by the Fetal Medicine Foundation (FMF) and the Nuchal Translucency Quality Review (NTQR) program. An NT may “fail” because a patient presents for screening outside of the appropriate gestational age requirements or because of suboptimal fetal positioning. The nuchal translucency measurement is critical in obtaining aneuploidy risk assessment when combined with serum biochemistry, and even the slightest over or under estimation dramatically impacts clinical care. Such is the case with NIPT quality metrics. These metrics are in place to ensure appropriate risk assessment for the pregnancy, with the most important of these being fetal fraction. Fetal fraction is greatly affected by maternal weight, with obese women less likely having the required minimum concentration of fetal DNA in circulation. Here again, maternal obesity reduces our ability to accurately assess the well-being of a fetus.

In reality, any test failure rate can be a nuisance to a busy clinic. Having patients return for an additional visit is inconvenient to patient and provider alike. However, there are biological and technical reasons for at least some NIPT tests to fail. The thoughtful provider will consider the various metrics involved with the NIPT options and select one that balances high quality metrics (including fetal fraction) and low rate of technical failures.

3 Comments

Filed under Guest Blogger

Tagged as NIPT, noninvasi, prenatal diagnosis, test failure

by Katie Stoll | May 4, 2015 · 12:24 PM

Guest Post: PPV Puffery? Sizing Up NIPT Statistics

by Katie Stoll and Heidi Lindh

Heidi and Katie are genetic counselors and both work with the newly established charitable nonprofit, the Genetic Support Foundation (twitter @GeneticSupport), geneticsupportfoundation.org.

The importance of the Positive Predictive value (PPV) in interpreting Noninvasive Prenatal Testing (NIPT) results is increasingly on the minds of providers as evidenced by frequent discussions, presentations, and publications on the topic. But what if, in an effort to make their lab look like the best lab, the NIPT PPV was overstated in marketing materials or even on test reports? And what if providers and patients believed this information without question or further investigation?

Until 2014, four labs (Sequenom, Verinata Health/Illumina, Ariosa and Natera) were the only companies in the United States that offered NIPT. Over the past year, we have seen a burgeoning of new labs offering their own branded NIPT tests. In some cases, the 4 original companies act as “pass-through” labs in which the testing is branded and advertised through a secondary lab however the sample is ultimately sent to the primary lab for analysis and interpretation. In other cases, referral labs have brought NIPT testing in-house, developing their own algorithms and reporting, such as the case for the InformaSeq^TM test offered by LabCorp and Integrated Genetics. In a recently published marketing document, Illumina lists 16 laboratory “partners” that all offer a version of the Illumina NIPT. The other primary NIPT labs are also distributing their tests through other labs as well; Quest Diagnostics and the Mayo Clinic have been secondary labs for the Sequenom NIPT (Quest also has their own brand, the “Q-Natal Advanced”and Natera’s NIPT is available through GenPath and ARUP).

The growing number of laboratories that offer some version of NIPT presents a significant challenge for healthcare providers who are struggling to navigate the various testing options to determine what is in the best interest of their patients. The competitive commercial landscape and aggressive marketing of NIPT to both patients and providers can further confound clinical decision-making given the paucity of information available to providers that is not delivered with an angle aimed at selling the test.

NIPT Statistics in Marketing Materials

We have noted that multiple labs offering testing have promoted extraordinarily high positive predictive values (PPVs) in their marketing materials distributed over the past year and on their websites ^ and on laboratory test reports. These tables include information regarding PPV frequently reference data from the Illumina platform and Verifi^TM methodology and a study by Futch et al. as the source.

Performance Data Presented in Marketing Brochures for NIPT
Condition	PPV	NPV	Sensitivity	Specificity
T21	0.994	0.999	>99.9%	99.8%
T18	0.910	0.999	97.4%	99.6%
T13	0.843	0.999	87.5%	>99.9%

These figures (or slight variations thereof) have been observed in the marketing materials for multiple laboratories offering NIPT. These specific statistics were reproduced from an InformaSeq brochure and sample test reports available online.

The PPVs reported in this table – being widely distributed on test reports and as educational information for providers – have NOT been demonstrated by the referenced study by Futch et al. or any published NIPT studies of which we are aware.

Of course, the PPV of a screening test depends on the prevalence of the condition in the population being screened. Using the sensitivity and specificity of testing accompanying these predictive value data in the same brochure, one could only derive PPV of >99% if the prevalence of Down syndrome in the screened population was 25% or 1 in 4 pregnancies, far higher than the a priori risk for the vast majority of women undergoing prenatal screening.

PPV = (sensitivity x prevalence) / ((sensitivity x prevalence) + (1 – specificity)(1 – prevalence))

.994 = (.999x.25)/((.999x.25) + (1-.998)(1-.25)

In contrast, if we utilize performance statistics provided by the laboratories, we calculate a PPV of 33% in a population with a prevalence of 1 in 1,000 (which is similar to the prevalence for women in their 20’s) and a PPV of 83% in a population with a prevalence of 1 in 100 (which is similar to the prevalence in women age 40).

The Futch Factor

The study by Futch and colleagues that is frequently cited in marketing materials for NIPT does not demonstrate the high PPVs that are referenced, although we suspect that these statistics were arrived at through a series of assumptions about the Futch data that we will attempt to outline.

This study reported that in a cohort of 5,974 pregnant women tested, there were 155 positive calls for T21, 66 positive calls for trisomy 18, and 19 positive calls for trisomy 13. In this published report, only a fraction of the positive NIPT results had confirmation of the fetal karyotype, 52/155 cases of Down syndrome (33.5%); 13/66 cases of trisomy 18 (19.7%); and 7/19 cases of trisomy 13 (53.8%). There was 1 case of Trisomy 21 that had a normal NIPT result (false negative result), however negative test results were not methodically followed-up, so the true false negative rate for the screened conditions is unknown.

In analyzing the data presented by Futch et al, for marketing materials to derive PPVs of >99% for Down syndrome, 91% for trisomy 18 and 84% for trisomy 13 would require that all of the positive calls WITHOUT follow-up by karyotype confirmation were true positives.

Outcomes data from Futch et al, 2013 and projected PPVs based on category inclusion or exclusion as true positive.
	T21	T18	T13
NIPT Positive	155	66	19
Confirmed (karyotype or birth outcome)	52	13	7
Discordant (Unexplained NIPT results that do not match karyotype from a source or birth outcome)	1	6	3
No information (laboratory did not obtain any information on outcomes)	22	12	0
Pregnancy loss (miscarriage , demise or termination without karyotype)	7	5	2
Unconfirmed (no karyotype or birth outcome known but history of clinical findings suspicious of aneuploidy such as ultrasound findings or high-risk biochemical screening results )	73	30	7
Total Positive NIPTs where follow-up karyotype not confirmed	102	47	9


High End PPV*	99.4	90.1	84.2
Low end PPV^**	33.5	19.7	36.8

*High end PPV- It appears that marketing material PPVs are considering all categories, including confirmed, no information, pregnancy loss, and unconfirmed to be TRUE positives in determination of PPVs.

**Low end PPV- calculated considering all cases, which were not discordant to be false positive results. A minority of positive NIPT results were confirmed with birth outcome or fetal karyotype information.

Given that Futch et al. did not have confirmed fetal karyotype or birth outcome follow-up for the majority of positive calls, it seems at best unlikely, and at worst impossible, that all of these positive NIPT results were correctly called, rendering claims of such high PPVs in the marketing materials based on this assumption to be unfounded. On the other end of the spectrum, if the PPV was calculated to include the not-karyotyped/no-birth outcome information pregnancies as false positive, the assumed PPVs would be 33.5% for Down syndrome, 19.7% for trisomy 18 and 36.8% for trisomy 13. Since the study does not report follow-up karyotype for the majority of positive test results, the true PPV for these NIPTs test likely lies somewhere in-between the high end PPV and low end PPV, perhaps closer to the 40-45% (for T18 and T21) previously reported in another Illumina sponsored study.

While the PPV of NIPT for Down syndrome, trisomy 18 and trisomy 13 exceeds that of traditional biochemical screening, no studies have demonstrated test performance as high as those presented in many of the PPV/NPV tables that are being provided to healthcare providers in marketing materials and, in some cases, on test reports.

A Call For Truth In Advertising And In Test Reporting

Honest communication about test performance metrics must be available to providers so that they can provide accurate counseling to patients making critical decisions about their pregnancies. While most labs do state that NIPTs are screening tests and that confirmatory testing of positive results is recommended, it is not surprising that providers and patients are having difficulty appreciating the possibility of false positive results when the laboratories are incorrectly reporting positive predictive values that exceed 99%. The consequences of relying on lab-developed materials rather than a careful analysis of the available literature are significant. There are reports of patients terminating pregnancies based on NIPT results alone. It is not surprising that some women choose not to pursue diagnostic testing to confirm abnormal NIPT results given the very high stated predictive value.

It is imperative that we recognize not only the potential benefits of these new technologies but also their risks and limitations. Testing companies are primarily responsible to their shareholders and investors, so information provided by companies about their products is largely aimed at increasing test uptake. Professional societies need to call for independent data and federal funds need to be made available to support independent research related to NIPT. Policies and best practices cannot arise from the industry-influenced studies that are currently available. While some regulatory oversight of marketing materials will likely be necessary, we urge the laboratories to consider their marketing approach and how it is affecting patients and providers. If laboratories want to truly partner with patients and providers, they need to provide accurate and straight-forward information to limit provider liability and likewise, help patients avoid making life-changing decisions based on inaccurate and/or confusing information related to test performance. As a medical profession can we come together and make this change without regulatory oversight? Now that would be a medical breakthrough.

^ – Notably, Counsyl has also recently produced a table that provides more accurate estimates of their NIPT predictive values

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Filed under Guest Blogger

Tagged as NIPS, NIPT, noninvasive prenatal screening, noninvasive prenatal testing, positive predictive value, prenatal diagnosis, prenatal screening

by Katie Stoll | November 2, 2014 · 3:46 PM

Guest Post: NIPS: Microdeletions, Macro Questions

by Katie Stoll

Katie Stoll is a genetic counselor in Washington State. She graduated from the Brandeis University training program in 2003 and since that time has held positions in the areas of prenatal, pediatric and cancer genetics.

At the recent National Society of Genetic Counselors Annual Education Conference in New Orleans, a presentation raised some important questions about noninvasive prenatal screening (NIPS). According to the speaker, a woman with a vanishing twin pregnancy underwent NIPS with an expanded microdeletion panel and the results showed findings “suggestive” of a chromosomal microdeletion syndrome.

The patient underwent amniocentesis with a SNP microarray and the results were normal. In a follow-up call with the NIPS lab, the genetic counselor learned that multiple copy number variants were observed (not originally reported) in the original sample. The lab suggested that these variants could be associated with a malignancy or fibroid tumor (and were of course unlikely to be associated with a microdeletion syndrome in the fetus).

As a result of this genetic counselor’s follow-up phone call and due diligence, the patient underwent an extensive work up for possible cancer, but no explanation was found. NIPS was repeated and this follow-up study was normal.

My first thought in hearing this case was – That poor woman! First a lost twin pregnancy, then concern for a severe condition in her baby, anxiety about the amnio, and worry that she may have Cancer. Although I am not a health economist, my second thought was – Holy Cow! How can our healthcare system afford all of the follow-up testing that may come downstream from these tests? NIPS is promoted as a test that will lessen the need for follow-up procedures such as amniocentesis, but will that remain true as the list of screened conditions increases?

In October 2013 Sequenom expanded their NIPS test to include screening for microdeletion syndromes and Natera followed suit in Spring 2014. Some new companies entering the NIPS market are also advertising screening for microdeletion syndromes.

The addition of microdeletions is a brilliant business strategy for expanding the testing market to include all pregnant women. Even though microdeletions are rare, their incidence—unlike that of Down syndrome –is not linked to maternal age. Women who are currently not offered NIPS because they are not included in the high-risk categories proposed by the American College of Obstetricians and Gynecologists (ACOG) guidelines could now be given a reason to undergo NIPS—even though the predictive ability of the NIPS for rare conditions is less than impressive.

Women who elect the test because of an interest in Down syndrome or because they are eager to learn fetal gender may unknowingly be screened for rare microdeletion syndromes which they know little to nothing about. To add to the complexity, a maternal microdeletion condition may be an incidental finding. In a poster presented at the NSGC meeting this year, Sequenom presented a series of 22q11 deletions detected with their MaterniT21 PLUS test. Included in this report were two mothers who were themselves incidentally diagnosed with 22q11 deletion syndrome. Based on the consent form on the Sequenom website it seems unlikely that these women had any idea such a result may occur.

Where is the evidence to support this expanded screening?

These tests are being performed despite there being no published clinical validation studies. There have been some case reports and proof of concept studies; however given that this testing has been commercially available for over a year now, there is shockingly little published about cell free DNA screening for microdeletions. An abstract from a poster presentation at the ACOG annual meeting in April 2014 evaluated 6 samples (or is it 7? – it is not clear from the abstract) from pregnancies known to be affected with microdeletions and 8 simulated samples. They conclude, “This is the most comprehensive, accurate validation of noninvasive microdeletion detection hitherto… This approach will enable accurate, noninvasive, prenatal population screening for these severe disorders.”

Proof of concept is one thing; proof of clinical validity is another. If we value evidence-based medicine, a sample of six (or seven) affected pregnancies is a long way from being a basis for population screening. Whether population-wide screening for extremely rare disorders is worth paying for is, of course, a question in itself.

But in the unregulated environment of laboratory-developed tests, we adopt first and report out results later. Accompanying this process is a lack of transparency – labs performing NIPS with microdeletions have not made performance statistics publicly available and thus patients and providers have no way of determining the accuracy of microdeletion NIPS. In a webinar hosted by Sequenom , the presenters were asked about the positive predictive value (PPV) of Sequenom’s screen for microdeletions. One speaker replied, “We have calculated them. However, what we would like is essentially to wait a little bit to give you more clinically relevant results. Because so much depends on the fetal fraction of the sample and so on and so forth, so we feel that the more appropriate number to release is after we have done 50,000 samples, how many have we found, how many have we reported back, how many were confirmed, how many were in line with the clinical picture.”

Shouldn’t the accuracy of the test be publicly known before it is run clinically on 50,000 women?

Labs have given us only a glimpse of their performance statistics. I was previously provided information from Natera regarding estimated PPVs for the microdeletions on their panel, but I cannot locate this information anywhere in the public forum. The table I was provided stated a 1/19 PPV (5.3%) for 22q11 with a Fetal Fraction >6% and dropping much lower (to 1/45) with decreased fetal fraction (interesting thread here of multiple women with a 1/19 chance of 22q11 on their NIPS result).

In a letter to the editor, former CMO of Sequenom Allan Bombard and colleagues reported that they had evaluated 264 samples from pregnancies with known microdeletion and microduplications or “enriched genomic mixtures” and report a 100% sensitivity and 99.3% specificity. Applying these statistics to 22q11.2 deletion syndrome (the most common microdeletion syndrome on the panel with an incidence of 1 in 4,000) indicates a PPV of about 0.036 or 3.6% . The overall PPV would be expected to be lower given the very low incidence of the other microdeletions on the panel. At the NSGC meeting this year, Sequenom presented some preliminary data from a series of 120,726 samples screened from October 2013 – July 2014 with test performance that exceeds those estimates. Although they did not have complete follow-up data for positive and negative results, a press release from the company following the NSGC meeting reports “high positive predictive values (estimated combined PPV ranged from 62% to 94%)”.

The limited information available suggests PPVs for microdeletion syndromes fall within a broad range of <3% – >90%. Published peer-reviewed studies are needed to help clarify the PPV associated with this testing so that healthcare providers and patients can make informed decisions about utilizing and interpreting this testing.

About a year and a half ago I published a piece on the DNA Exchange that discussed the importance of PPV in interpreting NIPS results. This was written for an audience of genetic counselors, but the posting is being increasingly used as a venue for patients to share their stories and seek information about their test results. Many patients report considerable anxiety – “the waiting is killing us…we have been devastated for the better part of 3 weeks now” – and some express regret for undergoing this testing at all, “I too wish I would of just done the typical old fashion test so nothing was in the back of my mind and hours of my life would be given back…” Recently, a woman remarked that she did not consent to additional testing for microdeletions and indicates her frustration with not being able to find information about the PPV for this test, “Not only are they essentially experimenting on us…they are not transparent about the potential problems with validity or low PPV.”

As genetic counselors, we are implicated in these companies’ approach. We should be demanding better evidence before leading our patients towards testing that could create this kind of distress. We need to be asking good questions, and we should demand good answers. If we cannot figure out how reliable a screening test is from a thorough review of the literature, I think we really need to ask ourselves if we should be offering it in a clinical setting.

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Filed under Guest Blogger

Tagged as cell-free fetal DNA, cffDNA, microdeletions, NIPS, noninvasive prenatal screening, prenatal diagnosis

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