Tag Archives: prenatal screening

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.

 

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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.

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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 InformaSeqTM 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 VerifiTM 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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Guest Post: NIPS And The Threat To Informed Decision Making

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 genetic counseling.

A few months ago, I reached out to the DNA Exchange readership and called for more truth in advertising by the Noninvasive Prenatal Screening companies regarding the accuracy of test results. I recently returned from the National Society of Genetic Counselors meeting where I had the opportunity to survey the marketing and patient materials from labs offering NIPS and to learn about the experiences of my fellow genetic counselors with these new tests.

Not surprisingly, in this dynamic and rapidly evolving field, all of the companies have updated their materials. Some brochures proudly acknowledge how quickly this testing is being integrated into clinical use. It feels like we are being patted on the back for adopting this new test quickly and without question.

I remain very concerned about the misleading claims in the marketing materials aimed at providers and in the patient directed brochures. It is easy to see how the language of the brochures could lead healthcare providers and patients to conclude that these tests are diagnostic or near-diagnostic. These quotes from the materials illustrate my point:

“Definite, informative results.”

“Positive or negative results.  Never maybe.”

“No confusion.  Just simple, clear results.”

To my knowledge, there are no new large studies to dispel my concerns about the positive predictive value of NIPS. Depending on the prior probability, a significant portion of positive results may be false positives– especially with rarer conditions such as Trisomy 18 and Trisomy 13. And because these technologies have been rapidly integrated into clinical practice based on limited research, we do not have robust outcome data to see how false positive and false negative data are playing out in clinical practice.

Since most NIPS testing is done outside of a clinical research protocol, the labs that choose to put resources into follow-up are at the mercy of the providers to share that outcomes information.  Even in the best scenarios, voluntarily reported outcome data are not likely to tell the whole story. I spoke with a testing company representative regarding a poster presented at ACMG last year which based its false positive and false negative results on ad hoc feedback. When I inquired about the meaning of ad hoc feedback, it was explained to me that the company didn’t have the resources to track outcomes so were relying on providers to let them know if the testing results were incorrect. Of course, if a patient terminates her pregnancy based on a false positive test result, nobody will know that the NIPS result was incorrect.

Don’t think a patient would terminate based on NIPS alone? We all hope that women who receive adequate counseling about the limitations of the testing would confirm results with a diagnostic test, but this is not always the case. At a presentation during the recent NSGC Annual Education Conference, one lab referenced preliminary data showing some patients are terminating pregnancies without first getting diagnostic testing, and in the absence of ultrasound findings. While this tracking has some limitations, this lab should be applauded for investing resources in tracking outcomes data and for sharing these data with genetic counselors. Hopefully we will see it published soon and other labs will follow suit.

This situation of patients making reproductive decisions based only on NIPS results may be particularly problematic in communities that don’t have ready access to genetic counseling and/or maternal fetal medicine services.

Imagine this scenario:  a 35-year-old woman living in small town, USA who has limited access to abortion services beyond the first trimester, receives a positive result for Trisomy 13. Based on positive predictive values calculations, there is an 8% chance that her “positive” result is a true positive. But, the patient – and her doctor – may think the probability is much higher, maybe even close to 100%, based on the reporting practices of the labs, which may say “Aneuploidy detected” or “Positive” for Trisomy 13. This does not support informed reproductive decisions.

This patient has 3 options:

  1.  Wait for an appointment at a high risk referral center, at some distance from her home to undergo diagnostic testing. This may limit her reproductive options by delaying time to diagnosis (the later a pregnancy termination occurs, the more expensive it is, and pregnancy termination outside of the first trimester is often not available in many smaller communities).
  2. Seek out pregnancy termination options in her local community based on the NIPS results alone – knowing that she is up against a gestational age ticking clock.
  3. Decline further testing and continue the pregnancy.

If the patient feels that she would not want to continue a pregnancy given a Trisomy 13 diagnosis, and she understands the limitations of the testing, I would imagine that she likely would feel it was worth the wait and the travel for diagnostic testing. However, given the emphasis on the accuracy of NIPS based on the lab reports, and the misconception by OB providers that this testing is “nearly diagnostic”, it is easy to imagine a scenario where she may elect to have a termination based on NIPS alone.

Based on an aggregate of data from the NIPS companies from the first quarter of 2013, one health economist estimates that NIPS is utilized by 40% of the high-risk population in the US, and this number is growing rapidly. So while the patients you see in your genetic counseling practice may be very informed about the limitations of the testing given your expert counsel, this statistic suggests that most NIPS is probably taking place outside of our offices.

We must continue the conversation about how NIPS is marketed and used in prenatal care. While the advantages to a more sensitive screening test are obvious (e.g. fewer women needing to undergo diagnostic testing), we must recognize the largely undisclosed limitations and dangers. Without adequate counseling, patients are being harmed by the misleading claims about the accuracy

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