Some relatively new tests promise to find Down syndrome and other chromosomal conditions very early in pregnancy. They are called Noninvasive Prenatal Screens (NIPS), and have been hailed as the “holy grail” of prenatal tests. Just weeks after a fetus’s heartbeat is audible by doppler, the mother can have her blood drawn to look at something called cell-free fetal DNA. In a now-billion dollar industry, Sequenom (Materni21), Ariosa (Harmony), Natera (Panorama) and Verifi all offer NIPS, promising unprecedented accuracy, better information, and general reassurance. The website for the Materni21 test boasts that the product offers “No confusion. Just simple, clear results.”
A 2012 article in the Atlantic began with this explanation:
“Prenatal diagnosis — the ability to diagnose abnormalities before a baby is born — is undergoing a revolution due to the recent arrival of tests that can accurately detect fetal genetic abnormalities, including Down syndrome, by testing the mother’s blood.”
When I became pregnant again–already having a child with Trisomy 21–I seriously considered this new technology, wondering what it would mean for me to have another baby with a genetic difference. It could mean quite a bit or very little, but at a minimum, getting a definitive diagnosis might change my prenatal care decisions.
When I researched these tests, however, I was shocked at what I found. The idea that NIPS are an amazingly accurate diagnostic tool is simply not true. The reality, I found, is a very troubling mix of public and medical misunderstanding, which may well be rooted, at bottom, in pharmaceutical companies looking to maximize profit by mainstreaming their products.
Myth #1: NIPS is great because it is noninvasive way to get a diagnosis.
Reality: NIPS is called NIPS because it is just that: a screen. (Read the ACMG guidelines here.) The number of false positives and negatives does not make it a reliable diagnostic tool. The current ACOG guidelines recommend that NIPS be followed up with a diagnostic test, either chorionic villus sampling (CVS), or amniocentesis. Both of those tests are invasive and carry a risk of miscarriage. In reality, there is no foolproof way to know whether your baby has a trisomy. Amniocentesis and CVS are very, very reliable. Still, mistakes happen. Bottom line: NIPS can only give you a statistical likelihood that your unborn child carries a limited list of genetic conditions.
Myth #2: NIPS is amazingly accurate.
Reality: NIPS seem to be good at ruling out the existence of a genetic condition, but “positive” tests are more complicated. NIPS accuracy rates really refer to the tests’ statistical sensitivity, which is not what most of us think of when hearing the word “accuracy”. An individual’s chance of truly having a condition after a “positive” result (also called the Positive Predictive Value, or PPV) depends on the incidence in the population at large.
Here is an imaginary example. If a test is 95% accurate at predicting redheads prenatally, how does one know the actual chance of being a readhead after testing positive? Not 95%. One has to know how many redheads there are in general. Say 10% of population of country X has red hair, and we test 200 mothers there. Then we know that 20 fetuses truly have red hair. A 95% accurate test will find 19 of those redheaded babies, and miss one. It will also incorrectly identify 5% of the remaining 180 as having red hair when they actually do not—9 babies. The positive test result group is then made out of 19 truly redheaded babies and 9 not redheaded babies. Any individual baby’s real chance after a positive result (or PPV) of having red hair is really 19/28, or 67%.
Do this again with brunette babies in the same country, with an incidence rate of 40%—80 babies with brunette hair. 76 will test positive, 4 missed. Of the remaining 120 babies, 6 will be incorrectly identified. The chance of a baby who tested positive as a brunette is then 76/82, or 92%. When the incidence rate in the general population goes up, the PPV goes up.
Now, say that one in 1,500 babies in country X have purple hair. Do the math for a 95% accurate test, and you get a PPV of something like 1.25%. That means a mother who tests “positive” for her baby to have purple hair, in this scenario, actually only has a 1.25% chance of delivering a baby with purple hair. When the incidence rate is already low, the PPV is lower.
Same test accuracy rate in each scenario, but very different PPV, because the reality of a “positive” test result depends on how often a condition actually occurs in a given population. (I know, I’m sorry your head hurts, mine did too.)
What does this mean? Unless a mother is already at high likelihood, looking for conditions like aneuploidy (like Down syndrome) or Turner’s syndrome is a lot like trying to find babies with purple hair. NIPS tells us what we already know: Most women are not carrying a baby affected by these genetic conditions. When you’re looking at a condition that only 1 in thousands have, the PPV of NIPS is quite a bit less impressive than the test companies would have us believe. Depending on a woman’s age, a “positive” NIPS result could mean the chances of actually having a baby with Down syndrome could be 50% less. Mark Leach at his blog Down Syndrome Prenatal Testing offers a very good explanation of the statistics in this post. Here is another more general article aimed at explaining the confusing statistics behind medical tests and screens.
Myth #3: My doctor recommends it and understands NIPS better than I do.
Reality: It turns out that doctors, just like the rest of us, are actually not very good at understanding the nuances of statistics. In one study, just 14 out of 61 doctors, hospital staff and medical students could correctly answer a hypothetical statistics question. Certainly, it doesn’t appear that the companies offering NIPS tests are running out to disabuse confused medical professionals of the idea that their tests are not as “accurate” as they seem. Do your own research.
Myth #4: NIPS will analyze the baby’s DNA.
Reality: Actually, the test runs on small fragments of placental DNA in the mother’s bloodstream. In most situations, the fetus and placenta share identical DNA. However rare, placental mosaicism does occur. In that case, a woman could get an incorrect NIPS result. Her placenta may carry a trisomy while the actual baby does not, or vice versa.
Myth #5: NIPS can tell you if you are going to have a healthy baby.
Reality: NIPS can tell you absolutely nothing about the health of your baby. Trisomy 21, for example, results in medical issues for some, and absolutely none for others. In addition, NIPS tells us nothing about the myriad other conditions that a fetus can carry but remain undetected until birth or after.
Myth #6: My test result came back “positive” so it must be correct.
Reality: Materni21 terms its results “positive”, “negative”, or “additional” findings, but in reality, these words appear to be more than a branding tool than medical terminology, akin to how Starbucks calls its smallest drink a “tall” to give the impression of value. Because there is no such thing as a “positive” NIPS result, the use of the word “positive” is actually fairly misleading. See Myth #2.
Fundamentally, I do think that these tests stir up some very serious ethical issues about disability, as well as how our society views pregnancy and birth. Plainly, this technology begs the question: Who gets welcomed into our society, and who must undergo “screening” before even drawing a single breath? Yet, this is the reality of all prenatal testing.
My concern is the power of perception to recreate reality. If these companies are allowed to perpetuate these myths with impunity, then I fear they will become the foundation for actual practice. Perhaps my fear is already reality. How many women have chosen abortion after a NIPS result, who would not have if they had truly understood the statistics? How many women misunderstood these statistics and go through needless anxiety and worry because they’ve had to prepare for a reality that never came to pass? NIPS is very good at “reassuring” mothers that their babies are genetically typical, but does that come at a cost? With every “negative” test, how much stigma compounds against those who actually live with those genetic differences?
Even within the disability community, we seem to have bought the pharmaceutical companies’ advertising ploys, hook, line and sinker. I worry that by perpetuating the companies’ marketing ploys, we are inadvertently creating more room for ethical lapse. The tests are here for good—there is no closing that box, and I see no point in arguing that. We might as well help families get accurate information and strive to point out the inherent anti-disability bias so prevalent in today’s prenatal care practices.
Is NIPS an advancement? For a woman who wants to test for those specific conditions, I do think that NIPS has value over traditional screenings. Is NIPS revolutionary? Only if we pretend it is.
If you have had a negative NIPS experience, or feel that NIPS was incorrectly or misleadingly explained by the company’s marketing material, you can report it here. Prenatal tests fall under the “medical device” category.
Here is a very clear article from Katie Stoll, genetic counselor, explaining the specific statistical issues behind NIPS.
Lettercase offers up-to-date information and materials on prenatal screening and testing for families and medical providers.
Mark Leach is a bioethicist who writes frequently about NIPS on his blog.
If you have found this post after getting a “positive” result for Down syndrome in particular, you can go to the Down Syndrome Diagnosis Network (DSDN) for accurate information and support.
If you have found this post after a Harmony, Verifi, or Materni21 test and are confused, feel free to comment or email. I will try to send you to the appropriate resources.
If you have recently followed the blog, you might not know about Ethan Saylor. He was a man with Down syndrome who went to the movies with a caregiver, had a misunderstanding over wanting to stay in the theater without a second ticket, and ended up dead. He died of asphyxiation; his throat was crushed when three off-duty police men tried to inappropriately remove Saylor from the theater instead of allowing the caregiver to diffuse the situation.
During that time, many people in and out of the disability community were calling for more police training, believing that such training would have altered the course of events for Saylor. I felt deeply ambivalent about the discussions on police training after the Ethan Saylor’s homicide. In fact, I saw some very real examples of how the concept of training turn into something very wrong.
Last week, many in the Down syndrome community became aware of a children’s gym called Surgent’s Elite School of Gymnastics in New Jersey that refused to allow a little boy with Down syndrome to have his fourth birthday party at their facility. When the boy’s mother went to arrange her son’s birthday, she discovered that the gym had a blanket “no special needs” policy.
The New Jersey play gym defended their “no special needs” policy because they claimed they did not have enough training.
Cases like the little boy in New Jersey are downwind casualties of the very flawed logic of training that I saw after Saylor’s death. I won’t go into the myriad reasons that I didn’t think discussing training was appropriate in the immediate aftermath of Saylor’s death, but will say generally that I think it siphoned off valuable energy that should have focused on accountability and discipline. Above all, I worried that the myopic focus on training would bolster the false logic that one needs special training or expertise to interact with a person with a disability.
I think that supporting disability training in all situations, for all reasons, is very dangerous. It subtly creates a believable barrier to understanding and inclusion. If a four-year-old boy can’t even have a birthday party without some kind of specialized staff present, then how could that boy be included in a typical classroom? Play sports? Be in public? Many can easily make this troubling leap in logic.
It is clear that the manager of the gym is not out to be a terrible person. He’s since offered to host the party, which is a step in the right direction. Yet I can’t get behind his insistence on hiring specialized staff to do it. I cannot, for the life of me, imagine what kind of specialized staff would be needed for this situation. I’m sure many are thinking, oh, but maybe the boy wasn’t physically able to do what his similarly aged peers could do. The mother reported that her son had no medical restrictions. I’d hazard a guess that the boy liked and could do the kinds of activities that a birthday party at a gym would entail, or else his mother would not be pursuing the idea at all. I’ve been to plenty of kid’s gyms. Children inevitably have different ability levels, that is simply natural variation, special needs or not. Any decent staff knows how to adjust the activities so that all the children present are comfortable. Don’t mistake me, I can imagine various, specific circumstances in which a child would need some extra support in order to participate in a birthday party at a play gym. But frankly, I can imagine these situations in and out of the special needs realm.
The message, in the meantime, seems clear. Children with special needs cannot be included simply as a matter of course. In fact, it may be safer to exclude them altogether. As an aside, this safety logic was also very prevalent in the aftermath of Saylor’s death; many blamed Saylor’s mother for placing him in the supposedly dangerous situation of being out in public without her presence.
Is it such a big surprise, when some in our own disability community accept that police brutality against their own can be solely addressed with… training? This over-reliance on training sets disability apart in a way that I do not see in any other marginalized community. Imagine the words, “If only he had been trained to deal with black people,” were uttered after a race-related officer shooting. Yet, replace “black people” with “disabled people” and this sort of logic occurs every day in our schools, police departments, government, and every day conversations without enough critical examination.
It isn’t that I don’t think awareness training can be valuable. Sensitivity training for all sorts of groups, for instance, is a good thing. I don’t feel differently about disability training. Mainstream America could stand to learn what disability actually is and isn’t, and that it is a varied and diverse part of human existence. It is an unfortunate fact that many people simply are not exposed to positive and realistic depictions of disability and if training can help bridge that gap, wonderful.
Let’s just be careful. Training can only be a small part of that solution. It is hard to talk about inclusion for the sake of inclusion, accountability and discrimination because they force us to confront basic ideas of good and bad, right and wrong. These conversations are confusing sometimes and can get uncomfortable, but ounce for ounce, the amount of positive potential is much greater there than in simply slapping a training/expertise label onto the problem and walking away.
If I could get in a room with the officers who killed Saylor, I would ask them why they felt that Saylor was so different that the de-escalation techniques they surely already knew were not applicable. I would tell them that if they had dug into the basic training they already had, that Saylor could still be alive today. I’d tell them to approach every person, disability or not, as a unique and precious life.
If I could get in a room with the manager of Surgent’s Elite School of Gymnastics, I would tell him to reconsider his belief that he needs special training to run an inclusive gym. I’d tell him dig into his basic instincts for interacting with children, rather than adopting a blanket policy of exclusion out of fear. I’d tell him to approach every child, special needs or not, as a unique and precious life deserving of inclusion.
I’m still in the weeds.
The days are slipping by like an endless rosary, and I can’t decide whether this circular existence is meditative or torturous. Feeding, playing, cleaning, sleeping, teaching, disciplining, feeding, playing, cleaning, sleeping, feeding…
I get frustrated, because I don’t feel like I’m progressing.
Perspective is slippery. I look at my life now, and think, I wish I could tell my one-child-having-self to relax and stop sweating the little stuff, don’t hover. That person would look back and tell my childless self to enjoy all that flexibility and free time. That person would look back and tell my young, single self to get up and not waste so much damn time. And money. That person would look back and tell my teenage self to stand a little taller and prouder, stop caring so much about what others thought. That person would look back into my childhood, and imagine all the things that could have been, or should have been.
Then, my mind curls back to the present, and I look at my children. If my inner mother squints just right, I can’t tell the difference between my children and myself. What do I do as a parent that is truly about them? Is it really about me, talking to a former self? It is wrong, if I merge and detach from my children so many times a day? Is this progress, or is it just an endless treadmill?
When I watch my children play I’m often surprised by the sheer amount of repetition they do. Stack the block. Knock it down. Stack. Knock. Stack. Knock. Again. Jump over the puddle. Jump in the puddle. Jump over. In. Over. In. Over. Again.
To most adult minds it seems useless. Why go back to where you’ve already been? We trick ourselves into thinking that being in one place, doing one thing, means we have learned all there is to learn. So I get frustrated that my days seem to be filled with the same tasks. I take a deep breath when I have to empty the dishwasher again after breakfast is over. Again.
But children understand something that we adults love to forget. They instinctively go back to the same things over and over again, and their minds catch every tiny difference. So they learn, exactly how far a block can be placed off center before it tumbles. They learn the infinite variations of water droplets on a rainy day. They know that repetition is the doorway to depth. I have to wonder how much I lose by thinking that my past is somewhere only to remember, to put away in a box for safekeeping.
So I’m trying to do the same as my children. I’m trying to walk my past, in their present, whether it seems mundane or not. And when I think back on all my former selves, I can learn again instead of thinking I’ve really moved beyond. That’s progress, right?