[HN Gopher] When they warn of rare disorders, these prenatal tes... ___________________________________________________________________ When they warn of rare disorders, these prenatal tests are usually wrong Author : phsource Score : 85 points Date : 2022-01-02 17:49 UTC (5 hours ago) (HTM) web link (www.nytimes.com) (TXT) w3m dump (www.nytimes.com) | gwern wrote: | This article is a confused mess. It's something of a Gish gallop | in conflating all the different issues they could come up with, | while leaving out all the necessary vocabulary (C-f "Bayes" | "posterior" "decision theory" [Phrase not found]) making it | almost impossible to consider each issue in adequate detail. | | It mixes up poor communication (reporting false-positive/negative | rates as if posterior probabilities, & exaggerated confidence | thereof), arbitrary-seeming decision thresholds (but their | hyperventilating over '85% wrong' notwithstanding, many are | probably too conservative, if anything, given how devastating | many of these problems are, there should be _more_ false | positives to trigger additional testing, not less), costs of | testing (sure why not but little is presented), tests which they | claim just bad and uninformative (developed based on far too | little _n_, certainly possible), implicit calls for the FDA to Do | Something and ban the tests (not an iota of cost-benefit | considered nor any self-reflection about whether we want the FDA | involved in anything at all these days)... Sometimes in the same | paragraph. | | Plenty of valid stuff could be written about each issue, but | they'd have to be at least 4 different articles of equivalent | length to shed more light than heat. | creata wrote: | > implicit calls for the FDA to Do Something and ban the tests | | Not that you're necessarily wrong, but how did you get that | from the article? It didn't seem to me like they wanted a ban. | mcguire wrote: | So you are saying the testing companies in the article _aren | 't_ fraudulently claiming much more effective tests than they | are providing? | jrockway wrote: | Specificity and sensitivity are two dimensions that you can | measure tests in. You can claim your test is 99% accurate if | you mean that "if the test says you don't have the disease, | there is a 99% chance that you don't have the disease". That | same test can still be 85% wrong if it says you DO have the | disease, though. | | I doubt that hyping one side of this equation is fraud. | Pushing the error in this direction seems like a good idea, | anyway. If you have some weird illness, and the test comes | back as a false positive, at least you'll continue to explore | that possibility for a while. If it comes back as a false | negative, then you'll spend a ton of time exploring | alternatives which will be true negatives. Probably | infuriating. | | https://en.wikipedia.org/wiki/Sensitivity_and_specificity | bscphil wrote: | They even missed "base rate", which is the way I usually see | this explained to ordinary people without stats backgrounds. | Really disappointing. | SpicyLemonZest wrote: | They don't use that specific term, but the Down syndrome | infographic does a pretty solid job at explaining the base | rate issue. | hn_throwaway_99 wrote: | > implicit calls for the FDA to Do Something and ban the tests | (not an iota of cost-benefit considered nor any self-reflection | about whether we want the FDA involved in anything at all these | days)... | | This is true in so many areas of journalism but lately seems | especially egregious in the NYT. And I don't really blame them, | as the incentives for any individual reporter are just too | great - having the government make a major policy change based | on your article is basically the brass ring for an | investigative reporter. | | I basically can only use these types of articles as a jumping | off point for my own research, as I usually find the moralizing | conclusion the article comes to as unsupported. | nohuck13 wrote: | "the incentives for any individual reporter are just too | great - having the government make a major policy change | based on your article is basically the brass ring for an | investigative reporter" | | Yep, this is the framing I came here looking for. | | Investigative journalists live in the same asymmetrically- | incentivized world as social science researchers. If the | reporter had looked into the phenomenon and concluded "yeah, | boring technical logic pretty much works as expected here" | then there's no story. | csee wrote: | > "The chance of breast cancer is so low, so why are you doing | it? I think it's purely a marketing thing." | | This mindset is ingrained in every doctor I speak to, but I think | it's just so wrong. | | Take DiGeorge syndrome. You have a 1/4000 chance of having it, | and the test carries an 81% chance of a false positive. The above | doctor calls this "marketing"? Foolishness. That's an incredibly | useful test. The downside is small, and the upside is | asymmetrically large. | | We need far, far better screening for all sorts of things. Adult | cancer and heart screens once a year, prenatal screening, and on. | We do a good job with breast and prostate screens, but for rarer | conditions our current approach of waiting for the disease to be | symptomatic makes no sense. Part of that will be driving the cost | down. There is so much market need for a legitimate version of | Theranos and I'm glad there are some companies working on these | things. | lostlogin wrote: | > We do a good job with breast and prostate screens | | Do we? Unless I'm missing something, breast cancer is a huge | killer and PSA tests are deeply imperfect. I am very much not | expert in these areas. | [deleted] | dougmwne wrote: | Wow, what an embarrassing mess. Front page feature of bad | statistics and bad medicine. | sklargh wrote: | I recall a period in the early 2000s when unindicated whole-body | CAT-scans were being advertised on television. | | That got knocked down pretty quickly but wow a lot of folks | picked up a big chunk of their lifetime radiation allowance | because of that. | | These tests seem to operate under a similar model, disregard the | risks of unnecessary testing in return for information of limited | utility that may cause material harm. | bdzr wrote: | I think you're conflating "these tests cause harm" e.g. | radiation and "the information gleaned from these tests could | cause the patient to make poor decisions". Having a regulatory | body make this value judgement for people has quite a bit of | disadvantages. See "DON'T TRY THIS AT HOME: THE FDA'S | RESTRICTIVE REGULATION OF HOME-TESTING DEVICES" https://scholar | ship.law.duke.edu/cgi/viewcontent.cgi?article.... | Enginerrrd wrote: | This isn't really a fair criticism. I could be wrong, but I | believe your comment reflects a bit of naivete about the | current state of evidence-based medicine. | | To evaluate the value of performing a diagnostic test as an | intervention, you DO have to look at final actual patient | outcomes at an appropriate end target which includes sending | people unnecessarily down different treatment paths, | including additional testing with additional risks. And most | importantly is that, in fact, mere knowledge of diagnostic | results has been PROVEN to cause harm in many scenarios. | | Now... if a patient WANTS that test, I think it should be | available. But whether or not it should be performed | routinely without prompting is an appropriate question for | regulatory bodies. | sjckciodjcr wrote: | This article seems a bit deceptive. We are going through NIPT | soon and our doctor went over false positive and false negative | rates for the common screens. Our doctor has pointed out some of | the screens (esp for rare conditions) are not that accurate. The | only procedure with high accuracy, amniocentesis, has a slight | risk of miscarriage (our provider quoted 0.3% ) so its still | statistically better to take NIPT and then only consider | amniocentesis with a positive result since there is no risk from | NIPT. | | You are supposed to treat a positive on NIPT as "there's a chance | your baby has this, need a more accurate procedure to confirm". | | It sounds like their ob gyn wasn't able to explain results to | them or they didn't understand the probabilities. To be fair our | provider didn't even suggest tests for the disorders in the | article, probably because of the false positive rates and rarity. | Sounds like these extra screens shouldn't be offered. | SpicyLemonZest wrote: | "These extra screens shouldn't be offered" seems like exactly | the point the article is trying to make. | [deleted] | tmnstr85 wrote: | My 2nd daughter was flagged during our 20 week for something | having to do with the way her skull was forming and they wanted | to do a series of genetic test. They charged us through the wazoo | and everything came back negative. She arrived 3.5 weeks early | and contracted bacterial meningitis shortly after birth. We found | her code blue in the crib. She ended up having a bilateral | craniotomy to relieve the empyema that had formed. CP, CVI, | global TBI - every day is hell on earth. This was 2019, so the | nightmare of the last few years started early for our family. | We've had a number of medical professionals drop hints at the | fact there might be something wrong from a rare disorder | perspective but we're in a league of our own and that is | hindsight - the damage and trauma are non-stop. Anyone trying to | shickle a few dollars from the medical system to provide "pre- | natal diagnosis" without sound science - they can come burn in | the same hell I live in every day. | jasonhansel wrote: | IMHO, some of those criticizing the article for failing to | understand statistics are missing the point. | | The point is that people who get a "positive" result on these | tests are often put through terrifying levels of anxiety when | there is no actual problem; this anxiety is often exacerbated | because they aren't informed of the false positive rate. This | clearly has a harmful emotional effect on people, and explaining | the false positives in Bayesian terms, or reframing it in terms | of sensitivity and specificity, doesn't undo that damage. | | That potential harm needs to be explained to patients, and it | needs to be weighed carefully against the potential benefits of | the test (as is done for PSA tests for prostate cancer, which | also have a high false positive rate). Given that potential for | harm, it's not unreasonable to ask that these tests be more | tightly regulated. | | To quote the OP: | | > In interviews, 14 patients who got false positives said the | experience was agonizing. They recalled frantically researching | conditions they'd never heard of, followed by sleepless nights | and days hiding their bulging bellies from friends. Eight said | they never received any information about the possibility of a | false positive, and five recalled that their doctor treated the | test results as definitive. | | (Edit: clarified) | midjji wrote: | If you get a positive for a horrid cancer with a 90 percent | false positives you should be afraid. Its lunacy for tests to | be regulated beyond requiring rough false positive false | negative rates, and if anything smacks of "I dont understand | statistics and therefore have to protect my children from | understanding statistics." The article is most likely written | by some anti abortion idiot. | don-code wrote: | I am not a parent, but the criticism of the article appears to be | around a misunderstanding of statistics, or at least how to apply | them. While I agree that criticism is completely correct, it | overlooks the human nature of the people receiving the tests. At | an already-stressful point in someone's life, it seems almost | like bad bedside manner for the medical community, even if in an | automated fashion, to tell people that there might be a | complication looming. | | This _does_, however, seem like a framing issue, more than a | utility issue. If the tests are 100% accurate at detecting true | positives, they're a great aid. But rather than framing the tests | as a be-all, end-all source for information, why not frame them | as "a test that suggests whether or not you should get other | tests"? That simple wording change would save a great deal of | added stress on someone starting or growing a family. | isoprophlex wrote: | I totally agree with this. Managing perceptions and | expectations is super important here. | | Having been on the receiving end of a false positive, I'd still | do the test again for a hypothetical future pregnancy. Even | though it was hell for a couple of days. | divbzero wrote: | Isn't that often true with screens in general? The threshold | often allows a good number of false positives in order to | minimize false negatives. The goal is to know when to seek | further diagnostics. Communicating that to patients can be a | challenge but it doesn't mean the screens were designed | incorrectly. | halpert wrote: | How did this article, written by someone who clearly lacks an | understanding of basic statistics, make it into the Upshot? They | try to make it seem like the test is wrong 85% of the time, but | that's not necessarily the case. All we know from the article is | that 85 / 100 positive results are false positives, which means | the test could actually be quite accurate. If the test correctly | identifies 100% of real cases, then that sounds like an excellent | test. Just as an example, if 1/4000 people have the disease, and | the test identifies 100% of these cases, then around 0.14% of | test takers will get a false positive. | mcguire wrote: | Would a test that reported 100% positive similarly be "quite | accurate"? It would catch _all_ true positives, right? | ellisv wrote: | I disagree. It is clear from the title, "When They Warn of Rare | Disorders, These Prenatal Tests Are Usually Wrong", and the | lead that they're focusing on false positives. | halpert wrote: | It's true they are focusing on false positives, but the | authors are using the ratio of false positives to true | positives to paint a picture that the tests are inaccurate, | when in reality the tests are accurate. What this article is | looking at is called the "sensitivity" of a test: | https://en.wikipedia.org/wiki/Sensitivity_and_specificity | adjkant wrote: | While the author may not be well versed or focusing on the | stats side, you're missing the human side here I think. | | > the tests are inaccurate, when in reality the tests are | accurate | | If the test make someone consider terminating a pregnancy | or even considering it, that's a lot of pain. So for that | human, the test is failing its purpose potentially, | depending on the value calculation of terminating a viable | pregnancy vs the severity of the issue if it comes to term. | | For a human, accuracy as you defined it means little to | nothing. Usefulness and helpfulness are far better metrics, | and such a high false positive rate is clearly causing | issues in respect to those, which is what the article is | highlighting. | halpert wrote: | Or maybe you're missing the human side of having a child | born with a serious genetic defect? | mcguire wrote: | Is it better to terminate 85 pregnancies which do not | have a serious defect in order to catch 15 which do? At | what point is it not better to terminate 100% of | pregnancies? | loeg wrote: | > Is it better to terminate 85 pregnancies which do not | have a serious defect in order to catch 15 which do? | | Yes, it's absolutely better to do that. Of course, the | actual ratio is much better than that because we do | follow-up tests after the screen. | paulryanrogers wrote: | > At what point is it not better to terminate 100% of | pregnancies? | | Everyone should decide for themselves. Having seen the | long term consequences I would rather err on the side of | caution, even if it were difficult to become pregnant. | | Such diseases are often incurable and significantly | degrade the quality of life of not only the person to be | born but the whole immediate family. At least in the US | the there isn't enough social safety net or support too | offset the crushing costs. | andreilys wrote: | _Usefulness and helpfulness are far better metrics, and | such a high false positive rate is clearly causing issues | in respect to those_ | | How exactly do you plan on codifying usefulness and | helpfulness? | | A high false positive rate is not necessarily a bad thing | and may instead be the catalyst for additional tests to | confirm the first one. The tests accuracy may actually be | 100%, which is great because it avoids a child being born | with a fatal genetic disease. Would you prefer a high | false negative rate that misses these diseases instead? | mnw21cam wrote: | No, the article isn't talking about sensitivity. We don't | actually know what the sensitivity is from the data the | article gives us. We are told that lots of people were | screened and a small number had a positive result, of which | a proportion were actually positive. You can't calculate | sensitivity from that because you don't know how many | actually positive cases were missed. | | This article is talking about precision, which is the | proportion of positive results that are true. And it's okay | for precision to be awful, especially when the condition is | so rare. But it's only okay if the result is communicated | alongside a statement saying what the precision is, which | it seems these were not. | halpert wrote: | Yes you are correct. | wizee wrote: | The issue is that the tests portray themselves as being | accurate (in the sense of low false positive rates), and | portray the result as "your baby has XYZ rare syndrome" | instead of "your baby has a 15% change of having XYZ rare | syndrome". If the test providers stated the false positive | rate for their results more clearly, parents would be in a | better position to make informed decisions. | rflrob wrote: | The larger issue as I see it is that the medical system | around these screenings are not well versed in the | statistics and able to communicate that to patients. | "Eight [patients] said they never received any | information about the possibility of a false positive, | and five recalled that their doctor treated the test | results as definitive." It's hard to know what happened | in the room when the doctor spoke with them or what was | on those particular patients tests, and that's (one | hopes) the worst medical news those people will receive | for a long time so listening comprehension is | understandably impaired, but there needs to someone | available who can help them interpret, even days or weeks | later, and these people were let down by the entire | system, not just the test manufacturers. | ramraj07 wrote: | Did they use the word accurate? You used the word accurate | and then you yourself are going on a tirade about how | that's not correct? | | It's clear the article is talking about why sensitivity is | important in layman's terms and while it could use better | writing it's a real problem in diagnostics. This is why you | don't ask men to take a pregnancy test to check for | prostrate cancer. It is accurate but not sensitive. | halpert wrote: | They used the word "wrong". Whether or not they used | wrong to mean inaccurate, or wrong to mean not sensitive | is up to the reader. | SpicyLemonZest wrote: | Their infographics convince me that they understand the | statistics. But one of the key issues here is that the | statistics are radically counterintuitive in a way that most | people _don 't_ understand - the patients, the testing | companies, and even some medical staff all incorrectly believe | that a positive test for a rare condition means you probably | have the condition. | halpert wrote: | Their graphics say the tests are "84% wrong." Do you really | feel that's an accurate description? That doesn't feel like | an accurate description to me, and their usage of "wrong" in | this context highlights that they don't understand the | distinction and importance of true positives, false | positives, true negatives, and false negatives when measuring | accuracy. | isoprophlex wrote: | Going through something like this is very VERY stressful. | When you get a negative you immediately forget about it. | When you get a positive you die inside. Speaking from | experience here. | | 84% wrong sounds, to me, as an accurate description. | Experiencing this from the inside out, only the false/true | positive ratio matters. (Given sufficiently low false | negative rates, of course) | | 84% of people whose world is turned upside down are | actually getting a wrong diagnosis. | [deleted] | andreilys wrote: | You're talking about precision (true positive / true | positive + false negative) but that's only one part of | the story. | | There is a real human cost to having a child born with a | rare genetic disease (and I would argue is immensely more | stressful). You can easily adjust the sensitivity to the | test but at the cost of detecting actual true positive | cases. The correct response to receiving a positive is to | do another test to ensure it's not a false positive. | | To say 84% wrong is clickbait and used to elicit a | legislative response (FDA regulation), which will help | the reporters career. | | The actual ratio to tell if something is "wrong" is | accuracy (True positive + true negative) / (true positive | + true negative + false positive + false negative) | mnw21cam wrote: | No, precision is true positive / (true positive + false | positive). | | Your first equation is sensitivity. | fshbbdssbbgdd wrote: | If you get a negative result and then your child is born | with the condition, you won't forget quickly either. | SpicyLemonZest wrote: | I really feel it's an accurate description. If you get a | positive result on the test, there's a 16% chance your | fetus has a 1p36 deletion and an 84% chance they don't. | halpert wrote: | As you said "if you get a positive result". It's true, if | you ignore the 99.9% of the time the test is correct | (true negative result), then you can say the test is 84% | wrong. | SpicyLemonZest wrote: | 84% of people who got a positive test result will end up | telling their family "it's OK, the first test was wrong, | my baby doesn't have a 1p36 deletion after all". The | 99.9% of other people who got true negatives are | important from a test design perspective, because | specificity is closer to the actual levers you can pull | on, but it's not super relevant to the decisionmaking | process of someone who gets a positive result. | andreilys wrote: | Ignoring all the true and false negatives which | themselves are markers of how accurate the test is. | | 16% precision is the correct statement, saying the test | is wrong 84% of the time implies that those getting | negative results might actually have positive results. | robbedpeter wrote: | He framed his statement correctly, limiting his | observation to the condition that the test returned a | positive result. Saying that 84% of positive results are | false is correct if only 16% are true. You'd need to know | false negative rates and base occurrence rates (modified | by whatever other factors are unique to your situation) | to inform the nature of information you get by performing | the test. | treis wrote: | This seems to miss the point entirely. Even for their worst | example the odds of the fetus having it go from 0.005% to 7%. | That's valuable information even if it's not perfect or somewhat | hard to understand. | inglor_cz wrote: | This would be valuable for running some extra tests (possibly | more expensive, but more accurate), but not for, say, decision | to abort the kid, which is what usually "hangs in the air" | after such a test result. | sjckciodjcr wrote: | NIPT is not supposed to be used for termination decisions. A | positive is meant to be "your baby might have this, test | further with amniocentesis". | inglor_cz wrote: | The article in NYT nevertheless states: | | "A 2014 study found that 6 percent of patients who screened | positive obtained an abortion without getting another test | to confirm the result." | | Maybe people aren't informed enough. It is my experience | that some doctors tend to cut conversations short and some | people are shy/insecure enough not to pry answers out of | them. | | In this case, that would be a tragedy, given that | statistically 5 of those 6 aborted fetuses were healthy. | | Edit: I found the following comment in the comment section | of this article, which appears to address the same issue: | | _I am a physician with a PhD in Biomedical Informatics. | Most patients who receive these tests do not see a maternal | fetal medicine doctor or genetic counselor, and no one | actually explains that the tests they are receiving are | "screening" or "diagnostic." Your opinion that this article | does a disservice to patients reflects your unrealistic | assumption that most of the doctors ordering these tests | are actually communicating effectively with patients (or | frankly, even understand the tests themselves). In my | experience, they usually aren't /don't. Articles like this | "fill the gap" on patient education when doctors are unable | to explain math and risk (i.e., most of the time)._ | sjckciodjcr wrote: | That's a tragedy. Maybe there needs to be regulation | requiring results are delivered by genetic counselors | rather than physicians. Or maybe this is willful patient | error. | treis wrote: | That depends on the person though doesn't it? I'm not sure | what I'd do in that situation. But 7% seems awfully bad odds | for painful and debilitating life. | giantg2 wrote: | I guess that depends on the exact scenario. There are | likely people with a variety of conditions who enjoy their | lives vs having not been born. It brings up a seemly | logical contradiction that we terminate fetuses | (potentially viable in some cases) on the assumption that | they don't want that life yet we don't allow people who | want to kill themselves to do so. | rflrob wrote: | There's a lot of sibling comments going on about whether the | value they're looking at is the right one. What the Times is | showing as their headline number is Positive Predictive Value | (True positive/(TP+FP)), which depends on the prevalence in the | population. The "methods section" here is a little vague, but | given the low prevalence I'm willing to accept on face value that | it's basically accurate (i.e. that it's not assuming that the | families getting these tests are not orders of magnitude more | likely to be positive for these diseases). If the test result | truly said one patient's 'daughter had a "greater than 99/100" | probability of being born with Patau syndrome', then that's | concerning, but given the fairly narrow quotes around the number, | I'd suspect that what is _actually_ on the test result is not | inconsistent with the fairly low PPV on these screens. | hprotagonist wrote: | Behold, the curse of Reverend Bayes: | | https://en.wikipedia.org/wiki/Bayes%27_theorem#Drug_testing | inglor_cz wrote: | Interesting. | | We have been undergoing IVF with my wife since 2019. (Covid made | a huge mess of those plans...) One of our embryos tested as a | possible positive (but only slightly) for aneuploidy of one | chromosome. | | The doctor, a veteran of IVF, looked at the results and said "my | experience is that this is either a very small mosaic error, | which tends to be utterly invisible in real life, or a computer | artifact. I have never seen embryos with those borderline results | develop any serious problems later. Things would be different if | the aneuploidy signals were clear, but definitely do not discard | this embryo". | isoprophlex wrote: | Good luck, keep up your hope. I hope things work out for you. | sterlind wrote: | I've heard that in the early days of HIV, the tests were (e.g.) | 95% accurate, and when patients saw their positive results and | the supposed 5% chance it's wrong they'd sometimes kill | themselves. | | They revised the tests so the first test would say Inconclusive | rather than Positive, and ask them to repeat it. This saved some | lives. | | Maybe this a UX failure? Shouldn't the test designers present the | results like this, even to doctors? | adjkant wrote: | Absolutely a UX failure here, one that it seems some doctors | translate for patients while others are left in the dark on. | From the way people are responding on here about the use of | statistics in the article, it's clear that a big portion of the | techo community I think is undervaluing that often UX is far | more important than it is treated. | tambeb wrote: | A tweet about this very article caught my eye yesterday, and I'm | glad HN's taken notice too. | | https://twitter.com/JohnFPfaff/status/1477382805583716353?t=... | | 'For a disease w a 1-in-20,000 risk, a test w a false positive | rate of 1% and a false negative rate of 0%--an insanely accurate | test--would identify 1 correct case and 200 false positives every | time. Or would be wrong 99.5% of the time. | | This isn't "bad tests." This is... baserates.' | Neil44 wrote: | Before my daughter was born I sometimes felt like it was the | doctors job to scare us with every worse case scenario possible. | It was quite stressful and upsetting. | middleclick wrote: | I had rather my doctor be upfront about all possible scenarios | than to be try and nice about them and save possible | information. | kingkawn wrote: | The point of the profession is to find and address bad outcomes | before they happen. | lostlogin wrote: | I'm not certain that perk of parenthood ends at birth. | neonate wrote: | https://archive.is/LEWoE | | http://web.archive.org/web/20220102044133/https://www.nytime... | csours wrote: | Edit: They kind of do this farther down in the article. | | Considering this as a UX challenge - imagine a grid of 10,000 | dots (100x100). | | Draw one box around the base rate - the rate at which you expect | to find the problem in the population. If the base rate is 1%, | then the box is 10x10 = 100 dots. | | Then color in the dots for the test positive rate (not false | positive, just all positive tests) False positives would be the | colored dots outside the box. | | Next to that, put strikes through the dots corresponding to your | expected false negative rate. | taeric wrote: | This is an example of a problem that is so hard to explain. The | vast majority of folks getting these tests will get a true | negative. Such that for most people, this is not an issue. So I | get that it takes effort to make people care. | | That said, I do feel that pulling in abortions to the debate is | specifically to trigger a set of readers. But to what aim? They | have not established that the tests could be better. Just that | when they say yes, they are still not perfect. | siganakis wrote: | My wife and I went through this a couple of years ago, with a 10 | week NIPT calling a rare trisomy (chr 9), which is always fatal | within a few weeks of birth. | | It was absolute hell. The key problem here is the waiting and | uncertainty. You have the NIPT at 10w, but you can't have the | amniocentesis until several weeks later. When that came back | fine, there were questions about whether it was a "mosaic" | meaning only a small proportion of cells are effected. We were | only really in the clear after the 20 week ultrasound. | | That's a lot of weeks to be consumed by wondering about whether | to terminate the pregnancy, or wait it out for more information. | I have a masters in bioinformatics (in genomics!) and my | knowledge of stats and the science was next to useless in the | face of these decisions. | | I know of couples who simply couldn't deal with this uncertainty | and chose to terminate on the basis of this test alone. | | Fortunately for us our child was fine and is a perfectly healthy | 18 month old now, but I wouldn't do the rare trisomy test again. | bjt2n3904 wrote: | So glad to hear that things turned out well for you and your | family. | tinbad wrote: | Having gone through two twin pregnancies (where the odds of | these tests being correct are especially low) we declined all | of them. Anecdotally, I know of several parents who had a | positive test for genetic disorder, went ahead with the | pregnancy anyway and children were perfectly healthy. Until | these tests are close to 100% reliable I don't see the point. | raymondh wrote: | Thank you for sharing this. | subpixel wrote: | Our experience was kicked off by a troublesome ultrasound and | then confirmed by amniocentesis. | | The tragedy of receiving news like this is probably fathomable, | but I think it may be hard to grasp the emotional and | intellectual agony of deciding whether to terminate a pregnancy | based on a set of probabilities. | | It breaks my heart to think that parents face this decision | with erroneous data. ___________________________________________________________________ (page generated 2022-01-02 23:00 UTC)