My name is Mark W. Leach. 
I am an attorney with a Master’s in Bioethics.
I have presented at international, national, regional, and local conferences for obstetricians, medical geneticists, genetic counselors, bioethicists, and Down syndrome support organizations. I have been published in professional journals, national and local newspapers, and on-line blogs. This blog is a continuation of my efforts to provide perspective and resources for informed decision making for those involved in the administration of prenatal testing for Down syndrome.
I serve in various volunteer capacities for several non-profit organizations devoted to providing education, support, and health care to individuals with Down syndrome and other intellectual and developmental disabilities. I am also the bioethics specialist for the National Center for Prenatal & Postnatal Down Syndrome Resources. All of the views expressed on this blog are entirely my own and should not be attributed to any organization with which I am associated.
I have two kids. My daughter is endowed with Down syndrome and my son is endowed with curly blond hair. We live in my hometown, Louisville, Kentucky. On any holiday weekend and for two weeks each summer, we can be found cruising America’s highways and byways towing our 24’ travel trailer en route to the next NPS site, state park, Bison herd, or roadside attraction and usually seeing a major or minor-league sporting event on some of the evenings.
You can contact me via the comments on this blog and by following me on Twitter.
This is a fantastic site. Thank you. I hope you don’t mind me borrowing your term ‘endowed with Down Syndrome’, it’s so apropos. One of the best friends I have in this world is endowed with Down Syndrome and so very much more!
I heard that phrase first used at a conference in 2007, so feel free to use it as you see fit.
I say my son Knox has Up Syndrome… Because there is nothing down about him.
Hi mark,
Im currently 13 weeks and 5 days pregnant with fraternal twin girls. I did my panorama test at 12 weeks. I just got a call saying my results came back at 99% positive for down syndrome. I am 36 years old. I am confused as i was told that its 99 percent chance but because its twins they calculated that factor and its 70 percent chance. Im sorry i could not comment on the other post pages you had. I would really appreciate your insight. I am overweight and did have high hcg from beggining of pregnancy.
Based on your age, this online calculator computes your chance of the test being a true positive to be 79% if it were a singleton pregnancy. This means the chances the result is a false positive is 21%, if it were a singleton pregnancy. You can learn more about cell free DNA screen results at this link. I would forward that link to your doctor since they are delivering incorrect information about test results. You may also want to ask your provider to ask Natera, the maker of Panorama, what your test results mean since you have twins. Finally, for more information about Down syndrome, here is the link to the recommended information.
Hi Mark. I am 43 years old with no genetic abnormalities in family. My Hcg was 4.33, NT 1.9 at 12 weeks with no notable US markers, calculated my risk at 1 in 9 for DS. This morning my Harmony returned positive results for Trisomy 21 at 16 weeks. I am considering amnio, yet unsure as I will be proceeding with the pregnancy no matter what the result. Appreciate any feedback or calculations you may have. Thank you as your information is a great help at this confusing time.
The online PPV calculator gives PPV based on your age and a positive cfDNA screen result of 97% with the chance of a false positive being 3%. With you saying your intend to continue regardless, professional guidelines include Diagnosis to Delivery as an approved resource for expectant mothers with a prenatal test result for Down syndrome who plan on continuing their pregnancy. This book is available for purchase or download it for free online at this link. Professional guidelines also recognize that talking with a member of a parent support organization can be helpful. You can find an organization in your area by clicking on this link, selecting your state, and then clicking the “Get Connected” tab.
Hi Mark
My name is Sinead. We have the most wonderful daughter who just turned 4 and who happens to have DS. I am now pregnant again and I am 17 weeks. My recent blood tests revealed 1 in 20 chance of a recurrence of DS and so we have opted for the Harmony test which we will do next week. I am 34. Can you tell me if you think this will also show a ‘highly likely’/positive result. My consultant referred me for an amnio but I turned it down as I already had a miscarriage last year and we had an amnio with our daughter. We don’t feel the need for it this time round.
Many thanks
I can’t say what the likelihood of your Harmony coming back screen-positive is, other than with a 1-in-20 chance, that would mean a 5% chance that your pregnancy is positive for Down syndrome and a 95% chance that it’s not. Based on your age, according to this online calculator, a screen-positive Harmony result would mean a 75% chance of it being a true positive and a 25% chance it is a false positive.
I wish you well. My daughter is 16 now. Every age has its wonders, but I recall four fondly.
Hi Mark my daughter and soon in law who are 27, were told today that the child they are expecting has downs…this is the only information they received from this test result….trisomy 21. (Risk)1/870. (Test) 99/100. All other tests were fine….can you please help. She is making herself sick she is so upset…thanks
Anne–none of the tests report a risk score of 99/100, or more accurately, they shouldn’t. I would refer your daughter to the posts here and here and the posts linked within them for her to understand that receiving a screen-positive result still means she has a better than 50% chance that it is a false positive.
Thank you for this site. I am currently going through this nightmare of being told I have a 99% chance of a baby with DS – the results given to me by phone with no PPV given…and no resources. I am scheduled for an NT and then a CVS next week. In the meantime, I’ve been scouring the internet for information. It seems there is a lot of conflicting information about the accuracy of these tests. For now, thank you for providing information that helps to clarify the issues.
Catherine–I’m glad this site has been helpful and will continue to be helpful depending on your further test results. I hope those go well and you receive better information going forward.
I went for the harmony test at 10 weeks and 1 day I had received terrible news that I tested 99% that my baby girl that most likely has down syndrome, I have 2 beautiful healthy kids no history on my side or my husband side . However they told me to go to a specialist first thing was told to me let’s talk about termination! ! I was crying and felt scared he than told me iam gonna secdule you for cvs test mean while took a measurement sono of the baby everything came back perfect . Iam sick to my stomach I want to just hold my baby in august and never let her go what are the chances she is ok , I had all same test with my other 2 kids never had this harmony test with them I have it now at 37 and told my baby most definitely has down syndrome. I keep reading all different things I do t go till Thursday for the cvs, bit when I went for this harmony test my dr also had me on prodestone pills can that maybe have anything to do why I tested postive . Iam scared and so upset please I need some answers . Thank you so much
I’m sorry to hear about your experience of receiving inaccurate information about your Harmony results. Your physician is mistaking Harmony’s marketed sensitivity rating with your positive predictive value. Based on your age, your Harmony result should mean that you likely have around an 80% chance that your daughter has Down syndrome and a 20% chance that the Harmony result is a false positive. The National Society for Genetic Counselors has created a helpful fact sheet on testing like Harmony which you may want to review and provide to your doctor. It further sounds like you were not provided any of the recommended information to accompany a screen-positive result for Down syndrome. The recommended resource to provide mothers is Lettercase’s booklet, which you can access here. The lab that makes Harmony was provided 2,000 copies of the booklet and your doctor can order one for free. (You can also view it online, as well). There are more recommended resources for expectant mothers that can be found at the Prenatal Resources tab. I hope these are helpful to you.
My wife took a cfdna test that tested positive for down syndrome. She then had an Amniocentesis which we got results of the FISH test (we’re still waiting on the full Amnio results) and the results are that the baby is normal. How common is this?
After discussing with others, 2 ppl we know had the same result. One of them said they tested positive on the cfdna for all of their children and the amnio results were that the kids were fine, which was the case with the children.
There’s no way of knowing how often false positives occur since the labs either do not track this information or do not report it.
We received the results of the Amniocentesis and I’m even more confused. The results from that test are that 30 of the 34 cells in the sample tested positive for Turner Syndrome, 3 of the 34 cells were normal and 1 of the 34 cells had an extra Trisomy 21. What does this mean? The baby cannot have Turner syndrome as it is a boy (previous tests confirmed this and the doctor has confirmed this in the ultrasound as his privates can be seen).
So to summarize our cfdna testing showed a slightly elevated level of Trisomy 21. The doctor described it as a slight elevation, but not elevated as much as they normally see with down syndrome. As a result of this we were directed to have an amnio. With the fluid from the amnio they ran a FISH test and a full amnio test. The FISH test results were that the baby is normal. Then we got the full amnio tests results today showing the abnormalities I described in the first paragraph. What is going on in these tests as the results are all over the place and the amnio results aren’t even a possibility (as in you can’t have Turner syndrome in a boy, and if you had these disorders they’d be present in all of the cells, not bits and pieces).
Thank you for replying and I eagerly await your reply to this as well.
There is a form of aneuploidy where an extra chromosome is present in some but not all cells, which is referred to as mosaicism. However, with this being an amnio, this really is a difficult result to understand. I would ask to be counseled by a medical geneticist to interpret the results for you.
We did. They cannot. They say it could mean the baby is normal or it could mean that the baby has down syndrome and the Turner syndrome results baffle them. So after three tests we have no answers and are forced to live with anxiety. After our experiences, I’m very skeptical about the accuracy or benefit of testing.
I at least appreciate their honesty in admitting when they don’t know. I hope that going forward you receive compassionate care and have a healthy delivery.
Mark, thank you so much for your blog. it has helped me understand prenatal testing for Down syndrome much better. I am giving a presentation on Down syndrome later this week which includes prenatal testing. I was wondering if I am able to use the graphics on your blog in my presentation, if I give your blog credit. Thank you.
Just a few graphics, not many.
For you, Eileen, you may use the graphics provided credit is given to the blog. (Any other readers who may wish to use any graphics will need to submit a similar individualized request). I’m glad you found the information here useful. Please share who you are presenting to and I’ll be curious to hear who it went.
Thank you very much, Mark. I am presenting at the National Right to Life convention. I do a workshop on Down syndrome in which I give an overview about Down syndrome in general, prenatal testing/abortion connection, research, legislation, life with a child of Ds, etc.
Regularly, well-meaning advocates will quote the outdated “90%” figure for abortions following prenatal diagnosis. You may find this post helpful on how while the rate is lower than 90%, the actual numbers of selective abortions for Down syndrome have never been higher.
Mark,
Yes, I used to quote that statistc–it is the one that shocked me and drew me into the pro-life movement–and now I understand that it probably isn’t accurate for the U.S.. I mention this in my presentation and also mention the latest study that estimates the overall reduction in the number of Down syndrome births. I also understand how a lower abortion percentage can still mean more babies being aborted because of many more pregnant mothers being tested now and more unborn babies w/Ds being diagnosed). I actually wrote a commentary in our regional paper a few years ago just before the new tests were being implemented with my concern about this very scenario. Thank you for the link; I think I have it in my stack of resources I was reading to prepare for the talk. Again, thank you so much for your work.
Hi Mark,
I am 30 and 15 weeks with my first baby. After a perfect nuchal scan with a visualized nasal bone, my blood serums came back with a risk of 1/93 for downs. Because this number is above the first trimester cutoff of 1/50, my doctor does not believe I need a diagnostic or to speak with a genetic counselor but has instead offered me the Infiniti, which I’ve taken and am now awaiting the results. I am confused as to whether or not I actually tested as high risk, since he said my test was technically negative and why he’d be sounding alarms and yet not allowing me to go directly to a diagnostic. Thanks for your input.
I’m not sure why he advised you the way he did either. Your screen result would place you in the “high risk” category for purposes of being offered additional testing. However, professional guidelines all recognize the need for genetic counseling following a high risk result and for pre-test counseling before taking tests like Inifinit (which I presume is a cell free DNA screen result–here in the United States, “infiniti” is a luxury car brand).
Thanks, Mark. My apologies–I meant the verifi NIPT. My brain has been frazzled the past several days. I called back my doctor’s office and asked if I could be scheduled for a diagnostic and was told to wait for the NIPT results, and the nurse reiterated that my screen was technically negative but that they just want some added reassurance. This is so confusing! And it’s especially hard when no one can explain this algorithm for me. I know that I had high HCG twice the median and low PAPP-A, about half the median, which I guess is a classic pattern for DS. But I have so many questions and wish someone could answer them… As I imagine it is for most women my age, this entire thing came as a shock, especially 2 weeks after a beautiful nuchal scan that me over the moon about my pregnancy. I also am upset that I didn’t get the blood draw until the 12 week scan… from reading so much on it, it seems as though many women do the blood portion well before the scan so that they already have the results and therefore have the option of doing the CVS, which is too late now for me. I’d have to wait for an amnio now. Do you have any idea why the cut off would be 1/50 for the first trimester screening when I am apparently high-risk? How accurate are these predictions? Honestly, I think it’s 50/50. My baby either has down or doesn’t so I’m just incredibly confused by the lack of information they’ve provided me with.
I’ve never been clear on why the cut-offs are set at the ratios that they are. However, having accepted the verifi test, you may want to factor those results into whether to have an amnio, particularly if verifi comes back screen negative. As for CVS, professional guidelines recognize that CVS tests DNA from the same source as tests like verifi. While CVS is considered diagnostic, it does have a greater risk for delivering false positives than an amnio and it has a higher risk for miscarriage. See this post here which can share more information on tests like verifi and links to resources on Down syndrome.
Thanks, Mark. The NIPT came back today negative, or rather “no aneuploidy detected.” I suppose rightly so my doctor is not recommending a diagnostic at this time but they still want me to do the second trimester screening, which I think is more so for spina bifida in this case. Honestly, I think I’m done with all future screenings. It is a lot easier to manage the fear of the unknown with a baby in your arms. Thanks for all of the info.
I think you’re right as to why they want you to do the second trimester screening. In the case of spina bifida, it can sometimes be seen on ultrasound, depending on the kind and severity. I like your second to last line and is a truth that we experienced with our daughter.
Hi Mark, I received a prenatal diagnosis while at Disney World 16 years ago. It was the triple screen fret with uncertainties. We did the amnio and yes it was positive. It was a scary time and we ended up having our son. He started high school this fall and is the most hilarious and joyful kid on the planet and a blessing to everyone who he meets. What we were so scared about has not come true. So just wanted to put something positive about the scary diagnosis and help newly diagnosed moms rest easier that Holland 😉 Is not be such a terrible place.
Thank you for sharing your experience. Ours has been similar. All the worries that I had when Juliet was first born not only haven’t happened, but so many good things that I never even expected have. Good luck to your son in high school–we’ll be there in 3 years.
Hi Mark,
I just turned 38 and I’m currently 14 weeks pregnant. Like all the other women I had a positive NT of 3.7mm and higher HCG in my blood at 2.9. I had a ratio of 1:3 for T-21 only, I couldn’t believe it. I kept very positive about it all and then I took the harmony test and unfortunately the results came back by phone call as high risk for T-21 only. At the 12 week ultrasound the baby looked perfect other than the NT, nasal bone present, HR good, and was a great size (I know 12 weeks is just to small to know) I am booked in to have the ammio next week to get the true 100% answer which I already know will be positive. They wanted to do a CVS yesterday but after much reading I canceled and re-booked for the ammio on my 15th week so that the test was from the free baby cells and not the placenta. With the first screening positive and now the harmony positive I know there is no hope for a false positive in my case. Sucks being so healthy, perfect weight, took an extra 1000 mg a day pill of folic acid before pregnant and while, and this still happens. Seems so unfair. I guess my age was against me on this one. I did do the calculator you posted and put my readings in and I think it said something like the harmony would have a 10% false positive rate. I’m not sure if that is still true for me that both my screenings came in positive. We always hold onto that last bit of hope till you know 100%. I have 2 beautiful healthy girls (twins) from an IVF pregnancy. Funny this pregnancy was 100% natural so I thought that was so cool. This sucks but I have my girls and I will move on.
I will keep you posted!
I agree with you that the chance of your screen results being false positive are very low. With your screen results, you should have also received a copy or link to the Lettercase booklet Understanding a Down syndrome Diagnosis. While screens are not diagnoses, this booklet has been recommended by professional medical organizations to accompany cell free DNA results that are screen positive. You can view it for free on-line or your physician can request a hard copy at no cost. I understand the information you received from your screen results make it likely that your child has Down syndrome, I hope the information on Down syndrome will be helpful in understanding what a life can be like with that condition. BTW: I’m a twin myself–I hope your girls play more and fight less than my brother and I did.
I’m in Canada. Since I had my 12 week scan I have not even been to a doctor. I just went to get my harmony test. I literally mean I picked up the harmony package had a 10min class on how it works then left and went to the closest blood lab. The lab technician then asked me how long do these results take and that when I said 2 weeks, she then said good luck. Then I waited a week for those results. When the doctor called to give me the high risk results he booked me for the CVS which I changed. I have a 45min class to attend the morning of my amnio test regarding the amnio. Not sure if at the actual amnio appointment they will finally talk to me about anything. The doctor on the phone did ask if I will be terminating though. We don’t seem to have genetic doctors that you see in the states when you are screened positive.
My twins fight, fight, and fight. They are beyond a handful. But I sure look at them these days as miracles and I’m so lucky to have such amazing little girls that I will raise and watch them grow up.
Thank you for sharing how prenatal testing is being administered in your province; the classes at least seem an improvement on how women in the United States are typically counseled, i.e. no class whatsoever.
Lori im pregnant with twins too…were they born without downs? Sorry i didnt unddrstand from your post
Hi Mark,
At 41 y/o I was pregnant with my second child. I had the NPT (by Counsyl) at 10 wks which was negative. My OB reassured me that there was nothing to be worry about it and waited to order my first US until I was almost 20 wks. Then the appointment was finally on my 24wk. The US came back abnormal with high likelihood of T21. Had the ammonio which confirmed the diagnosis. Sadly we lost our precious one.
My OB contacted Counsyl and was informed that the %of fetal DNA was too low, less than acceptable for the test to be accurate (less than 50%). However, this information was never shared with my OB nor with me. Here is my question, are you aware of anyone trying to make these companies accountable for fully disclosure of the test quality and its limitations? I am concerned with the popularity of these tests and false claims as “screening” wonders.
Yes, Maria, I am aware of some lawsuits having been brought for a false negative cfDNA screen being presented as a true negative. I am not aware, though, of your specific facts where the lab failed to report relevant information, which would be an even stronger claim for liability. However, unfortunately, in the eyes of the law, depending on what jurisdiction you’re in, the loss of a child with Down syndrome would not be viewed as compensable damages. So, another route would be to start with a complaint to Counsyl directly to see how they respond. Other routes would be a report to your state’s Attorney General’s division of consumer protection. And, probably, the best route, if serious about pursuing, would be to speak with an attorney.
Hello Mark! I am going over my results from my Matera test! Your page has been comforting to me because it is saying my Panorama Risk score is >99/100
What does this even mean. My doc did tell me 99% our daughter will have Down Syndrome.
Is there a way you can help me interpret my test results better?
Amanda
Your doctor is giving you horribly wrong advice and hopefully he or she will take the time to review the fact sheets at the links in this post which explains why your results are almost never 99%. Your actual chances are based off of your age, which you can enter into the calculator at the post to provide you with your positive predictive value (PPV).
30 year old healthy daughter and 31 year old healthy husband have a healthy 2.5 year old. 5 weeks ago at 13 week first trimester genetic screen, NT scan showed a reading of 4.0 and a subsequent indirect cfDNA maternal test indicated Trisomy 21. Miscarriage had occurred in month prior to conception. Today’s 18.5 week ultrasound ( nasal bones present) was normal except for a heart ventricle ” bright ” spot. Don’t want risk of amniocentesis to ascertain diagnosis. Don’t want to get our hopes up but what is your calculation that this baby has Downs Syndrome?
Based solely on the mother’s age and the cfDNA test result, the calculator linked at this post reports a 61% chance that the child has Down syndrome and a 39% chance that the test result is a false positive. That could be adjusted if the NT scan adjusted the mother’s chance for having a child with Down syndrome. The ultrasound findings are soft markers which the cfDNA test takes precedence over.
Thanks so much! So how would a NT reading of 4.0 be factored into the calculation? We were told that ANY elevation of the NT was all calculated the same, whether it was a 4 or an 8. I did read a medical article that indicated the risk was proportional to the NT measurement ( the higher the measurement, the higher the risk of the baby will have DS). Is that correct?
I’m 25 years old, pregnant with my 2nd baby boy. Got all the testing down, for my age and what not I tested (1;1,500 for downs and 1;261 for trisomy 18/13) then went for the further testing to find out, they conflicted with everything I was testing high and when I got the genetic tests back they said I was high risk for downs went for the amniocentesis, and the ultrasound should everything was perfect and fine had the nasal bone and was to size and perfect. Got my pulmonary test from the amniocentesis and doctor said something about flags and having an extra chromosome, but said she has seen two times before the dna results come back fine. Wondering if you can further help me. Is there a chance my baby doesn’t have downs or is it a for sure now?!
It’s difficult for me to say based on what you share. The amniocentesis is considered diagnostic. If the amniocentesis full results (note, not just the FISH results) report Down syndrome, then that is considered diagnostic. If the amnio reports no Down syndrome, then that, too, is definitive.
Mr. Leach – I am reading these comments and your replies and I just have to say how kind and generous you are, to be taking time to reply to these fearful mothers and give them accurate interpretations of their results. With nothing in this for you, except to satisfaction of helping another at a very vulnerable time. I’m also saddened to see how much the doctors are misadvising their patients on what these results mean. My sister is in medical school to go in to OB, and I look forward to sharing this with her so that she can help her patients with accurate information on what these results mean. In the meantime thankfully I have her for when mine come back 🙂
Very thoughtful of you to take the time to submit your comment. For every woman receiving the results, it is a unique situation for them. I try to respond accordingly. I wish you and your sister well and hope she’s stocking up on her sleep now before residency and then actual practice begins!
Hello Mark
My wife is 41 in week 20 and we are considering doing a NIPT test. We contacted various providers and each one (Panorama, Maternity, Verifi, Harmony, Nifty) claim they are the best game in town. We are quite in the obscure on this. According to your experience which among the major 5 providers is more reliable and recommended.
Thank you for the very interesting information on your web site
Many thanks
Shmuel
One of the criticisms of the labs offering cell free DNA screening is that the only results reported for accuracy are from clinical trials, not from actual lab performance. So, there unfortunately is no way to determine which is the better screening test. That said, Harmony markets itself as being more accurate because it “targets” only the major trisomies, unlike the other labs which screen for many other conditions (for which they are not recognized by professional organizations). If your concern is about the major trisomies, perhaps that will inform your choice (Harmony is also the lowest-priced test).
I am currently year 12 student at Broughton Anglican Collage. I am undergoing my IRP (independent research task) and I was hoping you could help! My question is “Raising a child with special needs does not take a special family, it makes a family special” what are the implications on a family’s wellbeing raising a child with Down syndrome?
One of my objectives is to find out the emotional impact this has on the siblings of the child with Down syndrome (as well as parents). I was hoping I could get in contact with someone to do a short interview (either via email, phone or in person – I am based in Campbelltown) and ask them a few questions? these would be questions surrounding my objective, how it effects the family emotionally, what is the best way mentally to overcome any mental barriers, etc.
if I have missed any information that you want/need I am happy to give any information that you need. My CAFS (community and family studies) teacher is more then happy to write a letter stating what I am coming for if it is needed.
I hope you can help but I understand if you can’t! thankyou for your time
Dr. Brian Skotko and his colleagues published research on the issue you’re addressing. You can find all of those studies linked at this post. As far as speaking to a family with a child with Down syndrome, I would recommend getting in touch with your local or national Down syndrome organization and they will link you up with a family. I hope this helps.
Hi Mark, sorry for commenting here but I couldn’t figure out where/how to post a new question. I would really appreciate your opinion as we are going through a very difficult period with my husband. I’m 11 weeks pregnant, had a Panorama test done at 9w2d, and got a call thereafter that the baby is likely to have Klinefelter syndrome (XXY). The report says that the PPV (!) is 89% which is much higher than what the website would give (30%) me had they not disclosed the PPV. I am scheduled for an amnio in early June to confirm. I guess essentially my question is do you think that in this case there is truly only a 11% chance for not having XXY? Also just FYI I’m on Clexane (heparin) injections, could it have somehow impacted the results? Any insight you could share with us would be much appreciated!
I am not familiar with Clexane affecting the accuracy of screening tests, but that doesn’t mean it didn’t; something for you to ask your provider about. Regarding the PPV, Panorama and other cfDNA screens are not recognized for their claimed accuracy for sex-based conditions like XXY due to insufficient number of studies being done to show their reliability. I would put more weight on what the online calculator says until Natera provides a fuller explanation for why it quotes the PPV at 89%–something your provider could request for you.
Mark, I really want to thank you for your site. I have been reading as much as I can….
I was not sure where to ask this question: I am 42 and My QUAD screen ( triple screen?) came back as a greater than 1 in 3 risk of downs. I have been battling my thyroid during this pregnancy, and know for fact that it was off during both blood tests. In fact, I am fairly certain that I had HCG induced hyperthyroidism at the 12 week test. Knowing how the thyroid affects hormones, I cannot help but wonder if this affected my higher HCG numbers. Now I have moved on to the Panorama test, and am wondering if you think there is a huge different in both tests? Amnio is not an option for me, and I’ll be keeping the baby either way. I’m just curious as to how these tests truly compare to eachother.
Thanks so much,
Lisa
Thank you for the compliment and I hope the site has been helpful. I’m surprised that they would report a conventional screen result as high as they did. Even at 42, tests like QUAD have high false positives, often for the reasons you cite, i.e. there can be unrelated factors affecting what the QUAD measures to correlate to Down syndrome. Conversely, screening tests like Panorama do test DNA from the pregnancy. As covered at this post, it’s not definitively DNA from the developing fetus itself, which is why there remain false positives and false negatives. However, because it is DNA from the pregnancy, it is far more accurate than tests like QUAD for the few conditions that cfDNA screening has been recognized for, e.g. Down syndrome, T18, T13, and sex.
Hi Mark,
Your site has helped me understand the NIPT screening greatly and I thank you. I am 29 and 16 weeks. My Progenity test provided us with a PPV of 50%. We have seen no markers on any ultrasounds. Does the absent sign of no markers decrease our odds of our baby having DS? Thank you for any insight, again, thank you for your site.
According to the most current practice guidelines, ultrasound markers can be taken into account as indicating a higher chance for Down syndrome, but they do not say the absence of such markers affects the PPV of cfDNA screening like Progenity.
Hi! My daughter tested high risk in her first trimester. She will b 20 weeks on Monday. 24 yrs old when the baby is born and had the NIPT done and she got a call telling her the test came back 99% positive for trisomy 21 and that she could abort up to 24 weeks. Obviously they r devastated. They did the extensive ultrasound with the specialist and he told them that everything looks good except some calcium and the heart and possibly a very tiny whole in the her little heart but that it was so small that he wasn’t even comfortable telling them it could be something wrong. He then sent them for the NIPT test. With that coming back positive they r now going to take a closer look at the baby heart. Out of all that I have read yours is by far the most informative. I just wanted your thoughts on the possibility of the baby truly having DS?
Based on your daughter’s age, the online PPV calculator reports the likelihood of her result being a true positive as 51% with a 49% chance that it is a false positive–so essentially a coin toss. While it would be rare for your daughter to have a child with Down syndrome at her age, it does happen, just rarely. So, the NIPT result suggests an increased chance, but also almost as likely a chance that her child does not have Down syndrome as the chance is that she does. Professional guidelines recommend parents receiving accurate, up-to-date information about the tested-for condition. Here is the link for the recommended resource on Down syndrome. In my personal experience, the best resource I found was my local support organization. I hope your daughter receives good care from her providers going forward.
Thank you so much for responding. From what i understand there are no other markers on her ultrasound other than the calcium found. It was the genetic counselor that told them that there was a 99%chance that the baby had DS and based on what i have read on your site this could be malpractice? The crying and stress of it all seems so unfair to them. do you know what the miscarriage rate is for amnio at 20-22 weeks? I believe the stress of not knowing is worse than actually getting a confirmation of DS
Historically, the risk of loss with an amnio has been stated as 1%, but there were some studies over a decade ago that found at two hospitals where there were experienced practitioners and staff, the risk of loss was lower than that. Ultimately, the only risk of loss that is relevant is what the doctor and the facility where it is being performed have experienced, so I would suggest asking for that. As far as the incorrect counseling your daughter received, yes, that is contrary to even the National Society of Genetic Counselors guidelines. The NSGC has put out a helpful fact sheet on understanding cell free DNA screen results, which can be found here. I would suggest providing that to the genetic counselor who counseled your daughter so he or she doesn’t make the same mistake in the future.
hi! So my daughter had her appt yesterday and they pretty much scared them even more. Told them that since the NIPS came back positive that they are almost positive the baby has DS. That the pin size hole in her heart is still there and that there was fluid in the brain but that came back at 9.5 and all that i have read states that up to 10 is normal and the calcium around the baby’s heart has gone down and the nasal bone is smaller than it should be. I just feel that maybe the specialist seen the positive NIPS test and now started seeing everything through DS eyes, does that make sense? I’m trying to convince her to do the amnio to know for sure because it feels that we are still in the unknown
It does sound like they’re viewing everything based on the cell free DNA screen result. I wonder if they even know of the 49% chance that it is a false positive?
Good Morning! I forced my daughter’s dr to give me her lab work. The company was MaterniT21 and in big bold letters it does say positive for T21. but in verry small letter further down it does show her PPV at 46.4%. the did find a marker of calcium on the baby’s heart, which has gone down since her last ultrasound. the pin hole in the heart is still there but has not grown. And apparently in this last ultrasound, which was only done 2 weeks after the 1st one, now they are saying there is an under developed nasal bone. 2 weeks prior same dr had told them that other than the heart issues, everything else was where it needed to be. From what i understand these other soft markers than compromises the 46.4% correct? Her ob/gyn has referred them to a different specialist since they have revived so many contradictions from the 1st specialist
The MaterniT21 result takes precedence over soft markers according to current guidelines. Glad you got the actual lab report and that the PPV was listed on it.
Really? Thank you so much! It is greatly appreciated that you take time out of your day and respond to everyone. There is nothing like some peace of mind.
Based on ur experience what are your thoughts on the following… Positive maternit21 with a 46.4% ppv. Soft markers are hole in heart. No nasal bone. And liquid in brain measures 11 when normal is 10. Now I know that these markers are not only for DS. But is it realistic to think that DS is the most logical? Watching ur kids go through the emotional rollercoaster is unbearable. She doesn’t want to risk the amnio and she seems to think that everything is fine. I don’t know if she’s in denial or if her mommy instincts are correct.
A 46.4% PPV means the odds are greater that the test result is a false positive than a true positive. If your daughter is planning on continuing the pregnancy no matter what, then her aversion to the risk of loss associated with invasive testing is understandable. If the uncertainty weighs greater than the risk of loss, then she may consider confirmation through invasive testing. And, per professional guidelines, if she is considering termination or would consider termination if the screen result is a true positive, then invasive testing is recommended.
Hi Mark,
I never write on these posts, but in this case I’m too distraught not to and your advice to others seems sound. I am 30 years old at 16 weeks, and got a call yesterday from my Dr. that my pregnancy is high risk for Down Syndrome by 28%. My Dr. said the tests are 99% accurate and if there’s an abnormal test, it means an abnormal pregnancy. I am going to go through with the amniocentesis, but am confused by the 28%. She didn’t explain how they got that percentage. Is it a 1/4 chance? The calculator you shared with others says the test would be 68% accurate for me with a 32% false positive possibility but I’m not sure if that stands with my given percentage. I have no idea if you’re still answering these posts, just thought I would try. Thanks I’m advance.
I was traveling this week, which explains my delay in responding. I would ask your doctor to see a copy of your lab report and see how the 28% is listed. If it’s listed as the positive predictive value or PPV, then that means the test has a 28% chance of being a true positive and a 72% chance of being a false positive. Like many practitioners, it sounds like your doctor is confused by the lab’s marketing of “99% accurate.” Feel free to share this fact sheet from the National Society for Genetic Counselors which was written for physicians about how to understand cell free DNA lab reports. Professional guidelines also recommend that patients receive information about the tested-for condition. Here is the link for the recognized resource for Down syndrome.
Had the maternit21 positive for xxy I am 42 years old how accurate is this type of screening for SCA.
Professional guidelines do not recognize tests like MaterniT21 for conditions like XXY. However, this online calculator reports that based on the condition and your age the chance that your test is a true positive is 64% and the chance it is a false positive is 36%. You can ask your doctor to follow up with Sequenom, the maker of MaterniT21, to ask what their PPV calculation is for your test, as that is supposed to be reported with your test result.
Hi Mark
Have pretty much read every single comment on your site. Came across your page trying to find the true and correct information on the Harmony test.
I’m 32 and 13 weeks pregnant. Went to have the 1st trimester scan and was told the neck thickness was in the high range but they could not get baby to turn around to measure the nasal bone so I don’t know what that is.
Then they told me to get the NIPT test done instead, which I did. They called me a few days ago and told me it came back 98% positive and I specifically then asked, ‘does that mean there is a 98% chance my baby has Down syndrome?’, the Dr said yes.
I was in total shock and devastation and pretty much thought it’s a definite. I went to the specialist yesterday and he then clarified that it was just a screening test and told me after reading the 2018 medical journal guidelines, once I’m in the ‘high-risk’ group after the NIPTS, the percentage that my baby has downs is a 45% chance. He did a scan afterwards and said everything looked good in terms of heart and grow size, (nothing about neck thickness) but I have to wait 3 weeks to have an amnio and it is agonising not knowing and how to cope or what to think until we know for sure. Does that figure seem right to you? I did your online calculator and it came out with a 68% chance of it having down Syndrome. We weren’t given a probably reading (like 1/400) It’s so confusing and we are so upset the way we were told false information from our NIPTS result. My fiancée is 36, we’re both healthy and no family history, just seems so unfair.
I do appreciate all the support you give stressed out parents on here. Thank you for helping us understand the true meaning of these tests. Any advice is greatly appreciated
It is reckless that your initial practitioner is still quoting the erroneous 98% figure. I’m glad at least that your specialist read up and provided you more accurate information. With the online calculator reporting a 68% chance of true positive and a 32% chance of a false positive, that probability would take precedence over any soft markers observed in subsequent ultrasounds. You may ask your specialist to contact the testing laboratory to see if they have a more refined, specific probability figures. Also, you may find the professionally reviewed and recommended information about Down syndrome helpful. It can be accessed at this link.
Mark I read your article on the potential to cure Down’s Syndrome with a shot. It was written two years ago, so has the research progressed any further. I am the father of a child diagnosed with Trisomy 18. I know that your article was about Trisomy 21, but I assume that the same idea would work for Trisomy 18. Do you know of any progress in experimental treatments? I know it’s a long shot, but I am desperate, and I am looking for anything that may help.
I am not aware of any developments regarding treatment that would “turn off” the third copy of the chromosome.
hello mark
my PANORAMA report, RISK BEFORE TEST 1/171, RISK AFTER 9/10, T21 HIGH RISK,
What does it mean?
Thank you
I would put your age in and the condition tested for into this online calculator to see what your chances are. I would also ask your provider to ask for clarification from Natera, the maker of Panorama.
Hey Mark,
I’m working with Down Syndrome of Louisville and have been researching our growth over the past couple of years. During this time, we as a collective group wanted to get a greater gauge on the development and possible growth of the Down Syndrome population. Seeing as though you are an expert in the field, we wanted to hear your insights so that we are able to make more data driven long term decisions. We hope to hear your thoughts!
All the best,
According to the most current estimates, the number of babies being born with Down syndrome has essentially held steady for years. However, with the average age of motherhood increasing, there should have been 30% more babies with DS being born, but for prenatal testing and selective terminations. Based on this dynamic, I would not expect the Down syndrome population to grow. At best it will hold steady, but the greater probability is that there will be fewer babies being born with Down syndrome as prenatal testing continues to expand and be covered by insurance.
Hi Mark,
I just had a son and he is Trisommy 21 syndrome. This is shocking and it is very hard for us to accept it. While looking at google I found this link where it says that this extra chromosome can be remove, is it true? if possible please let me know i would like to contact you and cure my son permanently. Please reply.
The method of “turning off” the extra 21st chromosome is still experimental and only successfully performed with individual cells in a laboratory, not in a living human being.
Mark,
I am 29 years old, had the quad screen done (this is my third pregnancy-other two perfectly healthy, no issues) the results of my quad screen show that this baby has a chance of having DS. 1/55 is the rate that I was given. I did not have a first trimester blood draw done, I’ve just had the quad screen. Is this something to worry about? Our provider is sending us on to a maternal-fetal doctor to do further testing. What are the odds that this test is correct? My husband and I are kind of freaking out and really wishing that we would have opted to not have the quad screen done to avoid the stress and worry. Neither of us have any family history of DS or any other genetic disorder.
Based on the rate you were told, your quad result has a 1.8% chance of being a true positive and a 98.2% chance of being a false positive. Hence why quad screens are not considered that reliable. If you’d like to learn more about Down syndrome, this resource is recommended to accompany any prenatal test result by all major medical organizations.
Hi Mark,
I am 17 weeks pregnant today with my third child. I am 29 years old, will be 30 when I deliver.
I had the quad screen done and it came back positive. The chance for DS is 1/55, which is typically 1/740 for my age. I’ve read all over on your site and many other places and I keep seeing the trend that the quad is inaccurate and often gives false positives.
We have been referred to a MFM for further testing, but my husband and I are wracking our brains and stressing, and part of me feels like we do not need to be. What are your thoughts? We really did not get any feedback from our doctor on any of this. We were just told the quad came back positive.
To be told that your quad test came back “positive” is a bit misleading, as that suggests greater accuracy than what the quad test can actually provide. Your chances that the quad test is a true positive is only 1.8%, with a 98.2% chance that it is a false positive. Hopefully that helps.
Hi Mark,
I am 31 and received a high risk for T21 on my Panorama screen. It showed 9/10. However, I am quite certain the gestational age was incorrect. I have been given 2 different due dates which are a week apart. They went with the later date making me 10 weeks 1 day when the screening was done. But I think I was 11 weeks. Do you know if incorrect gestational age could cause a false positive?
I have not heard of gestational age being a factor for a false positive. However, you can check your chances at this link by entering your age and selecting T21.
I am leaving a comment here as there is no ability to comment on your article regarding the chances of having a baby with Down Syndrome. I have a somewhat similar background to yours; I’m an attorney and have a Masters in epidemiology. I terminated a pregnancy for T21, based on a positive Panorama screening and a positive CVS. I also had several markers on an ultrasound including a larger than average nuchal measure as well as septations. I was confident the testing was not wrong. I fully understood when I received my positive Panorama test what the PPV was based on my age (94%). I was about 11 weeks at the time I received the result. I also understood that there was a reasonably high chance the pregnancy would miscarry (the information I found at the time was that there was about a 32% chance the pregnancy would miscarry before term).
I have to say that I disagree with the premise of your article; in fact, it makes no sense to me at all. You say that “even a diagnostic test will not tell you your odds for having a child with Down syndrome” because of the miscarriage risk. This is technically true, but there is still more than a 50% chance that you will have a child with Down Syndrome if you have made it to a NIPT result and have a positive diagnostic test. And the chances you are carrying a healthy child are zero. Either a woman is willing to carry a child with Down Syndrome to term or she isn’t. If she isn’t, then the fact that she has a 30% or 40% (or even 99%) chance of miscarriage isn’t going to matter. There is simply no point in continuing the pregnancy. While she may not actually give birth to a child with Down Syndrome, she is not going to have a healthy child; she either delivers a live baby with Down Syndrome or she miscarries. If she is willing to carry the pregnancy to term, then she almost certainly would have been willing to do so whether she knew about the miscarriage risk or not, as she is clearly willing to have a baby with Down Syndrome.
As this is very obvious, and you appear to be an educated person, I cannot understand why you take the position you do. I would really appreciate an explanation (in response to this comment, not privately by email). Thanks.
I conclude by saying the miscarriage rate is relevant information that should be shared after a test result. From your comment, you sought out the miscarriage rate when you received your test result, which supports that it is relevant information that should be shared.
But the information had no effect on my decision. Ultimately I decided that I did want not to have a child with Down Syndrome. I assume you will respond that you are just interested in women having all of the relevant information to make a decision, but your position generally on the issue is obvious. Also, the way it is set out in your article, you are impugning the utility of the tests because they don’t tell you your odds of actually giving birth to child with Down Syndrome. But they tell you that the fetus you are carrying does in fact have Down Syndrome. In my opinion, it is really just likely to confuse people who don’t have the same level of knowledge as you or I do, and make their decision more difficult. I am very interested to hear how you consider that the information could actually have a practical effect on someone’s decision to terminate or not.
Your personal experience is according to your values and what you consider important; others may think differently. There may be some moms who would prefer to avoid having an abortion and may instead wait to see how “nature takes its course” rather than proactively intervening. Tests like cfDNA screening or quad, or any other screening test do not “in fact” tell you the fetus you are carrying has Down syndrome; only diagnostic tests (and even those retain a chance of a false report, albeit statistically low enough so that they are considered diagnostic).
Hello Mark. I am a 36 year old women who is 14 weeks pregnant. I recently was told My baby was high risk for ds. I decided to have a cvs done and the preliminary reading came back as that found an extra chromosome but that’s all the infor they gave me. I have to wait to the final results to determine if the test was positive. My question is will the final results be the same as the preliminary results.
My apologies for the delayed response as you likely have the final test results by now. But, to answer your question, while rare, there are times when preliminary reports from a CVS are contradicted by the final results. This is because a CVS tests cells from the developing placenta, which is the same source of cells that will become the fetus, however, the fetus and the placenta can have different cells.
Hello Mark,
I am 40 and 20 weeks 5 days pregnant with my 4th child. I was diagnosed with Trisomy 21 through Harmony testing and my initial first trimester NT test combined with the bloodwork. My first NT measurement was high at 2.9mm which was still okay because 3 was considered high everything else in the ultrasound was fine nasal bone was seen and all other measurements were right where they should be. At my second anatomy scan at 20 weeks Nuchal fold measured 6.2mm which the doctor said would still be fine if harmony came back negative there were no other markers seen. Harmony came back positive at 80 to 90%. Scheduled my amniocentesis to confirm and talked to the genetics counsellor there and she said given the combined test results I could expect a confirmation of trisomy 21 she was 99% sure of it. Tried the online calculator and it came back 7% that it could be a false positive. What do you think of this.
I got the same results with the online calculator. The Harmony results would take precedence over any other screens for Down syndrome. Professional guidelines further recommend that you receive written information about Down syndrome. The recommended resources can be found at the Prenatal Resources tab on this website, linked here. I hope they are helpful for you.
HI Mark, I have a question regarding my NT scan and subsequent NIPT results. I am 42 (41 at time of conception) and my husband is 36. This is our first pregnancy and we are over the moon. We got pregnant fast and naturally. All was going well (I had at least 4 ultrasounds in first trimester already) until my NT scan a few weeks ago at 12 weeks.
The NT measured 4.8. The doctors cast a pall over everything and gave me lots of anxiety. I immediately did the Materniti Genome bloodwork test- I think it’t the most comprehensive test they offer. Results finally came back yesterday after a grueling ten days of waiting. They DID find an abnormality- for something very, very rare called Wolf-Hirschhorn (microdeletion of 4th chromosome).
However, the PPV of the test is 4%. The tech at Sequenome told me the sensitivity of the test is 96.2; the specificity is 99.7. The fetal fraction by the way was 5%. My genetic counselor (at a very reputable hospital here in Charlottesville, VA) said the sensitivity is 91%; the specificity is 99.7%. This to me seems like it’s very likely my baby DOES NOT have this abnormality.
I had another US after seeing the bloodwork. The NT has decreased slightly to either 4.7 or 4.1 (two different readings). There is no other fluid accumulation or anything. Everything else is status quo– heartbeat 161, measuring 65.
I am scheduled for a CVS next week. I will be 13.5 weeks along. I am a tad concerned about endangering the baby and wondering if it’s selfish not to wait for an amnio.
I read somewhere that a CVS tests fetal DNA and not the baby’s. Does that mean it’s not as accurate? I also had a chemical pregnancy 3 weeks before getting pregnant with this baby; could that baby’s DNA be in my blood?
What do you think?
Thank you SO much for taking the time to answer everybody’s questions. We are grateful to you.
C. H.
Tests like Sequenom are only recognized by professional guidelines for being accurate for Down syndrome, T18 & T13, and sex. That’s it. Everything else they test for does not have enough reported studies to support the labs’ claimed accuracy. That said, if Sequenom is saying its PPV is only 4% then that means you have a 96% chance that your test result is a false positive. CVS tests cells from the placenta which shares the same DNA as the fetus, but can also have its own idiosyncratic DNA. My understanding is that the free floating cell-free DNA that Sequenom tests leaves the mother’s bloodstream upon the ending of the pregnancy, so your prior pregnancy’s cfDNA should have left your system by the time of this test.
Hi I am 27 years old will be 28 by the time baby is born. This is my second kid, a boy this time. We were so happy to find out we were having a boy until the dr came in and said it seems as though there are a few soft markers for t21. We were sent to see high risk dr and to do a fetal echo. Everything with the echo was great. They did another ultrasound with the high risk and said some markers went away but there were 2 with measurements just slightly off. We just got the panorama results back and it shows high risk for t21–9/10 with a fetal fraction of 29.4%. I have been so sick over these results. I’m just so shocked. Is there any possibility it could be a false positive?
Per this online calculator, based on your age, you have a 54% chance that your test is a true positive and a 46% chance that it is a false positive. So, almost a coin flip that you’re either positive or negative.
Hi Mark, i been researching the last couple of days and stumble across your useful page. I been quite stress and sad as i did my 12 weeks maternal screening and have 1 in 10 chance baby have down syndrome. I am shock at this news as my husband and i don’t have any family history of down syndrome. Iam 32 years old, first pregnancy. NT scan was 1.17, my beta hcg 5.21 which is high and papp A is 0.58 which gave me that odd of 1:10. But for T18 odd is 1:10000. I have hospital appointment next week and they will book me in for Amnio. Just before the blood screening i had food poisoning the night before which empty my bowl completely. Do food poisoning and severe vomiting have any affect on blood test? i can not find anything about it online. What are your thoughts? Thankyou
I have not heard of food poisoning affecting results, but that doesn’t mean it couldn’t. Did you have a cfDNA screen AKA NIPT? If this is just based off of a nuchal combined test, i.e. ultrasound and blood test, it’d be surprising if your likelihood was 10%.
Dear Mark,
I am age 39 and have just been told that I have a 1/45 chance that my little one has Down Syndrome. I am waiting on the Harmony test results. I understand that this is 2.2% chance that the baby has Downs and am trying to work out where I am at. The NT was measured at 1.4 so within normal limits and the midwife says that the high risk result is mostly down to my age.
Your thoughts would be great, thank you!
According to the most current guidelines, your Harmony result should take precedence over all conventional screens for Down syndrome (and Trisomy 13 and 18, but not for other conditions, necessarily). According to this online calculator, a “positive” result for Down syndrome would have a 91% chance of being a true positive and a 9% chance of being a false positive. If you receive a “negative” result, the chance that it is a true negative is greater than 99% and the chance that it is a false negative is less than 1%.
Hi Mark. Unlike most of these comments, I did get a low risk score on my Panorama test back in August at 10 weeks pregnant. I don’t know numbers others than 1 in 10,000 which they promote on their site. I am 35. I understand the odds of that being wrong are low however I don’t really believe in low odds anymore since my husband alone has had 3 one in a million health problems happen to him so I go by facts. My 20 week ultrasound last week showed two soft markers—ecogenic bowel and a thick nuchlar focus. It was pretty think at 8-9mm too. I really don’t want to get the amniocentesis if I am still considered low risk based on the combination of my low risk test results and my 2 soft markers. If my age and those markers are big enough red flags and I am now considered a moderate risk than yes I will get the invasive test.
According to this online calculator, based on your age and your screen negative result, the chances that it is a true negative are greater than 99%. According to the most current guidelines, a cfDNA screen result takes precedence over soft markers for the conditions the cfDNA screen tested for. That said, discussing your concerns and questions with your provider and/or a genetic counselor is also recommended by the guidelines.
Dear Mark,
thank you very much for your blog, I couldn’t find this information anywhere else on the Internet.
I am hoping for your reply as I have the most difficult time of my life – just received CVS result positive for Down’s Syndrome.
I spoke to the consultant in the hospital (I am in London, UK) and they all are confident that it is 100% accurate result. They told me that otherwise laboratory would pick that it is Placental Mosaicism and state it in the report. Also when I asked if they ever had false-positive result they told me not, but they are not investigation or doing tests post mortem on foetuses as it will be considered here as a waist of NHS money. So how they can be confident then that CVS is always accurate?
After reading your site I am not sure..
I booked Amniocentesis for tomorrow at another clinic.
Have you ever heard or read about Amnio having different result to CVS for Down’s syndrome and CVS being false-positive?
I read somewhere that it can be case for 13 or 18 chromosomes but usually CVS is very precise for Dawn Syndrome.
What do you think? Would you do Amniocentesis in my case?
I look forward to your reply.
Kind regards,
Alexandra
I am not aware of a an amnio having a different result than a CVS, primarily because having two diagnostic tests is rare. I would expect the false positive rate being higher for T13 or T18 is due to each of those relative rarity. CVS has a reported higher false positive rate than amnio, but both CVS and amnio are considered diagnostic tests because each of their false positive rates are extremely small. Whether I would have an amnio is less relevant than discussing with your health care providers, hopefully a genetic counselor, about what your goals and concerns are. I hope you receive the information you need for feeling certain.
Thank you very much for your reply Mark!
I just have realised yesterday that there maybe the following connection – I have been taking Clomid for two months and than stopped it approximately one month and a half before conceiving. I saw some articles on the Internet that Clomid can cause Dawn Syndrome. Maybe it was still in my system.
Did you come across such kind of cases or evidence of this possibility? If I knew about this risk I would never take this drug..
I am medical professional myself but completely lost my mind in this situation so apologies for all these questions..
I was unaware of this possible side effect from Clomid. From a brief google search, I see some posts mentioning it is related, but I did not dig deeper to see how it may “cause” Down syndrome.
Thank you Mark.
I think Clomid can “cause” it by increasing quantity of eggs during ovulation, and maybe not all these eggs would get to this stage otherwise as they have some fault in them, or Clomid made them to mature too fast and this causing chromosome non-disjunction or something else.. But nobody knows for sure of course..
That could be the explanation, though, my understanding is that all eggs are formed and present even in utero (however, I’m not an embryologist). Rather, my inference is simply that by promoting the expulsion of eggs from the ovary it increases the chance of the egg having two Chromosomes 21 being released. But, again, I would defer to a medical expert on the true explanation. Regardless, I’m glad you found this site of some help and I wish you the best.
Hi mark! Im 37 yo and 15 weeks pregnant. I had the materniT21 test and it said positive for down syndrome but it said my PPV was 88.9%. Am i understanding it correctly that with a PPV of 88.9%, i have a 1:146 chance of having a baby with DS? Meaning i have a 0.6% chance of having a baby with DS?
I would confer with your healthcare provider to confirm the test result and the reported PPV and what it means. What a PPV of 88.9% means is you have close to a 9:10 chance that your test is a true positive, i.e. that your pregnancy is actually positive for Down syndrome, and a 1:10 chance that it is a false positive, i.e. that your pregnancy is not positive for Down syndrome. You can find out more about Down syndrome at the resources listed in this link.
Hi there,
Thank you for your article I find it the most informative thing I’ve read.
At our twelve week scan baby position meant we could not get the nt measured however the sonographer said if she was worried she would have us back but to her eye all look good. So I was offered the quad test at 15 W. I’m 37 other wise healthy, bloods all within range and I got a 1 in 9 chance of downs. I was then offered nipt (new to Nhs in Scotland illumina veriseq solution v2) it came back high chance of t21.
Had my anomaly scan at 19 W every measurement as it should be showing heathy growth and nt was well within range.
So they have me in for a amnio on Tuesday.
I have used the calculator.
However the mw has said the nipt is pretty definite. What would your opinion be?
Thanks again
As you’ve seen from the calculator, based on your age and a result for Down syndrome, the chance your result is a true positive is 86% and the chance it is a false positive is 14%. The amnio is considered diagnostic. If your midwife is saying NIPT is pretty definite for women your age, the PPV would support her. However, if she’s saying this to women 30 and under, PPV is close to a coin flip and she should improve her counseling. Plus, even if “nipt is pretty definite” for women 37 and older, it remains a screening test–there remains a chance for a false positive and all guidelines instruct to have diagnostic testing before making any irreversible decisions. If you would like more information about Down syndrome, see those listed here. Also, the UK-based, Down Syndrome Education International is a fantastic organization.
Hi again
Thanks for your reply. So I had a amnio to confirm the t21 diagnosis.
Oddly the amnio came back today (very quick) and said the baby has no chromosomal issues. So no t21 ,18 or 13!
So 3 weeks ago I got that 1 in 9 chance of t21 through quad test then a week later got the positive high chance of t21 through nipt. To get the amnio results back as all clear is just surreal?
Is there a way to find out why I had these positive chances?
Some false positives are attributed to lab and human errors: testing the wrong sample, a contaminated testing process. Absent that, false positives generally are due to a phenomenon called “confined placental mosaicism.” I write more about this here.
So after some digging and bloods been sent to the company I apparently have confined placental mosaicism and that was the reason for the high chance nipt.
Is there any reason for concern now would you say?
With regards to the health of your baby, the amnio is the diagnostic test and controls over the NIPT result. According to professional guidelines, you should have confidence that your baby is unaffected. With regards to confined placental mosaicism, I am not aware of that being a cause for concern, as it is a naturally occurring phenomena. But, you should discuss with your health care provider as I am not an OB/Gyn. I wish you a healthy delivery and good bonding with your child.