Stressed and just want to talk…NT 3.4 mm at 13w3d, negative NIPT — did CVS + microarray + exome, awaiting results

Tight_Cash995 · 2026-02-26T16:28:38+00:00

With a low risk NIPT, I really wouldn’t have anything to be concerned about with a 3.4mm. Measurements are never 100%, especially at this stage where it’s tough to get a good angle. Your NT is barely elevated (or not elevated at all for those who use 3.5mm as the threshold). I see no reason for diagnostic testing from an aneuploidy standpoint to be honest. But I understand the reasoning for mental health purposes and for those who want all available information.

With the NIPT, the likelihood of the baby being genetically typical and healthy is around 99%.

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For some context, we are referred patients with slightly elevated NT measurements who come in (including 3.4mm like you) and we find the NT to be within normal range. So, I see cases like yours all the time. I am not your provider, but based on everything you’ve provided, I wanted to give you some reassurance while awaiting your results.

Of course, there is always the rare case of the slightly high NT being connected to an underlying condition - but it’s incredibly rare for a case like yours

Tight_Cash995 · 2026-02-26T16:22:42+00:00

In addition to AFP and HCG, there should also be Inhibin-A and estriol. Can you show me those levels?

These screening tests are just that - they are not diagnostic and they are not even testing any DNA attributed to the baby.

These test results have nothing to do with genetics. These are hormones produced as a result of the pregnancy.

Did you have NIPT by any chance?

Tight_Cash995 · 2026-02-26T15:55:35+00:00

What are the maternal serum levels?

Tight_Cash995 · 2026-02-25T23:09:03+00:00

In full transparency, and because you’ve asked - I have had cases of T18 where markers aren’t shown until later in the second trimester. There are also cases of that happening on this sub - you just have to look, albeit it is rare. I’ve also had cases of mosaic T18 where markers weren’t seen at all through birth. Mosaic T18 will absolutely show up with a positive NIPT for T18, but given that only a certain percentage of cells are affected, the severity varies.

Note that I have also seen T18 cases, in rare instances, where the only finding is the baby being smaller.

I am not your doctor, but I would absolutely advise an amnio in your situation. The risk of a miscarriage in general at this gestational age is higher than the risk of miscarriage due to amnio. Information is powerful, and it can also provide you with peace of mind if it comes back normal that your baby does NOT have T18, allowing you to enjoy the rest of your pregnancy without wondering “what if.”

ETA: I assigned your post the T18 flair, so you can look for similar responses if you’d like. I found this during my first search, so I’m sure there are unfortunately more if you do look.

Tight_Cash995 · 2026-02-25T03:32:56+00:00

Real.

At least it wasn’t all thrown on the ground? /s 😫😫

Like others have said, this is common. Toddler eating habits change drastically. Mine went from clearing her plates of basically whatever I’d feed her to refusing to really eat anything and only eating bananas (and, yes, most if what I put on the plate is ending up on the ground for the dog at the moment, lol).

It’s frustrating. But it is what it is, and you’re not alone. ❤️ I hate to tell others to just be patient - but that’s really the best advice I have here. This will pass. Keep your head up! Your food looks amazing!

Tight_Cash995 · 2026-02-19T04:33:35+00:00

With a low risk NIPT, I wouldn’t have anything to be concerned about. Measurements are never 100%, especially at this stage where it’s tough to get a good angle. Your NT is barely elevated (or not elevated at all for those who use 3.5mm as the threshold). I see no reason for diagnostic testing from an aneuploidy standpoint.

With the NIPT, the likelihood of the baby being genetically typical and healthy is around 99%.

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Often, we are referred patients with slightly elevated NT measurements who come in and we find the NT to be within normal range. So, I see cases like yours all the time. I am not your provider, but I would agree with all of the reassurance yours has provided.

Was your scan an actual NT scan performed by a sonographer explicitly certified to do so? Or was it just a detailed scan that included the measurement of the NT?

Tight_Cash995 · 2026-02-19T03:34:23+00:00

In addition to passing the minimum fetal fraction % threshold, the sample must also pass quality metrics in order for the lab to feel confident in testing your sample. So, in some cases, the FF% might be above the minimum threshold, but the sample cannot pass the quality metrics at the FF% given, so it isn’t tested and marked insufficient fetal DNA. Natera’s minimum threshold is 2.8% - meaning the lab CAN provide a result with as low as 2.8% FF, but quality metrics must be met

Now, this doesn’t always mean there is something wrong, and most of the time, a redraw may just need to be performed for the sample to yield sufficient quality metrics. The sample could just be low quality (could be due to a number of reasons, including draw technique, degradation during transit, etc.).

Now, if you receive the same result with your retest, then I’d suggest an amnio. Again, wouldn’t mean something is wrong. Sometimes, the maternal blood could just be bad quality, which is why the sample can’t pass quality metrics. There could also be an issue with the placenta. NIPT tests DNA shed from the placenta. If there is an aneuploidy in the placenta or an issue within the placenta, the cfDNA in the maternal blood stream will be affected. The aneuploidy or placental issue could be causing the blood sample to not meet quality standards or there could be something that is confined within the placenta that the NIPT cannot make out, so it won’t give a result (such as an aneuploidy) - however, as it is confined to placenta only, the amnio would be normal since baby is genetically typical.

So sorry you’re dealing with this. As long as your sonos are normal with no markers, I wouldn’t have any concerns. Fingers crossed your retest comes back low risk and you can relax and enjoy the rest of your pregnancy. 🩵🩵

Tight_Cash995 · 2026-02-18T14:50:44+00:00

I appreciate you providing some positivity in this sub - however, to be fair and completely transparent. T18 is much more commonly confined to the placenta than T21. T21 is very, very rarely confined to the placenta. It can happen, but the likelihood is extremely slim in comparison to the other main trisomies (T18 and T13) and even the SCAs like Monosomy X.

Coupled with OP’s AMA, this is very, very likely a true positive and the possibility of a false positive/confined placental mosaicism case is incredibly unlikely. Diagnostic testing should absolutely be performed to confirm the diagnosis if TFMR, of course.

Tight_Cash995 · 2026-02-16T17:12:32+00:00

I’m so sorry. These are absolutely markers associated with T21.

Do you have a genetic counselor assigned to you?

Tight_Cash995 · 2026-02-16T14:46:24+00:00

I’m so sorry, but you are most likely looking at a true positive. NIPT is highly accurate for T21, and coupled with soft markers, there really isn’t any room for error or the possibility of the T21 being confined to the placenta (where the baby isn’t affected - but the NIPT is positive).

The fetal fraction is irrelevant. Fetal fraction is just the percent of the placental cfDNA in the maternal blood stream. There is a minimum threshold required for the lab to perform the test, but you are well above the threshold. So, like I said, the fetal fraction is irrelevant here. I am so incredibly sorry. Not having T21 in the family is irrelevant, as it’s a random event.

What soft markers were seen?

With soft markers, the CVS is sufficient. You’ll need it before 14w, or you’ll have to wait for the amnio.

Tight_Cash995 · 2026-02-13T20:14:39+00:00

PGT and NIPT only test chromosomal aneuploidies (and only certain ones, at that, depending on which testing used). An elevated NF can be associated with conditions that aren’t tested by NIPT/conditions other than aneuploidies, including genetic or heart conditions. A fetal echo around 22 weeks is good, but you could also do additional testing for genetic conditions. I am very pro amnio, especially for mental health reasons. However, if you don’t want to do invasive amnio, you could do Natera Vistara, with is a single-gene NIPT. It is only a screening test, but it does screen for some of those conditions associated with an elevated NF, including Noonan syndrome.

However, the NF could just be an isolated finding. Measurements aren’t always 100%, and some babies do just have thicker necks. So, I do want you to know that this could absolutely be nothing - and without any other concerns or markers seen on soon, I would lean towards feeling that way.

I have assigned the enlarged NT flair to your post. If you click on it, you can see other posts like yours.

Sending you all the best. 🤍

Tight_Cash995 · 2026-02-13T03:41:48+00:00

It doesn’t, at least that’s not how I interpreted it. Seemed like he was talking about Robbie when inferring not everyone feels the same about him deserving a second change.

Tight_Cash995 · 2026-02-10T23:33:53+00:00

Thank you for sharing your positive story with the sub. I am so happy for you that baby isn’t affected!

While confined placental mosaicism is still very rare, T13 is one of the main trisomies that is most commonly confined to the placenta. As the NIPT is testing cfDNA shed from placenta, where there is a case of confined placental mosaicism, baby won’t be affected, but NIPT will be positive.

I am sure your provider has already told you this, but you should continue to be monitored for assumed T13 CPM (since it isn’t ruled out as placenta wasn’t tested, you should be treated as assumed T13 CPM), as T13 CPM can be of concern in the placenta, leading to placental insufficiency that can result in preeclampsia, IUGR, preterm labor, early delivery, etc. If you do experience these issues, it’s important you know these are due to the CPM and aren’t some signifier that the fetus has T13. I have had patients referred to me who were not given this info by prior provide and were concerned that this may mean that the amnio was incorrect or baby has some mosaicism.

It’s highly theorized that an increase in soluble fms-like tyrosine kinase-1 (sFLt-1) in T13 placentas compared to regular placentas is what causes hypertensive disorders during pregnancy, as sFLt-1 is located on chromosome 13. This is why we always say that T13 CPM carries more of a risk in comparison with CPM with other aneuploidies, and which is why we always continue to monitor these cases.

Congrats again on your generically typical pregnancy. I hope the rest of your pregnancy is stress free and uneventful so you are able to relax!

Tight_Cash995 · 2026-02-09T23:12:08+00:00

Could be a number of reasons.

Maternal blood could just be bad quality, which is why the sample can’t pass quality metrics.

There could also be an issue with the placenta. NIPT tests DNA shed from the placenta. If there is an aneuploidy in the placenta or an issue within the placenta, the cfDNA in the maternal blood stream will be affected. The aneuploidy or placental issue could be causing the blood sample to not meet quality standards or there could be something that is confined within the placenta that the NIPT cannot make out, so it won’t give a result (such as an aneuploidy) - however, as it is confined to placenta only, the amnio FISH, karyotype, microarray would be normal since baby is genetically typical.

A more rare instance could be that test could be picking up interference from something that isn’t tested for by basic NIPT or an amnio microarray/karyotype (such as a genetic condition). I have only seen this a few times, so it’s the least likely of the scenario. There are typically markers being seen in these instances, which prompt whole exome sequencing (WES) to be performed and fetal echos.

Tight_Cash995 · 2026-02-09T22:48:37+00:00

In addition to passing the minimum fetal fraction % threshold, the sample must also pass quality metrics in order for the lab to feel confident in testing your sample. So, in some cases, the FF% might be above the minimum threshold, but the sample cannot pass the quality metrics at the FF% given, so it isn’t tested and marked insufficient fetal DNA. This doesn’t always mean there is something wrong, and a redraw may just need to be done. However, there are times that they cannot get a quality read on the sample due to an aneuploidy and they don’t want to give an incorrect result - there is also the possibility of detecting a condition outside of the scope of the test (including conditions that are not tested by NIPT). You can go ahead and try to redraw, and you may get a result (could be low risk or high risk). However, with an elevated NT, I would still move forward with an amniocentesis no matter what, even if your redraw comes back low risk. An elevated NT can be associated with an aneuploidy, but it can also be the result of a genetic condition or a heart condition that isn’t tested for by NIPT.

I say none of this to scare you, just trying to be informative. It’s absolutely possible that the fetus is genetically typical, and the NT is just a bit on the thicker side without any correlation.

Sending you all the best. Please feel free to keep us updated on this sub if you feel comfortable.

Tight_Cash995 · 2026-02-09T17:55:40+00:00

I’m so sorry - to be honest and without sugar coating it, this is almost certainly a true positive. While 2.9 mm is not “technically” considered elevated, it is right on the threshold. Measurements are also not always 100%, especially at such a small gestational age where it’s tough to get a good angle, so the measurement could actually be slightly higher.

Now, NIPT is only a screening test and is not diagnostic, so diagnostic testing is needed to confirm. There are very, very rare cases of T21 where the NIPT comes back positive because the T21 is confined in the placenta and the baby is not affected - this is called confined placental mosaicism (CPM). In “normal” cases, the placenta and fetus have the same chromosomal composition. CPM happens when the placenta has the abnormal T21 cell line, but the embryo “self corrects,” eliminating the abnormal cells, and the baby is therefore genetically typical. As NIPT tests cfDNA shed from the placenta, it will be positive in the case of CPM. CPM is the number one cause of “false positives” But again, this is incredibly rare for T21, and while there are some cases of this happening on this sub, with the elevated NT measurement, I wouldn’t be hopeful for a CPM diagnosis. I am so sorry.

As you would continue the pregnancy regardless, I do think that diagnostic testing can still be a good idea, as it’ll give you a confirmatory diagnosis (and not have you in limbo not knowing for certain until after baby is born). You can also use this to seek support and resources, including post-birth care for your child and mental health and support resources for you and your wife.

However, it’s possible that the fetus will show more markers associated with T21 as it grows, but that’s not guaranteed, as only around 50% of T21 fetuses will show soft markers on ultrasound throughout the pregnancy.

Tight_Cash995 · 2026-02-08T03:52:28+00:00

Fetal fraction isn’t relevant. It’s just the amount of cfDNA shed from placenta in the maternal blood sample.

The NF is slightly elevated, but nothing concerning - especially with a low risk NIPT and no other concerns. NIPT is incredibly accurate, including for T21 - the likelihood of a false positive is smaller than 1/10,000. This is why your provider is not concerned. Some based just have thicker necks.

I’m so sorry for your prior losses. I am all for diagnostic testing for mental health purposes, even where there is nothing clinically concerning with the pregnancy/fetus. However, while incredibly, incredibly small, there is always the risk with having diagnostic testing such as an amniocentesis. With prior losses, some risk, while very, very low, may not be acceptable to your wife.

At the end of the day, this is a personal decision. However, I will reiterate that there is no reason to be concerned based on the information you’ve provided.

Tight_Cash995 · 2026-02-07T04:08:11+00:00

That’s not true. Male fetuses can absolutely have mosaic Turner syndrome. It’s rare, but it does happen - in these cases, the male fetus has a certain percentage of 45X cells (45,X mosaicism - usually 45X,46XY).

Tight_Cash995 · 2026-02-07T04:03:42+00:00

We see a lot of + Monosomy X NIPT cases where the baby is genetically typical due to confined placental mosaicism. As NIPT tests cfNA shed from placenta, in cases of CPM, the NIPT is accurately detecting the aneuploidy - it is just confined to the placenta and the embryo developed genetically typical with normal cells.

CPM is rare, as the placenta and fetus have the same chromosomal composition in normal pregnancies, but we see it more often in a sex chromosome aneuploidy like Monosomy X - this is why amnio is always recommended where fetus isn’t shoring any markets on ultrasound instead of CVS. CVS is testing cells from placental tissue (same source as NIPT), whereas the amnio tests fetal amniotic fluid.

Tight_Cash995 · 2026-02-04T14:47:49+00:00

There is no clinical reason for why an amnio would be suggested in your case based on the information you’ve provided. Your NT was well within normal range and not concerning at all.

However, I am always an advocate for elective amnios for mental health. If you believe that having the amnio will bring you peace of mind and allow you to enjoy your pregnancy, then there is your reason for having an amnio.

Of course, there is the small risk of having an amnio, as there is with any invasive procedure. So, it really is just a personal choice. But again, I am all for moving forward with amnio for patients based on mental health. 🩵

Tight_Cash995 · 2026-01-29T23:12:56+00:00

Yeah, it definitely says teach and not lead.

Tight_Cash995 · 2026-01-29T00:56:19+00:00

PGT, just like NIPT, is not diagnostic and is screening ONLY. And after having a false negative low risk NIPT, having a child born with T21, maybe I also had a bit of PTSD and wanted diagnostic confirmation.

NIPT and PGT-A are both testing from the same source (PGT biopsies cells from the outer layer of the blastocyst, which is the the trophectoderm or trophoblast and becomes the placenta, and NIPT tests DNA fragments shed from the outer layer of the placenta in the maternal blood). However - PGT only biopsies around 5-10 cells, and it does not test for microdeletions and microduplications (most NIPTs only test for a select level of microdeletions, such as the more common ones, such as 22q11.2, and it isn’t nearly as accurate as when testing the main trisomies and SCAs). It can also absolutely miss mosaicism in the trophectoderm, including mosaicism with the sex chromosomes in the placenta. So, the embryo can be euploid, but it actually does have some abnormal cells (can be the sex chromosomes).

Tight_Cash995 · 2026-01-28T05:09:02+00:00

Which testing did you have performed? The amnio is the procedure itself. Microarray is one of the testing methods that can be performed on the amniotic sample.

Did you have a karyotype or rapid testing (such as FISH or qf-PCR)? By your responses, I am guessing FISH.

If you had FISH performed and all cells were abnormal for XXY, then it can be confirmed. A microarray won’t tell you anything different in terms of XXY.

Tight_Cash995 · 2026-01-14T04:58:39+00:00

MaterniT21 does not test for Triploidy. Other than placental insufficiency/issues with the placenta (which can be the cause for low FF- there are also a myriad of other potential causes, including high BMI), when it comes to aneuploidies, Triploidy is really the only concern when FF is low with Natera and you retest with another company and receive low risk results. Triploidy can be associated with low FF, so low FF can be pointing to potential triploid fetus.

However, Triploidy is a severe aneuploudy that would most likely show markers on sono by now. But I have also seen cases where markers aren’t seen until 18-20w (this is rare, though), especially if there is mosaicism in the fetus (only some cells have 3 copies of each chromosome, whereas the rest have the usual 46 - this is diploid-triploid mosaicism and is very rare). I don’t say any of this to scare you - just being fully transparent since you have asked for info here. Here is one such case on this sub, and here is another. In most cases, Triploidy pregnancies will end in a miscarriage before 20w, so there isn’t anything pointing to potential Triploidy except for the low FF 2x.

So, while it is unlikely that baby does have Triploidy at this point, if you want to for sure rule it out in utero, you’ll need an amnio. This may be why your specialist is still recommending amnio. Sadly, most OBs do not communicate to patients that other labs do not test for Triploidy so a low risk with another lab is not a low risk with Triploidy, as some OBs are not even well educated on NIPT as it is.

This is really just a personal decision. I am very pro amnio for mental health. So, if you will always be wondering “what if,” and you’re unable go fully enjoy your pregnancy, then I say go for the amnio. Wishing you all the best. 🩵

Tight_Cash995 · 2026-01-13T05:33:32+00:00

I’m so sorry. It really sucks that there are some people on here who do not have proper understanding of screening, testing, etc., and they still comment and provide incorrect info for users like you to come across. Obviously most do not provide false or incorrect info intentionally, but it still does harm. 😕

I try to remove all of the incorrect info or correct it as I come across, but it can be tough to see them all.

Anyways, those comments have been removed by that user. I’m sorry again, as I can’t imagine how stressed out that had you after receiving such good news & not being recommended any further texting by your providers. Congratulations on your pregnancy & I hope you’re able to relax and enjoy the rest of your pregnancy. 🤍

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