NT scan vs. prenatal blood screening

[Deleted]

So my doctor said I can have the option of one of the other. I am not high risk (33 yo) but the NT scan is done by the in-house sonographer, which I don't really like. I think she is pretty inaccurate and she always seems like in a hurry. Last time, she told me that the blood work (pin prick) with the NT measurement is 99.9% accurate. I know I'm being picky about this because I'm an engineer but I don't like it when people just throw numbers out there. Also, she never caught dd's club foot at the anatomy scan. This time, I'm seeing a specialist for a more detailed anatomy scan due to increased risk. 

So if I go for the NT scan, we can do it this Friday and get to see the baby, but it's with the sonographer I don't like.

Fetal blood screening- more accurate, but don't get to see the baby. Insurance won't cover it but I called the company and they said it would be a max of $99 oop.

The chance of a false positive is higher with the NT scan, right. 


WWYD?

[Deleted]

Jul 7, 2015 13:38:54 GMT -5 @littlemoxie said:

1. NTs don't give "false positives" they give you odds.

2. If accuracy is your concern, do the blood screening. This is about medical care, not seeing the baby.

Oh, that's right. My mistake.

[anna7602]

My insurance covered both because I am AMA. The NT scan actually showed high enough odds of something that they reco'd an amnio. When they realized I'd already had the verifi, they realized that I didn't need an amnio at all. The Verifi results were more accurate and reliable.

So, if I was only going to get one, I would get the blood test. Won't you get a 20w anatomy scan anyway?

[Deleted]

The scan isn't as accurate as the bloodwork. I know the desire to see the baby, but for the right information - I'd go bloodwork.

ETA - FWIW, my NT scan pictures sucked. My AS pics were way better.

ETA2 - Fixed my orignal post to say what I meant which is that the bloodwork is more accurate than the scan. Thanks for calling me out, teatimefor2

[rosiedozie]

I was given the same option and chose the Panorama test. I'll have to wait until 14 weeks until we get to check on the baby (via Doppler) and likely won't have another u/s until my anatomy scan.

[konapoppy]

Jul 7, 2015 13:43:18 GMT -5 @tambcat said:

Is the blood work the standard first tri screen or one of the new tests (materniT21, panorama, etc)? If it's just the standard, I wouldn't pay OOP, and I don't think it has a higher rate of catching anomalies than the NT scan. I know she said 99%, but is that in conjunction with the NT scan? (fwiw, i don't think it's 99% together either).

If it's one of the newer tests, I'd probably pay the $99 OOP for that.

I am going through this myself and having gotten the standard blood work, I wish I had just done a cell free DNA test like materniT21. I think the odds have created unnecessary worry, and I wish I had done a blood test that would have be more conclusive. 

[teatimefor2]

Jul 7, 2015 13:43:28 GMT -5 @sessalee said:

The bloodwork isn't as accurate as the scan. I know the desire to see the baby, but for the right information - I'd go bloodwork.

ETA - FWIW, my NT scan pictures sucked. My AS pics were way better.

This is not accurate. The scan is looking at the fluid in the neck flap which is usually under 3mm. However this is a soft marker and the blood work is critical. The blood work is essential.

The nose bridge, which is looked for in the US, isn't even considered a soft marker is most western countries.

OP, personally, if it's piece of mind if request T21 blood test and lay the OOP fee of $99 as long as you can afford it.

[Deleted]

Jul 7, 2015 13:56:27 GMT -5 teatimefor2 said:

Jul 7, 2015 13:43:28 GMT -5 @sessalee said:

The bloodwork isn't as accurate as the scan. I know the desire to see the baby, but for the right information - I'd go bloodwork.

ETA - FWIW, my NT scan pictures sucked. My AS pics were way better.

This is not accurate. The scan is looking at the fluid in the neck flap which is usually under 3mm. However this is a soft marker and the blood work is critical. The blood work is essential.

The nose bridge, which is looked for in the US, isn't even considered a soft marker is most western countries.

OP, personally, if it's piece of mind if request T21 blood test and lay the OOP fee of $99 as long as you can afford it.

Blargh. I got halfway through a sentence and got distracted and changed direction. I did mean the bloodwork was more accurate. I'm sorry. Will edit my post.

[Velar Fricative]

Blood test. No question.

[Susie]

I just did the NT scan and triple screen blood tests; I did not do MaterniT21, Panorama, etc. I'm also 33. If my NT/triple screen results had come back anything but low/normal level of risk, I might have pursued more expensive/OOP cff DNA testing, but they didn't.

In related news, in a recent decision the Fed. Cir. invalidated a Sequenom patent covering the MaterniT21 test. I am curious to see how/if this affects cost and accessibility.

www.personalizedmedicinebulletin.com/2015/06/30/federal-circuit-invalidates-another-diagnostic-patent/

patentlyo.com/patent/2015/06/sequenom-subject-eligibility.html

[barefootcontessa]

I would probably do the NT scan + associated blood work because it tells you more information. The T21 just screens for the three chromosomal abnormalities, while the neck fold measure also correlates to congenital hearts and maybe some other things. What does your OB recommend?

[Deleted]

Jul 7, 2015 14:02:40 GMT -5 barefootcontessa said:

I would probably do the NT scan + associated blood work because it tells you more information. The T21 just screens for the three chromosomal abnormalities, while the neck fold measure also correlates to congenital hearts and maybe some other things. What does your OB recommend?

My OB recommends the NT because I am not "high risk" so a part of me feels like it's kind of overboard to push for the blood test. She did mention that the Verifi test would not screen for something like dd's club foot but we are having a detailed anatomy scan anyways.

[runblondie26]

I would go with the bloodwork if you have to choose one or the other.

However, I'm surprised they still wouldn't do the NT scan in conjunction. At both practices I used, it was standard to have both even with one of the advanced cell-free DNA tests. The ultrasound can pick up other physical ananomolies the blood tests miss, and is relatively easy and non-invasive to do.


ETA: Ok, I see in your follow-up posts you would get the quad-screen bloodwork with the NT scan. I'd choose that over a cell-free DNA test and no ultrasound.

[h]

I was given the either/or option and did the blood test.

[raangoli]

Jul 7, 2015 14:06:54 GMT -5 gravytrain225 said:

Susie Can you describe your last sentence for those of us who don't understand? lol

I believe it means that other labs can offer the test and thus potentially lead to it being lower cost/more accessible.

[starlily]

Jul 7, 2015 14:25:14 GMT -5 h said:

I was given the either/or option and did the blood test.

Ditto.

[mae141]

Why can't you get both? I had both for two pregnancies and am not AMA. If I had to pick one I would go with NT because Verifi and the others only check for a few things and the NT could catch more.

[D2M]

My only hesitation with just doing something like the Materniti21 test is that it has a higher incidence of false positives, according to a series my friend sent to me recently (it's on my mind, too, because it's covered for me this time around). The article was done by the New England Center for Investigative Reporting, so not a muckraking outfit. If the test comes back positive for something, I'd want additional screening, anyway.

[Susie]

Jul 7, 2015 14:06:54 GMT -5 gravytrain225 said:

Susie Can you describe your last sentence for those of us who don't understand? lol

I haven't read the decision in its entirety yet, but the basic gist is that Sequenom patented their method of prenatal diagnosis using cffDNA, embodied in the MaterniT21 test, and then threatened to assert the patent against Ariosa (i.e. sue them for patent infringement).  Ariosa makes Harmony, a competing test.  A long series of legal procedure happened, and in June Sequenom lost their appeal to the Fed. Cir., which is the court of last resort for patent matters unless SCOTUS grants cert (which I think is unlikely here).

So as things currently stand, Sequenom can't exclude other companies from using their patented method, because the patent is invalid.  This tends to increase the number of generic entrants into the market, and push the price down.  They can still make and sell the MaterniT21 test, but others can make the same test, market under a different name, and compete for market share.

It's basically the same scenario as when the patents covering a drug expire (like for Ortho Tri Cyclen, or Lipitor to name a few big sellers that have gone off-patent), except it happens "early."  Generics flood into the market and now the brand name has to compete on price and to whatever extent they can rely on brand recognition.  Anybody who used to use Ortho Tri Cyclen for BCPs knows how willing insurance companies are to pay for the name brand when a generic is available for less.

[Velar Fricative]

Jul 7, 2015 14:02:40 GMT -5 barefootcontessa said:

I would probably do the NT scan + associated blood work because it tells you more information. The T21 just screens for the three chromosomal abnormalities, while the neck fold measure also correlates to congenital hearts and maybe some other things. What does your OB recommend?

This depends on the test. The one I had done (Panorama) tested for more than the usual three chromosomal abnormalities. It detected the microdeletion my baby had (though, since it's a screening, it didn't come up "positive," just gave me higher odds and the amnio confirmed it along with other issues that went undetected by the test and by the NT scan and quad screen). 

[gingerjar]

Personally I would do the blood test and pay the $50
Or so rate to get an elective ultrasound just to see the baby.

[Yankees21]

Jul 7, 2015 15:01:36 GMT -5 @tambcat said:

Tangent alert - I hate when the desire to see the baby is brushed off as frivolity. Even when not medically indicated (which the NT scan is), ultrasounds can provide peace of mind for some people beyond hearing a heartbeat on a doppler. Ensuring maternal comfort and reducing maternal anxiety are important to me. I am an anxious person and felt a sense of relief every time I saw a little baby floating around on the screen. Some people want limited intervention during their pregnancies, but I would have been in the doctor's office everyday at the beginning if I could have.

Yes. I would probably do both since it sounds like one will be covered and one OOP, but I did get a lot of comfort from seeing the US.

[Poppy]

As someone who had an NT that was screen positive with abnormality confirmed by CVS, I opted for both NT and blood test for my next pregnancy.

If I *had* to pick one, I'd probably go for blood test if it looked for more than the three trisomies. I'm not up to date on which ones do or don't.

But I'm with @callmefia. If you're OOP for the blood test anyway, I'd ask to do both.

[chickadee77]

I would do the bloodwork for sure, since when I went in for one of my prgnancies, I was told everything looked "fantastic" at the NT u/s, then got a positive M21, confirmed by CVS.

However, my OB is awesome and will do an u/s at mother's request, as they realize how important mom's gut feeling is, and how critical peace of mind can be.

So I realize my opinion is colored by my personal experience.

[Deleted]

I would do both. I've had two issues spotted at NT scans that required follow up care that wouldn't have been caught with just the genetic test.

[curbsideprophet]

I only had the blood test with DS. No regrets. My midwife mentioned that she thought the blood work could start to replace the NT scan.