Bad advice from ob re: screening?

danuli8 · September 2012

Happy Friday, everyone! Please excuse the long post, but I could really use some advice from the more experienced folks here.

This is my first pregnancy ever. I am almost 10 weeks along now and setting up my prenatal screening. I decided to do two things: the first-trimester NT ultrasound + blood screen and the MaterniT21 blood test. My ob says I don't need to do both. I disagree, but maybe I don't understand how the first-tri screen works. Here's my understanding: you start out with certain "odds" of abnormalities based on your age. My odds are kinda iffy because I am 41 and will be a month past my 42nd birthday at my EDD. Then they take the results of the NT AND the blood screens (PAPP-A and HCG) and use those to "modify" your odds up or down. So you might start with odds of 1:86 (I think that's my number), and based on the screen and bloodwork, get better odds of, say, 1:250, or "worse" odds of 1:12. Have I got that right? Anyway, I think playing the odds is ridiculous. It's not great data. So I ALSO want the MaterniT21 test, which is 99.5% accurate on telling you if you have trisomy 13, 18, or 21 (and as a bonus, they now also tell you the sex of the baby!). I figure if I get bad "odds" from the first-tri screen, the MaterniT21 test can reassure me, or, if it gives me a positive result, I can do an amnio to confirm.

I am trying to avoid an amnio if possible. I figure two different pieces of data, at least one of which is reassuring, would be enough for me to skip the amnio. Is my reasoning sound? I'd really appreciate some advice/opinions here. Thanks!

uctracy@yahoo.com · September 2012

I did the NT scan + blood test and MaterniT21 test. All of them confirm the findings and hopefully prevent you from having to have a CVS or Amnio when everything looks good.

pillowass · September 2012

I think your plan is totally reasonable. Both tests are non-invasive and pretty much risk-free, so as long as you or your insurance is willing to pay for them I can't imagine why the objection.

technigirl · September 2012

When I had my daughter, the MaterniT21 test wasn't available, so I did the NT scan + bloodwork. I decided against amnio since the NT + bloodwork showed my odds of having a baby with a problem were low.

With the MaterniT21 being so much more accurate than the NT scan/bloodwork that was available before, I can see why your provider might suggest that you skip the NT + bloodwork and just go for the MaterniT21. i.e. if you were sure you wanted an amnio, they would advise you to skip the NT scan, because what's the point?

With MaterniT21 being so new, maybe it is a good idea to get both though, if you can. Plus, you get that bonus ultrasound with the NT scan - another opportunity to see your baby. I can see where the docs and insurance companies wouldn't approve of it solely for that reason though.

Melissa

StaceySMC13 · September 2012

I did the NT scan first and was told my risk for down syndrome was 1/70 (lower than my age risk). The genetics doc said though that if they decrease your risk, you still should go by the highest one since that truly is the chance you have of abnormalities.

Once I got the 1/70 risk, I did the MaterniT21 test. Had I known better, I would have skipped the NT scan and just done MaterniT21. I was stressed for too long waiting for all the results.

I just had mine done in June and they said they could not tell me the sex of the baby. Has it changed since then?

benoitfan · September 2012

You understand the nature of both tests. The Materniti21 test is not available here. I elected to do the Integrated Prenatal Screening (NT scan, 1st tri blood work the day of the NT scan and a 2nd tri blood draw at 16w).

My odds before the test based on my age was 1:82 for Downs and 1:53 for any trisomy. When I got the results back at 16w including my NT and blood results were less than 1 in 100,000 for any trisomy. Based on those results I would not have done the MaterniT21 test even if it was available to me. Had my numbers been screen positive (greater than 1 in 200 for downs or greater than 1 in 100 for other trisomy), I would have elected to have an amnio.

Don't let your doc bully you. If you want both, do both, no harm done.

mrsjami · September 2012

just skip the NT and go straight to materniti21. That one is actually diagnostic.

uctracy@yahoo.com · September 2012

StaceySMC13:

I just had mine done in June and they said they could not tell me the sex of the baby. Has it changed since then?

They are able to determine the presence of Y chromosomes which would indicate you are having a boy. If you don't have Y chromosomes it indicates you are having a girl. My doctor asked me if we planned to know the gender. When I said yes, he told me. Your doctor should be able to review the results and let you know if there were any Y chromosomes identified. According to my results, I am having a girl...needless to say, I am waiting to do the anatomy scan before I decorate the room. Smile

simplein06 · September 2012

I would speak to a genetic counselor, before you make your decisions. I found the GC a wealth of knowledge and as a result I was able to make much better decisions

stever · September 2012

I would do one or the other. Neither give you definitive answers, just odds. With both my prenancies I did the NT then AFP and would have moved onto an amnio if my numbers were dodgy. Same deal if I had the MaterniT thing.

danuli8 · September 2012

Thanks for all the great input, everyone. I really appreciate it. I guess I want the NT scan because it's another chance to see the baby, and who knows, I might end up with really good odds. But I also want the MaterniT21 because it is basically a diagnostic and not a screen, so the results are solid, not guesses on what MIGHT happen. And I admit I would like to know the baby's sex. (They just started offering that at the beginning of September, I think, so it is very new indeed.)

mysticriver · September 2012

As is my understanding, the MaterniT21 is also just odds. They're more accurate odds, but they're still odds, not a definite yes/no for chromosomal abnormalities. After discussing this all with my genetic counselor it's why I decided to skip the test and just stick with the NT - we would have had to pay out of pocket, and I didn't think it was worth $500 for something that still wasn't definitive and would have to be confirmed by CVS/amnio anyway. If you have great insurance coverage, though, go for it.

danuli8 · September 2012

mysticriver, I did some more reading and you are right--the MaterniT21 is also just odds--but vastly more accurate odds than the NT+bloodwork. If it gave me a negative, that would be reassuring enough for me to skip the amnio.

I am happy to say that my OB's office called again today (after I let the assistant know I wanted both tests, and why I wanted both) and said they will do the MaterniT21 blood draw at her office the day of my next regular OB app't--which happens to be at 12w1d, so that should be late enough to get a good sample for testing. I have to pay for the MaterniT21 test myself, and the cost would range from $235 to $465. But if it means I can avoid an amnio it's worth it.

Want a personalized experience?

Bad advice from ob re: screening?

Re: Bad advice from ob re: screening?

Choose Another Board

Search Boards