Gave blood for my MaternT21 test
danieleandwayne
member
Had a very enlightening conversation with the genetic counselor who put to rest the way the MaternT21 test is determined positive or negative. For anyone who is interested, I can report intelligently on it since it was a whole lot of confusing until the counselor looked it up and was able to explain it to me in real language.
Anyhow, I will now have to wait 2 whopping whole weeks to get the results. And I won't get to see them (which is fine) because I don't want to know the gender of our baby until it exits my body.
Hopefully, everything will come back negative. If anything is positive, I'll have to get an amnio, which I was trying to avoid in the first place. Nothing to be done at this point, anyhow, so I'm going to look forward to my next OB appointment on Friday!
<br /> My Ovulation Chart</a>
Re: Gave blood for my MaternT21 test
My heart is as open as the sky.
Read about it on the blog
2 Corinthians 12:9 But he said to me, "My grace is sufficient for you, for my power is made perfect in weakness." Therefore I will boast all the more gladly about my weaknesses, so that Christ's power may rest on me.
Anyhow, the MaterniT21 test is determined based on standard deviation, for the most part. So they take all the baby's genetic material floating around in your blood and then sort the bits (kind of like if you shredded a document typed in 25 languages and then took the shredded bits and put them in a pail, sorted by language). If you have more chromosome 13, 18, or 21 bits, then your baby has a certain likelihood of having those trisomies. They take a line and put it through the average number of chromosomes found in blood samples taken from tons of women and call that line "zero." Then, if you have a certain number of chromosome above that zero, you get rated +1, +2, +3, and +4 with the higher number of chromosomes above the norm getting a higher rating. For MaterniT21 purposes, you get a "positive" for the trisomy for the chromosome if you have enough extra of that chromosome above the normal amount to give you a rating of 3 or 4. If you don't have enough to get you a 3, then they report a negative because they only report 99.2% likelihood, which they can only be certain of if you have enough extra chromosomes.
For DS, it's 99.2%. For Trisomy 13, it's like 91% and for Trisomy 18, it's something like 94 or 95%. But in order to be in that percentage to be considered positive for that trisomy, you have to have 3 or 4 standard deviations above the normal amount of that chromosome. And that norm is not determined by age at all. It's from all women of all ages.
That sounds like a lot of confusion. Does it make sense to you?
Also, if it makes you feel better, nowadays there is less of a stigma for Downs kids and they get help and resources way earlier. So many of them-- the vast majority, in fact-- go on to live independently or in group homes and hold down jobs. My friend's brother is in his late 50s and has a job and lives with his girlfriend who is also Downs. And he didn't have the advantages that this generation has...
<br /> My Ovulation Chart</a>
My heart is as open as the sky.
Read about it on the blog
2 Corinthians 12:9 But he said to me, "My grace is sufficient for you, for my power is made perfect in weakness." Therefore I will boast all the more gladly about my weaknesses, so that Christ's power may rest on me.
Over-40 parents...what we lack in vigor, we make up for with cunning.
Thanks Daniele! I've been wanting to learn more about this test...it wasn't offered when I was pregnant with my daughter a few years ago.
DD born 12.21.09, conceived w/ injects and IUI
TTC#2 since Nov 2011
BFP 2.6.12 m/c 6w5d | BFP 5.25.12 c/p
-Back to the RE-
3 medicated IUIs, all BFN
-Taking a break from treatment-
BFP 11.20.12 ~ EDD 7.28.13
My Chart
I hope you get great results! That is interesting, I never really knew how it was calculated.
BFP #1 - missed m/c 4.18.11 found @8w3d, d&c @13w
BFP #2 blighted ovum found 8.2011 @8w, misoprostol
BFP#3 - missed m/c 6.11.12 @ 9w3d, d&c revealed extra chromosome 15
BFP#4 8.10.12, DD born 4/26/13
Thanks for the info. I had it done and got my results already, but they didn't explain the particulars. I was negative and found out we're having a boy (I wanted to know).
Melissa
Good info! Isn't it amazing how low the % chance is yet somehow I feel like we're made to feel like it's almost inevitable!
Me 41 DH 46 Not actively ttc, surprise BFP on 1/6/11! 4/1/11 m/c our sunshine at 16wks after complications from CVS test. TTC #2 **5th cycle 12/6/11 BFP! Missed m/c at 9 weeks 1/21/12, trisomy 14. Two Chemical PG 3/12&7/12
** BFP 8/16/12 beta #1 148! beta#2 407 beta #3 4000 u/s 9.10 1 lovely hb 126, Baby Boy is due 04/28/13!!
This! I mean, my LO has WAY less than a 1% chance of having trisomy 13 or trisomy 18 and a slightly less than 1% chance of having DS-- but it feels like I'm going to win the lotto if my results are negative!
Crazy...
<br /> My Ovulation Chart</a>