View Full Version : If this is true...

April 22nd, 2013, 06:56 PM
Then how can the harmony with Y chromosome analysis(and others like it) be accurate??


April 22nd, 2013, 07:15 PM
I think they quote a 5% false positive rate. So, there is a chance that the Y from a past pregnancy shows up, yes.

April 22nd, 2013, 07:19 PM
The Materni21 site quotes a 99.4% accuracy for Y chromosome. There is always room for error. How far along are you? Did you have a NT scan too?

April 22nd, 2013, 07:29 PM
I was 14 weeks when the blood was drawn for the test, it took them 3 weeks on the gender part for reasons they wouldn't say, the other chromosome abnormalities was done in a week and were normal range, they don't do the nuchal scan anymore because this harmony test replaces it and supposed to be more accurate then trusting an u/s tech, I wil get an anatomy scan 18-20 weeks(I am 17 weeks now) so I am pretty sure they are right I am having my 5th boy just wondering if that article is true then how they tell if the Y chromosome is for this pregnancy and not from having boys?

April 22nd, 2013, 07:50 PM
I don't know how they sequence the DNA but I know the Y chromosome is the most difficult to do because there are very few in your blood and it is very small.

I did find this to give you some hope that it is wrong-

As time went on, more and more medical scientists confirmed the fact that fetal cells do, indeed, appear in most women during and after pregnancy. In fact, one study showed that for some women, the fetal cells stayed in the mother for as long as 27 years after the baby was born!2 In other words, motherhood can affect women on a cellular level long after the child has left home!

April 22nd, 2013, 07:58 PM
What throws me is my sister is having a boy too and her test only took a week, same office, same lab, I want to know why it took so long for mine lol but I will never know, maybe because they were capable of pulling the old Y chromosomes out and were trying to find for this pregnancy lol and that's what took so long,

April 23rd, 2013, 04:12 PM
I live in Los Angeles and went to the supposed "best" perinatologist for our NT scan and they told me they stopped using 'Materni21" b/c of incorrect gender results so they switched to Harmony for the diagnostic testing(which did not yield gender results at the time) Not sure how much truth there is to the inaccuracy but that is what I was told...

April 24th, 2013, 02:30 PM
Well I guess I can hope but not hold my breath lol

April 24th, 2013, 04:35 PM
This is how I understand it:

Yes, intact fetal cells may still be present in your body from past pregnancies. These are not the cells they are testing. They test free floating cell free DNA...which is different than intact cells. There is a surface protein on intact cells. The free floating cells are removed from your body in the days after birth.

I would trust your results. If they were testing the "wrong" cells, thousands of women would have false results but they are not. The test is 99% accurate, and in my mind if a Y is found, its pretty much 100%.

I hope you find peace with having a 5th boy. FWIW, I think you are a lucky lady, although I know it must be difficult if you had your heart set on a girl. I hope you are able to enjoy the rest of your pregnancy and get excited for your new little man. ((hugs))

April 24th, 2013, 07:42 PM
Well there is that chance of a vanishing male twin haha ;) no I am pretty sure they are right because I can't find anything where they were wrong on the Y analysis and if they were wrong I am pretty sure people would be a griping and google would pick it up lol

Anyway I found this article it goes into more details for you smart people interesting in knowing more about fetal cells staying in you for decades later (this article goes way over my head lol)
Cell Migration from Baby to Mother (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2633676/)