Genetics Disorder Test

I took a genetics risk test and all we got back was a 1 in 135 and were told it is high risk. Does that really mean a 1 in 135 chance of having a genetics disorder. That seems to be a really low chance but I guess if you compare it to a normal 1 in a 600 for my age It is not. Unless I misunderstood it all. I guess I am asking what it means and if you feel like sharing your results what were they at 14 weeks or so!!!

 

I refused the test. They say with twins the numbers are way off anyway.

 

My ob doesn't give that test with multiples. Too much chance of false positives.

 

We had to have genetic counseling due to my age of 33 while preg with the boys. I asked about the quad screen to the counselor and had her call the lab about the false positives. I dont remember the percents anymore, but for the Downs marker with twins it was only like 25% accurate and it went downhill from there for the others. So we declined it. My Peri wanted me to get it just to see what the numbers would be, but I never did. I would ask your OB to put it in perspective for you.

 

I'm 34 and we skipped the AFP screen as well. My doc didn't think it was worth it with multiples. He said the nuchal ultrasound screen was much better.

 

Sorry, i'm not any help. We also declined the screenings due to false positives and such. I would say just ask the doctor to explain your numbers to you and what he/she thinks they mean or could mean next time you go in. Good Luck. Hope you have a happy and healthy 9 months.

Melissa

 

Are you talking about the nuchal translucency test (u/s) combined with the bloodwork? If so, yes, the number they gave you is a 1 chance in 135 that your baby COULD have a genetic problem - Down syndrome most likely. (I think they lump in other chromosomal abnormalities, like trisomy-18, but D.s. is what everyone refers to because the occurrence is much higher than the others.)

You should get in touch with a genetic counselor. They should not have just done the test and given you a result and left you hanging. The g.c. can tell you exactly what was done, what your numbers mean, and your options from here.

We had the tests done, and our results came back 1:23 for Down syndrome on Baby B. So we had a CVS test done. (It's too late for you, at 14wks to have done. You'll need the amniocentesis instead if you choose to have more testing done.) The results for the CVS came back that both babies are perfectly FINE! There is no D.s. showing up in their chromosomes. So we worried for nothing.

I agree with other posters that the results of the early tests, particularly bloodwork from you, are inaccurate with multiples. If I ever wind up pregnant again (with or without multiples), I will NOT be getting the tests.

Good luck finding out more information!

 

Hey,
I am a genetic counsellor. I obviously can't counsel you over the net, and I am missing some vital information, but I can tell you that what the ladies have said is correct!
Twin pregnancies give often false positives. What the Drs are measuring are some proteins in your blood that you only have when you are carrying a baby. They can be normal range or higher or lower and some people worked out that if the numbers are off (some are higher and some are lower) your risk of a genetic problem (and yes mainly Down syndrome, but also trisomy 13 (Patau syndrome)and 18(Edward's syndrome)) is higher. They give you a risk assesment which means they tell you at your number how many women have an affected baby (so for example 1 in 600 would mean that of 600 women who had that test and got the same exact number 1 had a child with a genetic syndrome). These proteins however are known and studied in people who carry 1 baby and not too much work has been done on twins, which is why they are often off in twin pregnancies.

If they did a nuchal translucency test (which they do for each baby on their own) combined with blood work then the numbers may be correct which would mean that of all women who have your numbers 1 in 135 has an affected baby.
This is considered high risk (generally 1 in 150 and more is considered high risk) and they will probably offer you invasive testing, which at your gestational age would be an amniocentesis. That means that they will take some fluid from around the babies and send it to a lab. You should know however that 1 in 100 of those (independently if affected or "normal") will miscarry. With twins actually it is even higher because you poke the tummy twice, which means you have a higher risk, I would say about 1 in 80. Once you miscarried one it is more likely that you micarry the second one too, since your cervix will be open and your uterus will be sensitive.
Personally I cannot tell you what to do, but I think you should keep those numbers in mind and remember that of all women with your blood numbers 134 out of 135 have a healthy baby!

Have your Ob explain it properly to you or see a genetic counsellor on site, they will explain it in more detail than I could over here, and do not let them push you. This is your decision and your babies.
Love, Millie

 

After hearing that the tests are not as accurate with multiples, I, too, refused. I did not want to be worrying about another what if, if I didn't have to. KWIM?

 

What test did you have? The ones that involve blood work are not as accurate for twins. I had the NT scan, but w/out the bloodwork portion. Sofia came back as a 1 in 249 risk for Down's, but I refused the amnio. I was scared, but she ended up being fine! I also found out that they take 3 measurements and use the highest one. So, I actually had 2 normal measurements, and 1 that was a little high. I was pretty much worried for nothing.

 

I had the nuchal translucency test combined with the blood work for each baby. My results were something like 1/2864 and 1/2857 at 11.5 weeks.