Quad Screening & twins

KozieKim

Did anyone have a quad screening done? I have read that the false postitve goes up for multiples and/or date issues.

New to the multiples board too! Hello all

Kim 

CardsfanSM

At the advice of my OB, we are not doing the quad screen.

KozieKim

Did they recommend any screening? Mine is pushing the amnio which I am not comfortable with. I turned 35 in January and feel its just a number..I am in good health with no genetic problems in the family. Just dont know what to do.

CardsfanSM

No, OB isn't pushing anything except NT scan and I wanted to do that anyway. I'll be 37 in May.

Shelley-Bean

I did it, and they adjust the normal ranges for twins.

smeyer

Shelley-Bean:

I did it, and they adjust the normal ranges for twins.

This.  We did the quad screen and an NT scan.

babya2010

MrsLee04:

My OB discouraged it, so we didn't do it.

This. We weren't offered the NT scan either, not sure why.

Kristen61607

we didn't do any testing like that - NT, quad, etc. It wouldn't have changed our minds about anything so why bother. My OB was fine with that decision. Oh, and I'm 25 if that matters.

amanda31H

I had one and got a false positive.

I was not aware AT ALL that they are common with multiples.  Had I known what I know now, I wouldn't have had one.  My doctor didn't push me to get one, but also didn't explain that with multiples the results can be skewed.  We have since decided that on other pregnancies we will not do any genetic testing.  The whole experience was incredibely alarming and traumatic. 

E&RMommy

The quad form that is sent with the blood work has many pieces of information (mom's age, weight, singleton/twin, ethnicity) that are used to formulate the risk calculation.

Although false positives are greater in multiples, it does not mean the test is inherently flawed for everyone.  You have to understand it's just a risk calculation singleton or not.  A negative screen does not mean there are no defects just as a positive screen does not mean defects are present.  More likely than not, a twin mom will still have a negative screen. 

Here is ACOG's stance:

Serum screening tests are not as sensitive in twin or triplet gestations, in part because data from multiple gestations that include an aneuploid fetus is so scarce that expected analyte levels must be estimated by mathematical modeling. In addition, analytes from both the normal and the affected fetuses enter the maternal serum and are in effect averaged together, thus masking the abnormal levels of the affected fetus. In monochorionic twin pregnancies, the median nuchal translucency values are larger in 38% of twin pairs destined to develop severe twin?twin transfusion syndrome (43). Furthermore, counseling is more complex because women must consider a different set of options in the event that only one of the fetuses is affected. Nuchal translucency screening in the first trimester with the option of a CVS and earlier selective reduction may be desirable for some women. Experience is limited with triplet gestations, but studies suggest that nuchal translucency measurement is feasible. Until further studies are done, however, risk assessment in multiple gestations should be performed judiciously, and patients who are at increased risk of aneuploidy should be counseled regarding diagnostic testing.

It all boils down to if knowing makes a difference.  For me, I was only concerned about Trisomy 21 because there is a higher risk of cardiac anomalies, and I would want pedi cards readily available at delivery.  For Trisomy 13/18, I'd want to know in order to be prepared for a child who would not likely live.  For a neural tube defect, there are emerging surgeries that can be done to correct them in utero.

I would have rathered risked a false positive test and need an amnio than risk not knowing.  Everyone is different!!   

AFaul

Shelley-Bean:

I did it, and they adjust the normal ranges for twins.

This

amanda31H

E&RMommy:

The quad form that is sent with the blood work has many pieces of information (mom's age, weight, singleton/twin, ethnicity) that are used to formulate the risk calculation.

Although false positives are greater in multiples, it does not mean the test is inherently flawed for everyone.  You have to understand it's just a risk calculation singleton or not.  A negative screen does not mean there are no defects just as a positive screen does not mean defects are present.  More likely than not, a twin mom will still have a negative screen. 

Here is ACOG's stance:

Serum screening tests are not as sensitive in twin or triplet gestations, in part because data from multiple gestations that include an aneuploid fetus is so scarce that expected analyte levels must be estimated by mathematical modeling. In addition, analytes from both the normal and the affected fetuses enter the maternal serum and are in effect averaged together, thus masking the abnormal levels of the affected fetus. In monochorionic twin pregnancies, the median nuchal translucency values are larger in 38% of twin pairs destined to develop severe twin?twin transfusion syndrome (43). Furthermore, counseling is more complex because women must consider a different set of options in the event that only one of the fetuses is affected. Nuchal translucency screening in the first trimester with the option of a CVS and earlier selective reduction may be desirable for some women. Experience is limited with triplet gestations, but studies suggest that nuchal translucency measurement is feasible. Until further studies are done, however, risk assessment in multiple gestations should be performed judiciously, and patients who are at increased risk of aneuploidy should be counseled regarding diagnostic testing.

It all boils down to if knowing makes a difference.  For me, I was only concerned about Trisomy 21 because there is a higher risk of cardiac anomalies, and I would want pedi cards readily available at delivery.  For Trisomy 13/18, I'd want to know in order to be prepared for a child who would not likely live.  For a neural tube defect, there are emerging surgeries that can be done to correct them in utero.

I would have rathered risked a false positive test and need an amnio than risk not knowing.  Everyone is different!!   

This was exactly why we changed our minds and elected to have the quad screen.

Wow - thanks for the additional info E&RMommy.  After my quad screen and further into my pregnancy I was on this board more and kept seeing all these posts about not getting the test because it's not reliable for multiples, etc. and I was so pissed my doctor never mentioned that.  But what you included above makes much more sense- it's just not as sensitive.  I think that's a better way to describe it, seeing as it's just a statistic to begin with.  You just made me feel so much better about a decision that I made MONTHS ago that still bothers me!