nuchal fold test necessary?

My wife is pregnant (nearly 8 weeks now).

Pregnancy books discuss the nuchal fold test.

It seems like it's mainly for predicting Downs and other genetic disorders.

Since we've made the decision that we won't abort for genetic disorders, is
there any reason to have this test? (We can't think of any.)

TIA

newly_pregnant wrote:
My wife is pregnant (nearly 8 weeks now).

Pregnancy books discuss the nuchal fold test.

It seems like it's mainly for predicting Downs and other genetic disorders.

Since we've made the decision that we won't abort for genetic disorders, is
there any reason to have this test? (We can't think of any.)

It is a screening test for Downs Syndrome, which means
that it doesn't diagnose DS. It simply identifies whether
you are at higher risk and might therefore benefit from more
extensive testing to get a definitive diagnosis. Therefore,
it is not a useful test if A) you would refuse further testing
(e.g., amnio) or B) if knowledge of a diagnosis of DS (or
knowledge of increased risk of DS) would not change your
decision making. Obviously, pregnancy termination is the
biggest decision one would confront. Some people might
want the information in order to make other decisions (making
preparations, change birth location, etc.). However, if
you would not terminate, the other decisions you would make
would generally be for your personal comfort level. E.g.,
some people would be reasonable comfortable finding out
about a diagnosis at birth and dealing with whatever issues
at that moment. Some other people would be eaten alive with
worry and doubt without knowing and would want a definitive
diagnosis ahead of time so they could study and plan and
whatever. So, some people choose to find out even if they
don't plan to terminate. (However, statistics suggest that
a significant majority who find out *do* terminate.)
So, bottom line is that some may make an argument
for why you might want to know even if you wouldn't
terminate, but it's certainly not essential to get a
diagnosis.

Best wishes,
Ericka

"Necessary?" No. Very few things are really "necessary."
Desirable? Useful? Very possibly - even if you know you would not
terminate.

Nuchal fold and nuchal lucency are two different tests. If you are
talking about a test in early pregnancy, you are talking about the
nuchal lucency test. Ideally this should also be combined with a blood
test.

Some possible uses of prenatal screening for people who believe they
would not terminate for fetal anomalies:

1) reassurance - if you are worried about the possibility of karotypic
anomalies, the combined nuchal lucency + blood test is extremely
reliable. If you get a negative result, you can be confident the baby
does not have Down syndrome.

2) perinatal hospice - Down syndrome is not the only karotypic
anomaly. If the baby has a lethal fetal anomaly (a condition
incompatible with life outside the womb), some families prefer to plan
a perinatal hospice. Without a diagnosis prior to birth, a baby with a
lethal anomaly will probably wind up spending his or her entire life
being resuscitated by a team of strangers. When families know about a
lethal anomaly prior to birth, they can call off the resuscitation
efforts and plan for peaceful family time instead. If I were a baby
with a lethal fetal anomaly, I would much prefer to spend my 20
minutes or 6 hours of life in my parents' arms.

3) planning early neonatal care - babies with Down syndrome have a
much higher incidence of malformations involving the heart and the
airway. If your baby had one of these conditions, foreknowledge of the
condition would enable potentially life-saving treatment in the
delivery room.

The idea that prenatal diagnosis is a "search and destroy" method with
no purpose other than to terminate anomalous babies is a myth. One of
the leading prenatal diagnosis physicians in the US is also the
president of the association of pro life ob gyns.

"alath" wrote in message
ups.com...
"Necessary?" No. Very few things are really "necessary."
Desirable? Useful? Very possibly - even if you know you would not
terminate.

Nuchal fold and nuchal lucency are two different tests. If you are
talking about a test in early pregnancy, you are talking about the
nuchal lucency test. Ideally this should also be combined with a blood
test.

Some possible uses of prenatal screening for people who believe they
would not terminate for fetal anomalies:

1) reassurance - if you are worried about the possibility of karotypic
anomalies, the combined nuchal lucency + blood test is extremely
reliable. If you get a negative result, you can be confident the baby
does not have Down syndrome.

2) perinatal hospice - Down syndrome is not the only karotypic
anomaly. If the baby has a lethal fetal anomaly (a condition
incompatible with life outside the womb), some families prefer to plan
a perinatal hospice. Without a diagnosis prior to birth, a baby with a
lethal anomaly will probably wind up spending his or her entire life
being resuscitated by a team of strangers. When families know about a
lethal anomaly prior to birth, they can call off the resuscitation
efforts and plan for peaceful family time instead. If I were a baby
with a lethal fetal anomaly, I would much prefer to spend my 20
minutes or 6 hours of life in my parents' arms.

3) planning early neonatal care - babies with Down syndrome have a
much higher incidence of malformations involving the heart and the
airway. If your baby had one of these conditions, foreknowledge of the
condition would enable potentially life-saving treatment in the
delivery room.

The idea that prenatal diagnosis is a "search and destroy" method with
no purpose other than to terminate anomalous babies is a myth. One of
the leading prenatal diagnosis physicians in the US is also the
president of the association of pro life ob gyns.

Thanks for the very informative reply. (That goes for the other responding
poster, as well.)

You wrote, "If you get a negative result, you can be confident the baby does
not have Down syndrome." That's my impression from reading around (low
false negative rate).

However---and I should emphasize this is only an impression from some
initial skimming of material---isn't the false positive rate fairly high?
I.e., the probability that the baby does not have Downs, given that the test
is positive, is pretty high.

If so, that would lead us to not wanting to get the test in that the
cost/benefit payoff doesn't seem so great. (Meaning we can live with not
knowing, and the cost of the stress induced by a false positive would
outweigh the benefits of knowing in the case there really was Downs. Not to
denigrate your points made above, which are well-taken and informative.)

alath wrote:
"Necessary?" No. Very few things are really "necessary."
Desirable? Useful? Very possibly - even if you know you would not
terminate.

Nuchal fold and nuchal lucency are two different tests. If you are
talking about a test in early pregnancy, you are talking about the
nuchal lucency test. Ideally this should also be combined with a blood
test.

Some possible uses of prenatal screening for people who believe they
would not terminate for fetal anomalies:

I do agree with what you're saying in general, but want
to play devil's advocate a bit...

1) reassurance - if you are worried about the possibility of karotypic
anomalies, the combined nuchal lucency + blood test is extremely
reliable. If you get a negative result, you can be confident the baby
does not have Down syndrome.

However, this reassurance is not complete (prenatal
screening won't detect everything, and isn't 100 percent reliable
detecting the things it can detect) and comes at a price (if
you *don't* get a negative result, that affects your experience
of pregnancy as well. Some people have started looking at
the emotional and psychological consequences of prenatal testing,
and the results are mixed and a bit complicated (and sometimes
counter-intuitive). Does this mean that one shouldn't test?
Of course not. But it does mean that testing is not an unalloyed
good. I think it's worth considering some of the downsides as
well, beyond just the technical false negatives and false
positives.

2) perinatal hospice - Down syndrome is not the only karotypic
anomaly. If the baby has a lethal fetal anomaly (a condition
incompatible with life outside the womb), some families prefer to plan
a perinatal hospice. Without a diagnosis prior to birth, a baby with a
lethal anomaly will probably wind up spending his or her entire life
being resuscitated by a team of strangers. When families know about a
lethal anomaly prior to birth, they can call off the resuscitation
efforts and plan for peaceful family time instead. If I were a baby
with a lethal fetal anomaly, I would much prefer to spend my 20
minutes or 6 hours of life in my parents' arms.

Absolutely agreed. However, I'm not sure that this
particular issue hangs a lot on the nuchal lucency test. Some
of us nutters aside, most folks have a mid-trimester ultrasound
that probably catches more of this sort of thing than just
about anything else. That's not to say that the u/s associated
with the nuchal lucency wouldn't give an earlier heads up about
some of these issues, but just that refusing the nuchal lucency
doesn't deprive one of this opportunity. And, of course,
while some people want to plan based on a diagnosis, it is
also possible to put a plan in place just the same as many
perfectly healthy people have a "living will" to tell caregivers
what they want to happen in the event that something unexpected
happens.

3) planning early neonatal care - babies with Down syndrome have a
much higher incidence of malformations involving the heart and the
airway. If your baby had one of these conditions, foreknowledge of the
condition would enable potentially life-saving treatment in the
delivery room.

And also with this one, while a positive on the nuchal
lucency screen (or a diagnosis resulting from further testing)
would perhaps make one look more closely, it's probably more
the mid-trimester ultrasound that would detect these malformations
(associated with DS or not) that would form the basis for
making such plans, no?

The idea that prenatal diagnosis is a "search and destroy" method with
no purpose other than to terminate anomalous babies is a myth. One of
the leading prenatal diagnosis physicians in the US is also the
president of the association of pro life ob gyns.

Again, just to reiterate, I do absolutely agree
that prenatal diagnosis is not just about "search and destroy."
I do think, however, that it is worth considering exactly
what one would do with the information (including precisely
the things you describe above) and the potential alternate
sources of information (and their attendant risks and benefits)
in order to make a sensible decision for one's personal
situation. I also think that it is valid to consider one's
personal feelings and how testing and dealing with the
results of testing affects one's experience.

Best wishes,
Ericka

"Ericka Kammerer" wrote in message
. ..
snip

Again, just to reiterate, I do absolutely agree
that prenatal diagnosis is not just about "search and destroy."
I do think, however, that it is worth considering exactly
what one would do with the information (including precisely
the things you describe above) and the potential alternate
sources of information (and their attendant risks and benefits)
in order to make a sensible decision for one's personal
situation. I also think that it is valid to consider one's
personal feelings and how testing and dealing with the
results of testing affects one's experience.

Thanks for your added input.

Like I said in my reply to Alath's informative post, to me false positive
also represents a risk.

Best wishes,
Ericka

newly_pregnant wrote:


Since we've made the decision that we won't abort for genetic disorders, is
there any reason to have this test? (We can't think of any.)

The other posters who responded gave you great information.

I'm currently expecting #4 (5th pregnancy) and this is the first time
I've had any screening tests performed. One of my children has cerebral
palsy, and I mainly wanted to know whether we had an increased risk of
having another child with special needs, just to prepare mentally for
more years of specialists and therapy. We would not terminate either. My
risk came back very low, and we won't have any further testing (although
I'll be having amnio to check for lung maturity if I make it to 36 weeks).

In my previous pregnancies, I've declined all screening tests other than
the standard ultrasounds (of which I have a lot because my pregnancies
are quite high risk and followed closely by a maternal-fetal
specialist). Anyway, that was my reasoning for opting to have the tests
done this time.

Congratulations and best of luck!

Paula
20w2d w/ #4
Mom to Olivia & Cassie, born 4/8/03 @ 26 weeks
and Noah, born 6/1/05 @ 35 weeks

while some people want to plan based on a diagnosis, it is
also possible to put a plan in place just the same as many
perfectly healthy people have a "living will" to tell caregivers
what they want to happen in the event that something unexpected
happens.

"make it up on the fly" doesn't work very well for perinatal hospice.
You may only have 30 minutes or half a day. As long as the diagnosis
is uncertain (ie; not known whether or not it is lethal), the default
position is going to be aggressive treatment. In the case of a lethal
karotypic anomaly, the results will probably not be back until after
the baby passes away. For people who want to make the most of the very
limited time they may have with their newborns, having the diagnosis
ahead of time is critical.

would perhaps make one look more closely, it's probably more
the mid-trimester ultrasound that would detect these malformations
(associated with DS or not) that would form the basis for
making such plans, no?

Yes, it is possible that the midtrimester ultrasound may trigger
further studies and a diagnosis can be made then. However, the
findings we are talking about can be very subtle and difficult to
detect especially in the case of heart defects. As a practical matter,
for most patients, having an early abnormal nuchal lucency screen
could be the difference between having multiple specialized
ultrasounds in a perinatal diagnostic center, versus having a quick
"routine" scan in the doctor's office.

I have known of more than one case of a lethal chromosome abnormality
that was missed on "routine" office ultrasounds. One of these women
had an emergency cesarean section that could certainly have been
avoided if the lethal diagnosis had been known beforehand.

Again, just to reiterate, I do absolutely agree
that prenatal diagnosis is not just about "search and destroy."
I do think, however, that it is worth considering exactly
what one would do with the information (including precisely
the things you describe above) and the potential alternate
sources of information (and their attendant risks and benefits)
in order to make a sensible decision for one's personal
situation. I also think that it is valid to consider one's
personal feelings and how testing and dealing with the
results of testing affects one's experience.

Of course. I don't think anything I have said is contrary to any of
this. I didn't say "everyone should mindlessly get every possible
test, just because." The question was, "is there any way a nuchal
lucency test could be helpful for someone who is not going to
terminate?" I listed three ways it could potentially be helpful.

However---and I should emphasize this is only an impression from some
initial skimming of material---isn't the false positive rate fairly high?
I.e., the probability that the baby does not have Downs, given that the test
is positive, is pretty high.

The combined nuchal lucency and maternal blood test has sensitivity
and specificity both in the high 90's. False positives are quite rare
with this test. The vast majority of women who get these tests have
negative results and normal babies.

alath wrote:
while some people want to plan based on a diagnosis, it is
also possible to put a plan in place just the same as many
perfectly healthy people have a "living will" to tell caregivers
what they want to happen in the event that something unexpected
happens.

"make it up on the fly" doesn't work very well for perinatal hospice.
You may only have 30 minutes or half a day. As long as the diagnosis
is uncertain (ie; not known whether or not it is lethal), the default
position is going to be aggressive treatment. In the case of a lethal
karotypic anomaly, the results will probably not be back until after
the baby passes away. For people who want to make the most of the very
limited time they may have with their newborns, having the diagnosis
ahead of time is critical.

What is to prevent someone for filing the something
ahead of time, regardless of whether or not there is an
advance diagnosis, specifying under what conditions they
are interested in aggressive treatment? (I am not suggesting
this is something that most people do--many people don't even
do this for themselves, and then end up in difficult circumstances.
I'm just asking why this would be impossible.)

would perhaps make one look more closely, it's probably more
the mid-trimester ultrasound that would detect these malformations
(associated with DS or not) that would form the basis for
making such plans, no?

Yes, it is possible that the midtrimester ultrasound may trigger
further studies and a diagnosis can be made then. However, the
findings we are talking about can be very subtle and difficult to
detect especially in the case of heart defects. As a practical matter,
for most patients, having an early abnormal nuchal lucency screen
could be the difference between having multiple specialized
ultrasounds in a perinatal diagnostic center, versus having a quick
"routine" scan in the doctor's office.

Does this happen often? Because it seems to me that
nearly everyone I've known who's had *any* ultrasounds have
had a rather extensive mid-trimester u/s where they were sent
to a lab and examined for quite an extensive period of time.
I've known many who have *also* had lots of quickie u/s
in the doctor's office, but I can't think of anyone IRL who's
chosen to have u/s at all who hasn't had a substantive
one with the specific goal of checking everything out.

I have known of more than one case of a lethal chromosome abnormality
that was missed on "routine" office ultrasounds. One of these women
had an emergency cesarean section that could certainly have been
avoided if the lethal diagnosis had been known beforehand.

Still, I think we have to be very wary of this notion
that prenatal diagnosis guarantees perfect babies. I realize
that care providers do not make this claim; however, at some
level, that is what many people believe. You have the tests,
there are no findings, and the baby will be perfect. Prenatal
testing has fundamentally affected the experience of pregnancy,
and not entirely in a positive way. Yes, it provides useful
information that allows us to make important medical decisions
that lead to better outcomes. At the same time, there are
downsides as well. I'm trying to remember the name of a
book I read about a year ago that was a collection of papers,
some of which addressed this issue, but I guess it's just
going to have to keep nagging at me for a while because I
can't seem to dredge it up out of my memory or find it online
with the search terms I can think of! That's all a bit of
an aside, though.
Actually, the thing that made me comment about the
mid-trimester u/s was more that even if you had a diagnosis
of Downs syndrome (or a similar genetic anomaly), you still
wouldn't know for sure whether or not there would be, say,
cardiac problems. You'd know the risk was elevated, and
so maybe you'd look more closely, but you'd still have to
rely on u/s to make the decision about whether immediate
intervention was needed at birth. The detection of the
genetic anomaly in and of itself wouldn't give you the
information you needed. So, the question is, if you are
going to have a detailed mid-trimester anomaly scan anyway,
and you would not consider termination, but would like to
make some plans in case immediate intervention at birth
was needed, do you still *need* the nuchal lucency test?

Again, just to reiterate, I do absolutely agree
that prenatal diagnosis is not just about "search and destroy."
I do think, however, that it is worth considering exactly
what one would do with the information (including precisely
the things you describe above) and the potential alternate
sources of information (and their attendant risks and benefits)
in order to make a sensible decision for one's personal
situation. I also think that it is valid to consider one's
personal feelings and how testing and dealing with the
results of testing affects one's experience.

Of course. I don't think anything I have said is contrary to any of
this.

It's not that it's contrary. It's just that *all*
prenatal tests have some potential to generate actionable
information. If that wasn't the case, the test wouldn't
exist ;-) This leads very rapidly into the idea that
all tests are worthwhile, because there is *some* possibility
that they could provide information. As the limits of science
and medicine are expanded, this becomes even *more* complicated,
because we can do more things to fix what we might find.
It becomes very difficult to say no to tests, because there's
a sense that you owe it to your baby to give him or her *every*
*single* *chance* to identify a potential issue and fix it.
Nevertheless, every bit of information has a cost and unintended
consequences associated with it. Those costs and consequences
are very difficult to articulate, so they often don't get
considered. It isn't an easy balance to find.

I didn't say "everyone should mindlessly get every possible
test, just because." The question was, "is there any way a nuchal
lucency test could be helpful for someone who is not going to
terminate?" I listed three ways it could potentially be helpful.

Right, and I agree that those are things to consider.
I'm just once again making the argument that there's another
side to consider that shouldn't get lost in the equation, and
that people should not be afraid to weigh some of the "squishier"
factors in making their personal decisions.

Best wishes,
Ericka