Genetic Testing and Pregnancy

(music.) Down syndrome affects one in
every seven hundred babies born each year in
the United States and now thanks to
advanced breakthroughs there’s a
non-invasive screening option called NIPT,
here to talk about this fairly new
approach to prenatal testing from Alumina is
genetic counselor Patty Winters. Thank
you for being here Patty. Thank you. Okay, so before we even get into
what NIPT is. Tell us a
little bit about the difference between
a screening test and a diagnostic test. A
screening test is a test that can tell
us if there’s a higher or a lower chance
for certain medical conditions in a
pregnancy, whereas the diagnostic tests
usually a CVS or amniocentesis during
pregnancy actually samples from the
pregnancy and can tell us yes or no with
as much certainty as possible whether
those conditions are present. NIPT is a
type of screening test where we actually
draw blood from a woman’s arm and in her
blood there is some cell free DNA from
both herself and from the pregnancy and
by analyzing that cell free DNA we’re
able to determine if there’s a higher or
lower chance for certain conditions in
the pregnancy. So some women
will choose to have a screening test to get
that information before deciding
whether to have a diagnostic test because
the diagnostic test carries a risk
of complications including
pregnancy loss. So what does NIPT screen for? It
screens for changes in the number of
certain chromosomes so most commonly we
talk about Down syndrome which is
trisomy 21 which is an extra copy of
chromosome 21 but NIPT also screams for
trisomy 18 which is also called Edwards
syndrome and trisomy 13 which is also
called Pito Syndrome and it also looks
at the sex chromosomes to see if
there’s any missing or extra sex
chromosomes. So Patty, I shared with you
before, my husband and I are trying to have a baby. And
at this point in my life, I’m considered at advanced maternal
age. So is
this test specifically for women of
advanced maternal age or are there other
candidates? So we know that
these conditions can occur in any pregnancy. So
there’s a change for these with every pregnancy that any
woman has but as you mentioned, there are pregnacy’s that have a
higher chance for these conditions. based on things
like, how old a mom is or her pregnacy history or her
family history but because these conditions can
occur in any pregnancy, The American College of
Obstetricians and Gynecologists actually
recommends that all women during pregnancy be
offered screening and diagnostic testing
options for these chromosome conditions. So Patty
what are some of the advantages of NIPT
and in terms of the technology how
accurate is it? NIPT is actually
an improvement on some of the older
serum screening options so
historically serum screening options had a false
positive rate which means the woman gets
her blood drawn and gets a positive
result but the pregnancy is actually
not affected and that happened in
about 1 in 20 women with NIPT the false
positive rate for Down syndrome is closer
to 1 in 1,000 so we’re greatly reducing
the number of women who are
receiving these false positive results which
means that fewer women are being offered
diagnostic testing and are avoiding the
complications associated with those
procedures such as potential miscarriage. So for women who are thinking
about having an NIPT is there anything
else you need to know before we do this? I think
it’s important for women to understand
that these tests are optional so that
it’s volunteer it’s your decision if you
want to have any of these screening or
diagnostic tests during pregnancy,
secondly it’s important to remember that
we’re only screening for certain conditions so we’re not looking
for all genetic conditions and we’re not
looking for all birth defects which
means that a negative result is very
reassuring but it won’t tell us for sure that
the pregnancy is developing healthy,
and then finally it’s important to
remember that there’s different laboratories
that offer NIPT and that these might
differ so you need to find out what is
your specific test going to tell you
how does that specific test perform and
what is the chance that you won’t get a
result or that you’ll have a failed
test through that laboratory so it’s
really important to have a conversation
with your doctor make sure that you
choose the test that’s going to give
you fast and reliable results most often. Yes a
little peace of mind what a future
parent doesn’t want a little bit of that. Thank you so much for being here
Patty. Thank you. And if you want more
information about non-invasive prenatal
testing you can go to Alumina dot com, ask
your doctor, or of course you can always
visit our website
for more. (music.)

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