How accurate is non-invasive prenatal testing?
Non-invasive prenatal testing (NIPT) is very good at detecting changes in the number of expected chromosomes in a fetus. The test is best when detecting changes in chromosomes 21 and 18. In this video, Patricia Geraghty, NP explains more about NIPT.
Transcript
[MUSIC PLAYING] When we talk about the accuracy of non-invasive prenatal testing, or NIPT, we're really looking at two different
numbers.
One number is the sensitivity or the detection rate. And what that tells us is, how good is
that this test at finding something that actually is there? Now, with NIPT, we're looking for changes in chromosomes
in the growing fetus. How good is the test at saying, yes, in fact, there's 2 21 chromosomes here or 3 18's or 3 13's.
So that's detection rate or sensitivity. NIPT appears to be very good at that, best at 21,
almost as good at finding 18's. Not as good up in the 80 percentile at finding 13's.
But a very important part of accuracy is also how good is the test at when it tells us there's something wrong, it's actually correct.
And we call that a false positive. It says that the fetus is affected, when in fact the fetus is not.
And with NIPT, over the existing genetic screening, what we really see is an improvement in that false positive rate
in other screening tests, with a very, very low false positive rate varying, again, with the different chromosomes from about 1 in 500 with 21
pregnancy
Browse videos by topic categories
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
ALL