What are the facts about false negative pregnancy tests?
When done properly,
at-home pregnancy tests today can be highly accurate. There are, though few,
circumstances when they can give false findings.
While other factors can
skew a test's results, user error is typically the cause of false pregnancy
tests. Continue reading to find out what can result in a false negative
pregnancy test and how these tests function.
Ø What is a pregnacy test?
To find out if a person
is pregnant or not, a pregnancy test is used. An at-home pregnancy test is a
urine examination that assesses the body's concentration of the pregnancy
hormone human chorionic gonadotropin (hCG). Only during pregnancy does this
hormone become made, and it starts to show up right after the embryo attaches.
You can either insert the
test strip into your urine stream or dip it into a cup of collected pee to do
an at-home pregnancy test. If hCG is present, the test's antibody detects it
and latches onto it when the urine is applied to the device. When the hormone
is recognised, a colouring agent in the test is triggered, which causes a line
to appear or another sign of the pregnancy test results, such as a computerised
screen displaying "yes" or "no," to appear.
Ø How reliable are home pregnancy tests ?
According to Thomas M.
Price, M.D., medical director of the Duke Fertility Center and professor of
obstetrics and gynaecology, the at-home pregnancy tests now on the market are
"quite good assays."
According to Dr Price,
"the over-the-counter tests have gotten highly sensitive." "If
done properly, the false negative rate is less than 1%."
He says it's extremely
improbable that an at-home pregnancy test will give false positive results if
someone waits until the right period in their menstrual cycle and makes sure
that their pee is sufficiently concentrated before testing.
A pregnancy test could,
however, provide a false negative. Although Dr Price acknowledges that they are
"extremely unusual," false positive results are sometimes
conceivable.
Ø What
Might Lead to a Pregnancy Test That Is Falsely Negative?
·
Tests Done Too Soon
According to Dr Price,
timing is "nearly invariably" the reason for false negative pregnancy
tests, which means the user tested too soon.
The placenta may not have
created enough hCG for the test to detect it if someone takes the test too
early in their cycle. This might also happen if a person takes a pregnancy test
too soon after having sex. As soon as your period is missed, it is advised that
you test.
·
Condensed urine
If the urine being tested
is too diluted, that is another factor that could result in a false pregnancy
test. The amount of hCG in the urine may not be sufficient for the test to
detect if it is not concentrated enough. There are a few possible reasons why a
pregnancy test would come back negative.
Dr Price advises against
drinking anything for a couple of hours before taking a pregnancy test because
of this. Due to the likelihood that you didn't drink anything overnight, urine
also tends to be less diluted first thing in the morning.
·
Fragmented or excessive HCG hormone levels
False pregnancy test
results can also happen if the hCG hormone is present in excess or if the test
detects the hormone's degraded form, known as the hCG core fragment, which
tends to rise as a pregnancy advances.
In the first case, when
there is too much hCG present, the test may be effectively overwhelmed by the
excessive levels of the hormone, leading to a false negative result. The
"hook effect" refers to this. Generally, the hook effect tends to
happen further along in pregnancy, when levels of hCG increase.
The second scenario takes
place when there is more of the hormone fragment present, which, once more, is
often when the pregnancy has advanced. In this situation, the test might detect
the broken-down hormone instead of the whole hormone. The fragmented hormone
does not activate the test's colouring agent because the signal antibody does
not react to it, producing a false negative.
Ø What
Happens if Pregnancy Tests Are Negative and My Period Is Late?
You're not alone if your
period is late but pregnancy tests keep coming back negative; according to Dr
Price, this occurs regularly because there are several causes for late periods
that are unrelated to a prospective pregnancy.
According to him, not all
women ovulate on a precisely regular schedule. And if you don't ovulate, your
period will either not come at all or come late.
However, if irregular
periods become commonplace, this may indicate a deeper problem. Several medical
conditions can be the reason women have irregular periods regularly, according
to Dr Price.
This may encompass
problems like thyroid issues and polycystic ovary syndrome (PCOS). In addition
to medical conditions, stress, intense exercise, and low body weight are other
variables that might result in missed periods.
Ø When
to Contact a Physician?
Dr Price advises calling
the doctor if a patient is worried or exhibits pregnancy-related symptoms but
receives inconsistent or negative test results. This is also true if a person
has trouble reading their test findings and is unsure whether they are positive
or negative.
Dr Price asserts that scheduling
a blood test is simple and that the results are "as accurate as you can
get."
Additionally, Dr Price
suggests visiting a gynaecologist if you have persistently irregular periods.