What are the facts about false negative pregnancy tests?


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?

 Factors which lead to a pregnancy test that is falsely negative are ;

·       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.

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