False Negative Pregnancy Test

Home pregnancy tests are a woman’s best friend. They bear the first witness to a woman’s pregnancy. Most of the times these tests are accurate but have you ever considered a possibility of a false pregnancy test? Like a false negative pregnancy test or a false positive?  

You might be wondering: Can you get a false-negative pregnancy test? Unfortunately but such results are quite common.

In this article, we will try to understand what is a false negative pregnancy test, how common are false negative tests and their causes.

What is a false negative pregnancy test?

A false negative pregnancy test is when the pregnancy test shows that you’re not pregnant albeit you are pregnant.

False-negative pregnancy after a missed period is a major concern of mothers to be. 

False negative pregnancy test
False negative pregnancy test

What can cause a false negative pregnancy test?

Listed below are some of the false negative pregnancy test causes:

  1. Low hCG production: Your body might be producing a minute amount hCG, and the doubling on hCG would take more than 48 hours. So in such a situation, you will get a false negative PT. Home pregnancy tests are unable to low levels of hCG thus giving a false-negative result.
  2. Not following the pregnancy test instructions: One must read the instructions insert in the pregnancy test box. Every pregnancy test is different, and hence you have to be particular about the steps. If you don’t follow them, then you are likely to get a false negative PT.
  3. Using a diluted urine sample: At the time you take a home pregnancy test your pregnancy is at an early stage. Hence your body doesn’t have enough hCG. For this reason, the pregnancy test should be conducted early morning. This way your urine gets concentrated overnight and hCG accumulates in it. If you don’t use a concentrated urine sample, then your urine will have less hCG per unit volume of urine. In every drop, the amount of hCG sticking to the hCG strip will be less increasing the probability of a false negative PT.
  4. Taking the pregnancy test too early: If you take the pregnancy test before implantation has occurred then your body won’t have enough hCG. Again, in this case, the amount of hCG will be so low that it won’t be detectable by the pregnancy test. It is critical to know how soon you can take the pregnancy test and when to take the pregnancy test.
  5. Tubal pregnancy or chemical pregnancy: Tubal pregnancy and chemical pregnancy are the different names for a pregnancy that doesn’t have a normal course. Ectopic pregnancy is when embryo implants in the uterus. Ectopic pregnancy causes a false negative result. There is no way to sustain a tubal pregnancy, and the only fate they have is abortion or miscarriage. Such conditions give wrong results because if the embryo doesn’t get implanted, then no hCG or very scanty hCG is produced.
  6. Taking the test after a missed period: Taking a pregnancy test immediately after missed periods will also give a false-negative PT. This is because it is too early to take the pregnancy test.
  7. Reading the test results after allotted time: Reading the results after the allotted time will again give you a false negative result. This is because the results will disappear after the reading time has passed.
  8. Disregarding a faint positive pregnancy test as an evaporation line: If you are not vigilant of faint positive pregnancy test and take it to be an evaporation line, then you will get a false negative pregnancy test. It is important to know that no matter how faint a positive pregnancy test line it shows that you are pregnant.
  9. Using an expired pregnancy test: An expired pregnancy test will not be able to detect pregnancy. Hence it will mostly give an incorrect negative pregnancy test. It is because the hCG detector particles become non-functional once a pregnancy test expires. If the detector particles don’t work, then the pregnancy test won’t be able to give accurate results.
  10. Medical prescriptions: Certain medicines cause a false negative pregnancy test because they do not allow the hCG level to rise rapidly and hinder its production. Taking birth control can also be a reason for wrong results.

How common is false negative pregnancy test?

After knowing the reasons, you must be wondering How common are false negative pregnancy tests?’ A false negative pregnancy test is common pregnancy test error. 

It is more likely that one gets a false negative than getting a false positive pregnancy test.

False negative pregnancy test rate

Chances of false negative pregnancy test increase if you do not follow pregnancy test instructions. There are no official figures for this, but many women fall prey to it.

Any woman taking a urine pregnancy test for the first time can get a false-negative pregnancy test.

False negative pregnancy rate varies according to the brand. If you use a good quality pregnancy test chances are less that you will get wrong results.

Drinking caffeine before the pregnancy test can cause a false-negative pregnancy test. Certain medicines also trigger wrong results.

False negative pregnancy test after IUI

Intrauterine insemination is the infertility treatment in which doctors put seminal fluid directly inside a woman’s vagina.

hCG fertility drugs injected in the last phase of IUI treatment elevate hCG levels for 10-12 days.

During this time a woman must not take the home pregnancy test after IVF because it gives a false positive pregnancy test.

Once hCG (due to fertility drugs) leaves your body, then you start getting a negative pregnancy test.

This is a false-negative pregnancy test after IUI. Later you will get pregnant, but it takes some time.

What is best to do after false negative pregnancy test?

If you get a false-negative pregnancy test, but you see the symptoms of early pregnancy in you, it is best that you see your doctor now. She will perform a blood test and test your pregnancy accurately. See our detailed guide on what to do after a false negative pregnancy test?.



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