Home Pregnancy Tests: How Accurate Are They?

Woman Checking Pregnancy Test Kit
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In today's society, when we want something, we want it now—and with at home pregnancy tests, that outlook is certainly no different.

You see ads for pregnancy tests everywhere. Each advertisement claims to be easier, faster and more accurate than the next pregnancy test. But how do you really know if those claims about accuracy are true and how do you sort through all of the information that comes with each test kit?

Pregnancy Tests: Starting with the Basics

There are two basic types of pregnancy tests. Blood pregnancy tests and urine pregnancy tests. They are both used to test for the presence of Human Chorionic Gonadotropic (hCG) hormone. Often referred to as the pregnancy hormone, hCG is secreted in your urine and detected in your blood beginning at different times during pregnancy.

Blood tests are conducted by a lab and are the more accurate of the two types of testing. Blood tests cannot only tell you if hCG is present, but a quantitative hCG can tell you how much hCG is present. This can be helpful in dating a pregnancy, or watching the levels to observe the well-being of the pregnancy. (hCG usually doubles about every two days during the first few weeks of pregnancy).

Urine tests are accurate for that they detect the presence of hCG. However, the amounts of hCG detectable by home pregnancy tests versus lab urine pregnancy test varies.

But How Accurate Are the Take Home Testing Kits Really?

The most sensitive test that I have found measures about 25 mIU/ml of hCG in the urine. While this information is not printed on the box, you can always call the toll-free advice line on the back of the box to inquire.

Most home pregnancy test kits claim that they are 97% to 99% accurate, though research has found that number to be much lower if the test is not used properly.

Factors that can affect the accuracy of the test include:

  • Using it beyond its expiration date
  • Exposure to sunlight
  • Not reading the instructions thoroughly before starting the test or following them exactly

In general, at home kits are accurate enough if you follow the instructions to a tee. This means reading all of the instructions before you start the testing.

If you choose to use an at-home pregnancy test (the urine type), you should use the following advice to help make the test more accurate:

  • If you are not using first morning urine, make sure that your urine has been in your bladder for four hours.
  • Do not drink excessive amounts of fluid in an attempt to increase the volume of urine, this can dilute the urine, making hCG not as detectable.
  • If you are taking any medications, including fertility drugs, read the package inserts before testing to see if your medications will affect the results of your home pregnancy test.

If your pregnancy test is positive make sure that you seek prenatal care from a qualified doctor or midwife.

Since false positives are pretty rare for women who are not on fertility medication, there's usually no need to retest after seeing a positive result on the pregnancy test.

If your result comes back negative, yet you still haven't gotten your period after your cycle's normal start date, you should retest—since not all pregnancy tests are sensitive enough to detect the low hCG levels that are present early on in pregnancy. 

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