Are Expired Pregnancy Tests Accurate? This Is What You Should Know.
Woman looking at an expired pregnancy test

What You Should Know About Using an Expired Pregnancy Test

Published September 14, 2017

Have you been nauseous these past few days, late on your period, and worried that you might be pregnant?

Do you have a few leftover pregnancy tests in the cupboard and wondering if you can use them even though they’re expired?

Home pregnancy tests are simple, easy to use, and give you results within minutes. Plus, they give you the ability to test within the seclusiveness of your own home and allow you to make changes to your lifestyle and find prenatal care as soon as possible if you are indeed pregnant.

But, is using an expired test just as accurate as using an un-expired test?

Do home pregnancy tests even truly expire?

In this post, we will discuss how home pregnancy tests work, when you should take one, if and when home pregnancy tests truly expire, and what you can expect when using an expired test.

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How Do Home Pregnancy Tests Work?

Early in pregnancy, a hormone called human chorionic gonadotropin (hCG) increases rapidly day by day. This hormone helps form the placenta and supports the development of your growing baby.

The test strip in a home pregnancy test contains a chemical that can detect the hCG in your urine, confirming or not if you are pregnant.

When Should I Take a Home Pregnancy Test?

Most doctors recommend waiting until one week after a missed period to take a home pregnancy test. However, there are some women who don’t experience a missed period or mistake implantation bleeding for a period.

If you absolutely cannot wait until you’ve missed your period, the earliest you should take a home pregnancy test is 14 days from the time you think you may have conceived.

You may be experiencing other symptoms of pregnancy during this waiting period, such as:

  • Nausea/vomiting

  • Lightheadedness

  • Fatigue

  • Tender, swollen breasts

  • Mood swings

  • Constipation

  • Food aversions or cravings

  • Slight bleeding and/or cramping

Do Home Pregnancy Tests Expire?

Did You Know?

Many women never even consider the fact that pregnancy tests expire and don’t ever look for an expiration date, but home pregnancy tests do in fact expire. All home pregnancy tests have an expiration date listed on the box or the outside packaging of the test.

The expiration date is set at the chemical’s expected shelf life. Once a test is expired, the test is essentially no longer valid, as the chemical will be ineffective at detecting the hCG hormone in your urine (source).

When Do They Expire?

The time frame on which a home pregnancy test expires varies, but most typically last between 2 to 3 years from the time they’re produced. The less expensive tests usually expire sooner, and the more pricey ones typically have a longer shelf life.

It is possible for expensive tests to be viable well beyond their expiration date. On the other hand, it’s also possible for cheap tests to no longer work months before the expiration date, as it might contain low quality chemical reagents. This is why it’s recommended to purchase tests that are at least 6 months away from when they expire (source).

Are Expired Tests Accurate?

Most home pregnancy tests claim to be 97 to 99% accurate when used correctly and taken one week after a missed period (source). But does this accuracy hold up when using an expired test?

It is possible for a home pregnancy test to be viable after its expiration date. However, most of the time they are more likely to give you false results.

Remember

Expired pregnancy tests are less likely to be able to detect the pregnancy hormone, as the chemical reactant has degraded, leaving you with a negative result, even if you truly are pregnant. This is called a false-negative result.

Although rare, it’s also possible to get a false-positive result with an expired pregnancy test, especially if the test has been exposed to heat or moisture. A false-positive is when you get a positive result, but you’re not actually pregnant.

Other Reasons Why You May Get a False Result

There are several other reasons besides the expiration date why you may be experiencing a false result on a home pregnancy test.

False Negative

  1. Taking the test too early: You may not have had enough hCG in your urine yet if you took the test too early. For best results, it’s advised to wait one week after your missed period to take a home pregnancy test.

  2. User error: Checking the results too soon, misinterpreting the results, and not using your midstream urine are all user errors that could potentially lead to a false negative result.

  3. Urine too diluted: The more dilute your urine is, the lower the concentration of hCG will be. This is why it’s recommended to use more concentrated urine (i.e., your first morning urine).

If you think you might be pregnant even with a false result, wait 5-7 days and retake the test. It may also be a good idea to go out and buy a new pregnancy test that is well before its expiration date.

False Positive

  1. Ectopic pregnancy: An ectopic pregnancy is where the fertilized egg implants somewhere other than the uterus, such as the fallopian tubes. An ectopic pregnancy is not a viable pregnancy, and can be dangerous, even fatal, if not treated. If you are experiencing severe abdominal pain or heavy bleeding, be sure to get in to see your doctor as soon as possible.

  2. Miscarriage: It can take weeks for the hCG hormone levels to drop back down after a miscarriage. If you had an early miscarriage, the hCG in your urine could be giving you a false positive reading.

  3. Fertility drugs: If you took the test too soon after taking a fertility drug with hCG, you could be experiencing a false positive result.

  4. User error: Reading the test too soon or too late could give you invalid results. Evaporation lines can also be mistaken for a positive test line. To avoid any misinterpretations, always be sure to carefully read the manufacturer's instructions before using a home pregnancy test.

If you think you may be getting false results or are getting mixed results, it may be a good idea to check in with your doctor and get a blood test to confirm conception. (source)

Anytime you get a positive result on a home pregnancy test; you should call and schedule your first prenatal appointment and start adjusting your lifestyle to accommodate your growing baby. That positive result could be a false-positive, but it’s more likely that you truly are pregnant.

What Should I Expect When Using an Expired Test?

What happens when you take an expired pregnancy test depends on the quality of the test itself, how much the chemical reactant has degraded, and if you are pregnant or not. You simply cannot rely on an expired home pregnancy test for accurate results.

If you chose to use an expired pregnancy test, be prepared for possible false results. Don’t jump to conclusions, as your results may or may not be accurate. If you do use an expired test, it’s best to go out and buy a new one (that is 6 months before it’s expiry date), to double check your results (source).

In Summary

Home pregnancy tests can give you fast, reliable results. But, to avoid any unnecessary doubts or false results, it’s always best to use a home pregnancy test that is well before it’s expiration date.

Most home pregnancy tests typically last 2-3 years from the time they were produced. Around the time of the expected expiration date, the chemical reactant in the test strip will start to degrade and lose its ability to detect the hCG hormone, leaving you with possible false results and worries.

Have you ever used an expired pregnancy test? Were the results accurate? Share your experiences with us in the comments below and be sure to share this post with all of your friends that are trying to conceive.

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Jenny Silverstone
 

Jenny is just another Mom trying to do her Best. She loves organizing things into lists and helping others find what they are looking for. When she's not using her powers to find her kids missing socks, you can find her giving actionable parenting advice & buyers guides at MomLovesBest.com

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