By Tassia O'Callaghan
Feb 28, 2024
•
6 min read
NM
Reviewed by Navya Muralidhar,
Embryologist
Whether you’re TTC or trying not to, having some home pregnancy tests stashed away for when you need them can be a good idea.So if your period hasn’t arrived, and you want to know if that old test in your bathroom is worth using.But do pregnancy tests expire?Or do they continue to give accurate results indefinitely?And if they do, how long do they last?Short answer? Pregnancy tests don’t last forever.Here’s how to use them to get the info you need so you can figure out your next steps.In this article: 📝
How do pregnancy tests work?
At-home pregnancy tests (and pregnancy tests at hospital) work by detecting hCG (aka “human chorionic gonadotropin”, AKA“the pregnancy hormone”).This hormone is released once an embryo implants in your uterus.As embryologist Navya Muralidhar explains, “the levels of hCG double every 48 hours after implantation”.If there are sufficient levels in your system, you’ll get a positive result on your pregnancy test.Pregnancy tests contain hCG antibodies, which react with the hCG in a pregnant person’s urine.This reaction produces an enzyme that triggers a positive result in the form of a colored line, “YES,” or a plus sign (+).Chemistry in your very own bathroom!But after a certain amount of time, those antibodies won’t be active anymore, so that reaction can no longer take place.And that’s why pregnancy tests have an expiration date.
When do pregnancy tests expire?
It depends on the manufacturer, but generally speaking, pregnancy tests can last about 2-3 years from their manufacturing date.But not all pregnancy tests are created equal — some of the cheaper ones could expire a bit earlier.The pricier pregnancy tests might age a bit more gracefully, with some holding onto their accuracy past their expiration date.Meanwhile, those budget-friendly options might start acting a bit wonky after a while, giving you false positives or negatives, leading to unnecessary stress and anxiety.So it’s worth shelling out a bit more for the expensive tests, or a new one from the pharmacy.Stick to the premium brands, and your whole pregnancy test experience will be smoother, more reliable, and a lot less confusing.And always check the expiry date on the packaging — it’s 2-3 years after their manufacturing date, not the date you buy them — they could have been on the shelf for a while.
Do expired pregnancy tests still work?
Maybe. But they’re not reliable.And that goes for both digital and non-digital options.The test’s expiration date is usually stamped on the box and often on the individual wrapping of each test.
How accurate are expired pregnancy tests?
The more sensitive tests (i.e. those that can detect smaller amounts of hCG) may last a little longer than others.But to be 100% sure, it’s best to stick within the expiration date.And that’s usually one to three years from when the test was manufactured.
Will an expired pregnancy test give a false negative?
There is a chance of getting a false negative with an expired pregnancy test, yes.There’s no way to know for sure if the hCG antibodies inside are still responsive.And if they’re not, you’ll get a negative result — even if there is hCG in your urine.So again, sticking with sticks still within their expiry date is best.
Can an old pregnancy test turn positive?
You’re more likely to get a false negative than a false positive on an old test.And that’s because the older they get, the less likely they are to pick up hCG in your system.But there is a chance that an older test could trick you into seeing a line that shouldn’t be there.Manufacturer’s instructions always say you should read a result within a certain time frame to avoid inaccuracies.After that period, if you see a line that wasn’t there before, it could be what’s commonly called an evaporation line.This is when the urine dries and leaves a faint colorless line behind.Frustrating and confusing — so it’s best to do what you can to follow the instructions exactly.If you’re hoping for a pregnancy, it can be so hard looking for that second line, month after month.A negative result may tempt you to go back and pull the test out of the trash to check.But it’s simply not worth it.Rather wait a couple more days and retest if your period still hasn’t arrived.
Best pregnancy test practice
Here’s our guide to help you make sure you get as accurate a result as possible.
- Check the date when you buy it.
- Check the expiration date when you use it.
- Store it in a cool dry place. Moisture or high humidity may also impact the accuracy of your result, especially if the test has been sitting in your medicine cabinet for quite some time.
- Test only after your period is due. This is a tough one, we know. Many tests claim to be able to give you a positive result days before your period is due. But they are in fact their most accurate a day or so after your missed period.
- Use your morning pee. Right when you first wake up — that’s when the hCG concentration is highest.
- Don’t be tempted to look at it again after the allotted time frame. It could cause you unnecessary confusion and heartache.
If you get a negative result, wait four or five days and try again if your period still hasn’t come.If you see a (colored) line within the time frame, no matter how faint, that’s a positive.Make an appointment with a healthcare provider to confirm the pregnancy as soon as you can.
Taking an expired pregnancy test may feel tempting.But we reckon it’s better not to even chance it.If you need to take a test and the ones you have are out of date, wait until you can get one you know you can trust.And if you’re unsure about when to take a pregnancy test, read more here.Whatever the result, your Peanut Community is here if you need to talk, rage, celebrate, cry, unload, or debrief. ❤️
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