Late period and nauseous? If you’re worried that you might have fallen pregnant, chances are you’ll be reaching for the nearest pregnancy test.
A home pregnancy test offers you a quick and effective method to check if you’re pregnant from the comfort of your own bathroom.
While you may have a couple tucked away in the cupboard, you might be asking yourself do pregnancy tests expire? Are expired pregnancy test as accurate as brand new ones?
In this post we find out how home tests work, when to take one, if and when they expire and what to expect when using and expired test.
How Do Home Pregnancy Tests Work?
During the early stages of pregnancy, your placenta makes a hormone called human chorionic gonadotropin (or hCG for short) which supports the development of your baby as he grows.
Home pregnancy work by detecting the presence of hCG in your urine to confirm whether or not your pregnant.
Taking A Home Pregnancy Test
The general consensus is that you should wait one week after a missed period before taking a home pregnancy test. However, it’s not always as straight forward as some women either don’t miss a period or confuse implantation bleeding for a period.
While it’s not as accurate, if you can’t wait for your missed period and think you’ve conceived then the earliest that you can take a test is around 14 days after the conception date.
There are a number of other symptoms that might lead you to thinking that you’re pregnant. These include:
- Sickness, nausea or vomiting.
- Tender, sqollen breasts
- Suddenly going off certain foods
- Food cravings
- Slight bleeding and cramping
Do Home Pregnancy Tests Expire?
Few women ever check the expiration date of a home pregnancy test as they never think that they can expire.
However, if you take a look at a packaging box, you’ll notice that they do in fact have an expiration date listed on the packaging.
The expiration date references shelf life of the tests hCG detecting chemicals. Once an expiration date passes, a test is no longer considered valid as the chemical won’t be as effective at detecting hCG so could provide a false reading.
When Do They Expire?
While the chemical expiration time does vary from test , typically even the best detection will start to become less accurate after two years. Be very careful if you opt for a cheap test as these can become inaccurate after only a year.
Broadly speaking, for the most accurate results, it’s always best to either buy a new test each time you want to check your pregnancy status or only keep tests for siz months before replacing them.
Are Expired Pregnancy Tests Accurate?
Most tests claim to be around 98% accurate when the test is taken one week after a missed period and used correctly, but does this still hold true for an expired test?
We personally always advise that a home pregnancy test isn’t used after an expiration date as it’s more likely to give a false reading than a recently purchased one.
The reason for this is that as the chemical used to detect hCG degrades, the ability to detect the hormone decreases, leading to false negative test results.
While it’s not as common, it’s entirely possible for expired tests to give a false positive reading, telling you that you’re pregnant when in fact the test is negative.
What Can You Expect When You Take An Expired Test?
The results of an expired test really depend on how expired the test is. While you might get a fairly accurate reading is the test is only a few days out of date, a test that’s months and months out of date is unlikely to give you a true reading.
Personally, I’d never put much faith in an expired test given how the accuracy suffers with them.
The Bottom Line
Home pregnancy tests can provide you with a fast and easy indication of whether you’re pregnant or not.
However, to make sure that you’re getting the very best reading, you want to use a test that’s under six months old to ensure that the chemicals used are as accurate as possible.
Ellen Fetters, is a former Children's and Young People's Nursing Practice with an BSc from the University of Sunderland. After completing her SCPHN - HV she then worked as a Health Visitor within the local community.
In 2017 Ellen left nursing to launch Parenting Click, an online parenting resource aimed at creating happier families through better parenting.
She lives with her husband, beautiful baby girl, and two darling dogs. She spends her free time writing, running and learning how to become a better parent.