Why do home pregnancy tests expire?
Pregnancy tests, as was previously mentioned, contain a chemical that can identify hCG levels in urine. This substance, known as an hCG antibody, has two arms that can recognize and bind to hCG in urine. But after a while, the antibody arms degrade and lose their effectiveness. This is the most frequent explanation for a pregnancy test’s expiration date.
What happens if you take an expired pregnancy test
Over time, urine tests lose their ability to detect pregnancy entirely because they become less sensitive. This means that if you use a pregnancy test that is past its expiration date, the result will probably be wrong.
Most likely, youll get a false negative, which is when your test says youre not pregnant but you are. While less common, you can also receive a false positive, when the test says youre pregnant but youre not.
According to Blumenthal, if you’re more than a few weeks along in your pregnancy and your hCG levels are extremely high, you might still be able to get an accurate result from an expired pregnancy test.
But he adds that it’s best to avoid taking a chance and to only use pregnancy tests that are still valid. “Avoid using expired tests if at all possible,” Blumenthal says.
Check the expiration date on the pregnancy test box or get tested at your doctor’s office if you are experiencing early pregnancy symptoms like nausea, vomiting, or breast tenderness but your test is negative.
The effectiveness of pregnancy tests depends on whether the hormone human chorionic gonadotropin (hCG) is present in your pee. HCG is produced as soon as a fertilized egg attaches to the uterine wall and is a reliable sign of pregnancy. However, the chemical used in the test is delicate and may lose potency over time, according to Greves. (Companies don’t advertise the particular chemical they use, unfortunately. ).
Check the label on the pregnancy test you intend to purchase to ensure that it hasn’t gone bad. Beyond that, what you want to achieve ultimately determines the best test for you. Greves advises choosing a pregnancy test that specifically states that it can detect pregnancy before a missed period. (She claims that although they are typically more expensive, they also tend to be more sensitive.) Because digital pregnancy tests are made to detect lower levels of HCG in the blood than non-digital pee sticks, they typically provide more accurate early readings.
If you already missed your period, a generic test or one from your neighborhood dollar store might be sufficient as long as it hasn’t expired, according to Greves. Without a doubt, she advises, “just make sure the box and inside component isn’t opened—that can disturb the chemical and give you a false reading.”
However, there are numerous options available when you visit that area of your neighborhood pharmacy, making it difficult to know what to look for. The expiration date is one thing in particular you should pay close attention to. (With Women’s Health’s 12-Week Total-Body Transformation, get started on your new, healthy routine!)
Yup, pregnancy tests can actually expire. They typically last two to three years, according to Christine Greves, M D. , a board-certified ob-gyn at the Winnie Palmer Hospital for Women and Babies, and it might not provide accurate results if you use one after the expiration date stamped on the package.