Are Pregnancy Tests Accurate?

Are pregnancy tests accurate? It’s a great question that we had this week on our Facebook page, unfortunately, there is not a hard and fast answer. We know from research that on average women take 3 pregnancy tests when determining if they are pregnant and some women will continue to test even after a blood test at the doctor just to be sure it’s still there….

The majority of pregnancy tests sold in stores are 99% accurate, which means that 1 in 100 tests will be wrong in the information they give you, so there can be merit to taking more than one test….

What Affects Pregnancy Tests?

A pregnancy test result can be affected by numerous factors…

When You Take the Test
If you take the test too early your body may not have started to produce enough hCG hormone (human Chorionic Gonadotrophin) to show up on the test. The level of hCG in your body will double every 2-3 days, so best to wait and take a test again the next day. Also in the early days of pregnancy, you want to test on your first urine of the day, this is when your levels of HCG will be most concentrated.

Water Consumption
If you have been drinking lots of water the day before you take the test that can water down the hCG levels in your urine which means that the test doesn’t register you as pregnant. The solution? If you are planning to take a test make sure you don’t drink gallons more water than you usually do the day before.

How Sensitive the Test Is
Pregnancy tests can measure the hCG in your urine from levels as low as a sensitivity of 10mIU/ml, but others won’t measure a positive result until an hCG sensitivity of 25mIU/ml, so if you are testing super early say after an embryo implantation one day you may not be pregnant and the next you are.

Medications You are Taking
In rare instances, you can get a false positive from certain medications containing the hCG hormone, like some fertility treatments. Just check with your doctor about this, as it isn’t all fertility medications.

If You Have Been Pregnant and have Miscarried 
After you miscarry there will still be levels of hCG in your body, on a test it could show that you are still pregnant. The best way to get this 100% confirmed is through an internal ultrasound. This could be due to a chemical pregnancy which is when the loss occurs just after implantation. I think that this is what happened to me, and apparently, it happens to 1 in 4 women, most wouldn’t know unless they have done something like IVF or ovulation tracking and are actively testing early.

The Test Has Expired
Most pregnancy tests that you buy have an expiry of 2 years from manufacture, it will say on the box and the pouch that the test comes in when it expires. Unlike other things that you would use after the expiry date, seeing it as a guideline rather than a deadline, eg jam or paracetamol pregnancy tests genuinely can give you a dodgy result if you use it after the expiry date. The lesson here is don’t stockpile 100s of tests, just buy 1 or 2 as you need!

Ectopic Pregnancy
This is when the egg hasn’t been implanted in your uterus but in your fallopian tubes. This is very dangerous, as the embryo grows it can cause the tube to burst or damage surrounding organs, which can cause major internal bleeding and require immediate surgery. The chances of this happening are very slim – 1-2% of all pregnancies are ectopic. This article on Healthline goes into more detail about ectopic pregnancies and the signs.

Too Far Along
WIth pregnancy tests, it gets to the stage where your hCG levels are so high that the test can’t cope and will tell you that you aren’t pregnant even though you are. This usually happens at the end of the first trimester or in the second trimester when your hCG levels are so high that they oversaturate the test and produce a false negative.

The moral of the tale as to are pregnancy tests accurate is that it depends on a few factors, but the majority (99%) of the time they are, if you are unsure take a second test, and if you are still in disbelief or despair contact your doctor to get a blood test to measure your hCG levels. Good luck readers and lots of baby dust to you all.

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