Few things are as life altering as becoming pregnant. When a woman thinks that she may be pregnant, the worst part is having to wait to find out for sure. Today, there’s an entire industry built around pregnancy tests. These tests differ in how they work, as well as in the sensitivity and accuracy of their readings.
This has led many women to ask questions like, ‘how accurate are pregnancy tests’, ‘can I trust the results’, and ‘how early can you detect pregnancy with an at-home test’. Let’s first look at how pregnancy tests work before addressing their accuracy and how early you can test for pregnancy.
How Pregnancy Tests Work
Even the earliest pregnancy tests worked by analyzing hormone levels. In particular, these tests detected whether or not human chorionic gonadotropin (hCG) was present. This type of test is still used today, and operates in the same fashion. When a fertilized egg attaches to the uterus, the developing placenta causes hCG to be released. The hormone then becomes detectable in urine and blood.
There are three types of pregnancy tests:
Test Strip Tests – The test strip should be immersed in a urine specimen for approximately 5 seconds then removed. A positive result will begin to show almost immediately while negative results can be verified within 5 to 10 minutes.
Cassette Tests – Cassette style tests use a small sampling of urine, usually three drops, placed directly on the tester. This test will determine whether or not a woman is pregnant in a matter of minutes.
Midstream Tests – Midstream tests are the simplest types of pregnancy tests. This test is a one-step process that takes approximately 5 minutes to provide results.
Pregnancy tests will provide a positive, negative or invalid result. Should an invalid or negative result occur, follow up with another test within a few days is recommended.
How Accurate Are Pregnancy Tests?
Of course, the most important concern is accuracy. There are a couple of factors that influence how accurate a pregnancy test can be:
The Sensitivity of the Test - The more sensitive the test is to reading low levels of hCG, the more accurate the results will be.
Time Since Pregnancy Occurred – The longer the period of time is between conception and testing, the more accurate the results will be because more hCG will have accumulated, doubling about every two days.
Typical pregnancy tests are about 97% accurate. While these tests are highly trusted, there are advanced pregnancy tests that produce even higher accuracy rates. Among these options is Medical Disposals’ Ultra Sensitive Pregnancy Test Strip, which is 99.9% accurate. It can accurately detect levels of just 10 miu/ml hCG.
When is the Earliest a Pregnancy Test Will Work?
As mentioned above, hCG is the pregnancy indicator. The placenta, which produces hCG, begins developing about six days after the fertilized egg implants. Implanting can happen on the day of intercourse, or within a few days afterwards. The earliest that hCG can be detected is typically 7-9 days after intercourse.
Pregnancy tests will vary when it comes to accuracy as it relates to the scale of time. Most women wait until after they have missed the first day of their menstrual cycle, but there are tests that can detect pregnancy days earlier. Ultra-sensitive tests can provide accurate results as soon as 8 days after the ovulation date, whereas standard pregnancy tests should produce highly accurate results 12 days after ovulation.