The history of pregnancy tests

The history of pregnancy tests Part 2: From antibodies to the at-home test

We already dove into the world of “Piss prophets” and lab rats (and frogs) in Part 1, but there’s still some ground to cover until we get to the modern, at-home pregnancy test. 


Bah, bah...Sheep’s blood

Scientists came up with a way to detect pregnancy two to three weeks after conception and cut down the wait time for results to minutes or hours in the early 1970s. This test relied on antibodies, molecules that “locate and attack ‘foreign’ proteins.” For pregnancy test purposes, scientists engineered antibodies to recognize and “stick” to the hCG pregnancy hormone. 

“Scientists attached hCG to the outside of the sheep’s blood cells, decorating the blood cells with hCG. They then mixed these blood cells with the other test components: hCG antibodies and urine,” a Harvard University article explains.

The mixture would become clumpy if the urine from a non-pregnant person was added. But if the mixture didn’t clump, it meant the person was pregnant. This kind of testing wasn’t perfect, “as hCG could easily be confused for other similar hormones,” resulting in false positives. And despite faster test results in the lab, they would still have to be sent back to the doctor’s office before a patient could get them.


Cutting out the middleman

One woman came up with a way to skip the doctor’s office altogether. Margaret Crane, a product designer at Organon Pharmaceuticals, came across the pregnancy tests that were being done at the company’s lab in New Jersey. Doctors sent in the urine samples and the results were sent back weeks later. It got Margaret thinking, why can’t the test be done in the privacy and comfort of your own home? She decided to create her own prototype, massive in comparison to today’s sleek tests. She received a negative response from her employer. They said the product would make doctors “seem less necessary.”

She said, at the time, she was “absolutely certain” the test would be useful and “that a woman should have the right to be the first to know if she was pregnant, and not have to wait weeks for an answer.” 

The Predictor, the first at-home pregnancy test, was issued a patent in 1971. The instructions included 12 steps and a two-hour wait time. It was available in Canada in 1971 and in the United States by 1977.


Pee on a stick or take a dip

The “wand” or stick pregnancy test hit shelves in 1988. Unilever came out with the Clearblue Easy, named for the two stripes that would appear in the case of a positive test. This kind of test used hCG antibodies, but rather than mixing them with blood cells, they relied on molecules that would be activated with dye. Both stick tests and strip tests (like the ones at Ovry) use a strip coated with molecules. When a pregnant person’s urine flows over the stick or when the strip is dipped into a container of urine, the dye changes. 

For more than 3,000 years, humans have been coming up with ways to detect pregnancy. Now, there are dozens of options available. But with all of the choices out there, we still like to think we offer the best test for you and for the environment: sustainable, affordable and delivered right to your door. 


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