A long, long time before women peed on sticks, they peed on plenty of other things. The name changed, and the tools changed. And what also changed, most significantly, was who got to play the part of the prophet. Doctors in the 18th and 19th centuries, shaped by the scientific discourse of the Enlightenment, abandoned the belief that urine could simply be eyeballed, instead pursuing the idea that it must contain some less easily identifiable traits—some bacteria or crystal structure, visible only under a microscope—that could signify a pregnancy.
Around the end of the 19th century and the beginning of the 20th, scientists began to discover the chemicals that regulated various functions in the human body, including reproduction. In the s, scientists ditched the animals entirely, turning instead to immunoassays, or tests that combined hCG, hCG antibodies, and urine—if a woman was pregnant, the mixture would clump together in certain distinctive ways. While women no longer needed a frog or a rabbit, though, they still needed a doctor.
Crane was a freelance graphic designer at a pharmaceutical company when she noticed a line of test tubes over a mirrored surface. When she asked what they were, she was told they were tubes filled with urine and reagents that would eventually show a red ring that was reflected in the mirror. The simplicity sparked something in Crane, who went home and started to experiment. They had to inject five mice per woman and wait about a week before getting the result.
And even then, they could only detect the high levels of hCG that women have starting around 2 weeks after a missed period. In addition, the use of so many animals made it so that the test was expensive and relegated it to a few labs that received shipments of urine through the mail.
But up through the s, women had to wait until at least a month after conception, visit a doctor, mail her urine to a lab, and then wait at least another week to get the result of the test. Unsurprisingly, pregnancy testing in this era was not routine , used only by those who were wealthy or needed to know if they were pregnant for medical reasons. The juvenile mouse test was slightly improved in by an American doctor, Maurice Freidman, who swapped juvenile mice for adult rabbits , which were easier to inject.
However, a test using frogs, developed the British scientist Lancelot Hogben , marked the pinnacle of these animal tests. This test also gave results faster: within twelve hours.
The frog test increased the availability of pregnancy testing, but it still required shipping urine to a select number of frog labs. Tens of thousands of frogs were injected with urine throughout the ss, but pregnancy testing in this era was still not the norm.
Most labs would only test urine sent by a doctor, meaning that women had to rely on their doctors to get tested. And many doctors—and health insurance companies—would only grant a woman a test if she had some urgent medical reason that she needed to know she was pregnant.
Most women instead relied on morning sickness and sore breasts as early clues to their pregnancy, not visiting a doctor to confirm until months after conception.
At first, these tests had similar sensitivity for hCG, but by the early s , Drs. Vaitukaitis, Braunstein, and Ross had developed a test that could detect pregnancy just weeks after conception —on the first day of a missed period. These new tests used antibodies. Antibodies are molecules that recognize and stick to other molecules. In pregnancy tests, however, scientists engineered antibodies that recognized and stuck to hCG.
They then mixed these blood cells with the other test components: hCG antibodies and urine. Based on the way that antibodies stick to hCG and to each other, the hCG-decorated blood cells would clump if they were mixed with the urine of a woman who was not pregnant.
On the other hand, if the blood cells and hCG antibody were mixed with the urine of a woman who was pregnant, the blood cells would not clump. So by looking at the clumpiness of the blood cells, doctors could tell if a woman was pregnant Figure 3. These and other, similar antibody-based tests could give doctors results in a few minutes to hours and finally made pregnancy testing mainstream. At first, women still had to visit their doctor to get a pregnancy test.
But that, too, changed in the s in Canada, in the US when the first at-home pregnancy test hit the market , using this same blood-and-antibody technology. Besides, she said, every insert to the kit urged women, if they were pregnant, to immediately see a doctor for care. Having such knowledge earlier changed pregnancy itself, says Lord. This is an invention developed by someone to be marketed, and it really changes how people view pregnancy. Roger Catlin is a freelance writer in Washington D.
The design for Margaret Crane's prototype home pregnancy test kit was inspired by a transparent plastic paperclip container. Brendan McCabe It was once a test conducted by doctors, requiring an appointment for an office visit.
The first consumer product from Crane's prototype was the "Predictor," which was manufactured in Canada in
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