Until the 20th century, knowing if a woman was pregnant was more of an art than a science. The menstrual delay, the physical symptoms and the doctor’s opinion were combined, and it is not uncommon for conclusions to arrive late, when no one had any doubt.
From the 1920s, the first modern biological tests appeared, based on injecting women’s urine into animals such as frogs, mice or rabbits to detect the presence of the pregnancy hormone, HCG.
Before the blue line
It was science, but bloody science, slow and expensive: it required laboratories, animals and specialized personnel, so the result took days and always passed through medical hands. The idea of designing a test that a woman could do alone at home seemed, in this context, almost as far away as a video call.
The paradigm shift began in the 1950s and 1960s when immunological techniques made it possible to directly detect HCG in a urine sample without the use of animals. In 1960, Leif Wide and Carl Gemzell developed a hemagglutination inhibition test that mixed urine, anti-HCG antibodies, and red blood cells, so that in the event of pregnancy, the cells would clump together in a characteristic pattern. It was faster and cheaper than older biological tests, although it was still not very sensitive for detecting very early pregnancies and there was some interference with some medications.
The introduction of radioimmunological tests in the early 1960s made it possible to measure HCG with greater precision, but at the cost of sophisticated equipment and radiation protection measures, which was unthinkable outside of a good laboratory. Science already knew how to “see” pregnancy in a test tube, what was still missing was to reduce this entire process down to a small kit that could be handled in the bathroom at home.
A designer in the wrong place
In 1967, Margaret M. Crane was 26 years old and working as a graphic designer and publicist, not a scientist. At that time, she was making her living at Organon, a pharmaceutical company in New Jersey, designing a line of cosmetics. One day they showed him the laboratory: rows of test tubes on small mirrors, with urine samples patiently awaiting their chemical verdict. Doctors sent the samples to the laboratory and, after mixing the reagents, a red ring at the bottom of the tube revealed whether there was a pregnancy; Of course, the response could take up to two weeks to reach the woman.
Crane looked at the scene with the eyes of a designer, not a biochemist, and thought of something devastatingly simple: It’s so mechanical a woman could do it at home. He had no formal scientific training, but he possessed a powerful intuition, woven from a very precise observation: waiting, mystery and medical dependence were as much a human problem as a technical one.
Kitchen prototype and clip box
The germ of the first modern household pregnancy test was born not in a laboratory, but on the kitchen table of Crane’s New York apartment. What he had on hand was not sophisticated equipment, but everyday objects: a plastic clip box caught his attention with its shape and size. He cut a strip of Mylar, a reflective film, and glued it to the bottom of the box, creating a small makeshift mirror.
Then he placed a test tube inside and added a pipette to introduce the urine. The principle was the same as in the laboratory: if a red ring formed at the bottom of the tube, the mirror would make it visible without it being necessary to handle the tube or have special facilities. Crane named his invention “Predictor” and, with this homemade prototype, he demonstrated that the test logic could be compressed into something manageable, discrete and, above all, private.
The “no” of companies and the fear of autonomy
When Crane presented his proposal to Organon executives, the reaction was not enthusiasm, but panic. They feared losing the income of doctors who sent the samples to the laboratory, they feared that women “would not know how to handle” the results, and they suspected that rapid access to information would increase the number of abortions or “poorly controlled” decisions. In short, the problem was no longer technological but moral and economic.
However, Organon’s Dutch parent company saw market potential in testing the test outside the United States. A market test was carried out in Canada in the early 1970s, where Predictor was launched in 1971 as an innovative product promising answers “fast, at home and in private”.
Early user testing wasn’t as immediate or as compact as current strips, but they already shared their core logic. The user collected the urine in a small container, added a few drops to a tube containing reagents and waited for the immunological reaction to reveal the presence of HCG through a visible change, in this case the famous colored ring.
The waiting time at that time could be around two hours and the interpretation required a certain care, but the great revolution was not in the absolute speed, but in the change of scenery: from the hospital laboratory to the toilet counter. Immune technology, originally designed for specialized diagnostics and even to detect HCG-producing tumors, has been transformed into an instrument of self-care.
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