So you think you might be pregnant. Naturally, you saunter on down to the pharmacy, pick up a quick urine test and voilà: you’ll soon know whether you have indeed got a human developing inside you.
However, the pregnancy tests you’re thinking of right now are relatively new inventions. So how on Earth did women originally test to see if they were expecting? As it turns out, older “pregnancy tests” were far more bizarre and surreal than you’re probably imagining. So hold off on any food you might be about to consume – things are going to get a little weird.
It’s All About Number One
So, first off, a little context. When a woman becomes pregnant, the hormone levels in her body change. During the onset of pregnancy, a hormone called human chorionic gonadotropin (hCG) is produced by a section of the placenta. It acts with other parts of the body to help maintain the corpus luteum, a feature that develops each time a menstrual cycle begins. It also triggers the production progesterone, a multipurpose hormone that, among other things, helps maintain the pregnancy, particularly in the early stages.
A contemporary pregnancy test looks for signs of elevated hCG in the woman’s urine any time from six days after fertilization occurs. They are incredibly accurate (99 percent), with very few “false positive” results. Some look for multiple hormones produced during pregnancy, rather than just hCG.
There was a time when the urine of suspected pregnant women was analyzed not by medical doctors or high-tech pregnancy tests, but by “prophets.” In the 16th century, European women were often foisted before these “experts” who, by peering deep into their sickly yellow streams and considering the tones, hues and smells of the pee, claimed they could ascertain whether or not a baby was on the way.
As part of this hands-on procedure, the more advanced prophets mixed urine with wine. Although they probably weren’t sure why it was happening, there was some scientific truth to this: Alcohol reacts with specific proteins produced during pregnancy, so the consistency of the pee would change.
This technique of examining urine – “uroscopy” – dates back to ancient Babylonia, and it was brought to the fore in Byzantine medicine, part of the advances of the Eastern Roman Empire from the 5th century to the mid-15th century.
Pee Like An Egyptian
Urine tests go way back, though, emerging long before the time of the Protestant Reformation or Copernicus. In the 14th century BCE – over 3,350 years ago – ancient Egyptians had a technique all of their own.
During the reign of Pharaoh Akhenaten, married to the infamous Queen Nefertiti, Egyptians sprinkled a woman’s urine on wheat and barley seeds. If they sprouted, she was said to be pregnant. The wheat sprouted if she was pregnant with a girl; the barley if it was to be a boy.
Remarkably, this technique was shown to work, at least in terms of detecting a general pregnancy. Although they probably didn’t know it at the time, the hormones produced during pregnancy would actually encourage these seeds to sprout.
Hippocrates, the father of “modern” medicine, incorrectly assumed that you could detect pregnancy by inserting an onion into a woman’s vagina. If the woman’s breath smelled of onions the next morning, she wasn’t pregnant: This was based on the idea that a woman’s womb would be open without a baby growing inside it, thereby acting as a wind tunnel from rectum to mouth. If there was a baby-shaped obstruction in the womb, then her breath wouldn’t smell of onions.
Suffice to say, this isn’t medically accurate.
The Circle of Life
The hormone hCG was identified by medical researchers for the first time in the 1920s, opening up the possibility of detecting it to determine pregnancy status. The hi-tech pee sticks we have today weren't available, so what did they use instead? Unfortunately for certain members of the animal kingdom, they would provide a slightly grim detection tool in this regard.
A sample of the woman’s urine was injected into an immature female mouse. If the hCG hormone was present, the animal would go into “heat” – essentially, becoming sexually active and ready for copulation. Initially, only mice were used, dissected post-injection so that their ovaries could be examined; within a few years, rabbits were used instead. This test was named after the lead researchers: the Aschheim-Zondek, or “A-Z,” test.
Incredibly, this test was 98 percent accurate. However, the results took several days to come in, and the test could not distinguish between hCG and a type of fast-growing cancerous tumor called a chorioepithelioma. Inadvertently then, this test also served as a cancer detection method – assuming the patient wasn’t also pregnant at the time.
In Plain View
Image credit: A Xenopus laevis from Zimbabwe. Wikimedia Commons; CC-BY-2.0.
Advancing on this technique, a scientist named Lancelot Hogben in Cape Town, South Africa, spent his time experimenting on clawed frogs with various human and non-human hormones. The benefit of amphibians over mice and rabbits in this regard is that their eggs are much easier to examine.
As it turned out, the South African clawed frog, Xenopus laevis, was particularly useful for human pregnancy tests. If the female was injected with a pregnant woman’s urine, it would lay eggs before the end of the day. Conversely, the male would respond by producing sperm. This far more rapid and accurate test spread through Europe in the 1930s, and it became the standard bearer.
Image credit: The science of pee. Gotzila Freedom/Shutterstock
In 1976, a drug manufacturer company called Warner-Chilcott developed a $10, two-hour testing kit that women could use in the privacy of their own home – no frogs required. The test was 97 percent accurate for positive results, cheap and easy to use. This revolutionized the industry, and served as the basis of the pregnancy tests people use across the world today. This in itself was an advancement from the early 1970s, where radioactive labels were used to pick up on the hCG hormone.
So, although the technology has come a long way since Queen Nefertiti’s time, we still do detect pregnancy by peeing on things.