A pregnancy test is used determine if a woman is pregnant or not. Today, we know that any test that detects the hormone, hCG, will offer the quickest and most accurate solution for determining if you have a baby on the way. hCG is secreted by the placenta right after a fertilized egg implants in the uterus and this hormone will show up in both your urine and in your blood. Urine pregnancy tests are great for convenient home use; but your doctor may opt to use urine or blood, as the latter can provide a “quantitative” hCG number. Both methods are quite reliable, highly accurate.

The history of the pregnancy test is an interesting one, and is naturally colored by myth, wives’ tales, and folk hypotheses. And though “ancient” pregnancy tests were typically based on false assumptions or pseudo-science, the ancient Egyptians at least knew where to start looking: they considered a woman’s urine to be the best source for prognosticating a pregnancy. To this end, the ancient Egyptians were purported to mix urine with various grains; if the grains germinated, you had a positive result, and depending on which grain germinated, you could also determine the gender: a two-in-one pregnancy and gender test! Fortunately, the Egyptians did not spend very much on patenting this technique, as it turned out to not provide very accurate results…

The Middle Ages brought us slightly more empirical techniques, though the science was still off a bit. Various physicians would closely analyze (describe) a urine sample or mix it with wine or alcohol to determine a pregnancy result. Of course, during the Middle Ages, the body was thought to be governed by the four humours (the fluids that corresponded to our “four natures”), and not influenced by hormones. So urine was studied and interpreted in the same way tea leaves might read the future – solely on the basis of how it looked. And while the descriptions of various urine results are quite detailed, it’s likely that the Renaissance pregnancy test was not very reliable either. A “smart” doctor might inquire about a few other physical symptoms in order to sharpen the accuracy of his urine prophecy.

As might be expected, the Age of Reason brought more rational and scientific approaches to detecting pregnancy. But while much was learned about the physiology of reproductive systems, the discovery of a hormone-driven reproductive system was still a century or two away. Instead, medical science developed increasingly sophisticated analyses of pregnancy symptoms as well as a clearer understanding of the male and female body. Still, pseudo-science reigned, and despite the fact that anatomy books were quite detailed and exact, nothing could prevent odd theories and practices from developing. For example, doctors still analyzed urine, but this time rather than try to determine pregnancy by changes in urine color, sheen, or consistency, or how it might mix with alcohol, they focused on the presence of bacteria or crystalline structures (viewed through the microscope). And while giant steps in pregnancy test research were not achieved until the 20th Century, the 19th was noted for more important progress in prenatal health, hygiene, pregnancy care, and overall reproductive and infant wellness.

About 100 years ago, the first major steps were made in developing the modern pregnancy test. So while we map out the human genome today, a century back researchers were mapping out how hormones worked during the different phases of a woman’s menstrual cycle. This finally led to the discovery of human chorionic gonadotropin hormone, or hCG, around 1925. Here, significant amounts of hCG were only found in pregnant women, meaning that science had finally found a reliable, empirical marker (or detectable substance) that could be used for testing purposes.

This discovery, however, was not good news for the baby rabbit, mouse, or rat. That’s because hCG, when injected into one of our fuzzy friends would do a number of things. For a young, sexually immature rat or mouse, the presence of hCG could cause them to “be in heat”. Later, researchers found out that injections of hCG in rabbits, rats, and frogs would cause ovulation. Therefore, you could inject a urine sample from a human woman into a rabbit to find out if she was pregnant – this is the rabbit test you have always wondered about. The problem for the rabbit was that this testing method required the bunny to sacrifice his or her life in the name of determining a test result. Fatal surgery was required. Fortunately, pregnancy testing during the rabbit era was not popular or widespread; moreover, the results were not accurate either. References to the rabbit test are still current in popular culture, from an episode of the TV show MASH, to Aerosmith song lyrics, and a Billy Crystal movie from the 1970s.

At any rate, by the early 60s, new research on hormones were yielding better methods for finding out if a woman was pregnant. A precursor to our modern pregnancy test technique appeared when researchers used anti-hCG antibodies to facilitate a diagnostic reaction. While this method yielded better results, there were still some problems: cross-reactivity with medications or other hormones (like LH) which caused false negative or false positive results. The problem with LH (luteinizing hormone) is that it is often present in a woman’s urine throughout her cycle, at least in low levels. It reaches particularly high levels right before a women ovulates. Hence, false results were a problem during this era.

By the early 1970’s, a woman could collect a urine sample at home and either bring it to the doctor for analysis or send it via mail to a laboratory. Unlike today’s quick and easy one-step pregnancy tests, early diagnostic kits were composed of solutions, test tubes, and many other components. These were only to be used by doctors or medical professionals. This, of course, changed, and the first home pregnancy test hit the market in the late 70s. Nevertheless, a woman was still required to mix her urine with solutions using test tubes – and the procedure was still rather complex, requiring a few hours for the result to appear. Accuracy rate were not quite as impressive as with today’s test, and false negative results were relatively common.

From here, improvements were made throughout the 1980s and 90s, and pretty soon the “home chemistry” mixing-mess was ancient history, as well. Tests were created in one-step formats in which the testing reagent could be contained on a single “strip” – and situated within a hand-held applicator. Urine would be absorbed through the test – through the anti-hCG antibodies – and across a control line (color band) that would appear if the test was used properly. A color band or plus sign, etc, in the test area of the strip would indicate a positive result with ten minutes or so. Test sensitivity also increased. Not long ago, manufacturers required that you wait up to two-weeks after a missed period before beginning to test. More sensitive tests decreased the wait-time to just after your missed period, and more recently, some high-sensitivity products indicate that they can detect pregnancy before a missed period (around eight to ten days after a woman ovulates). When can I test?

Today, a wider array of testing options are available for women. Digital pregnancy tests were the first innovations of the 21st century, along with clinical-style testing strips that are both highly accurate (offering early-detection) and quite affordable. Early-Pregnancy-Tests.com, the leading Internet vendor of home pregnancy tests, appeared on the scene in 2001 to help women to take charge of their fertility with a wide selection of preconception products and articles like this one! Together, we’ve come a long way in just thirty years. And best of all, the martyrdom of rabbits is no longer required.

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