Walk through the aisles of any American drugstore, and you’ll eventually encounter the home pregnancy test section. Because of the ease, convenience, and relative affordability of these tests, the majority of Americans now find out they’re pregnant in the privacy of their own bathrooms. The home pregnancy test is undoubtedly a success story. You can buy them in every drugstore, many grocery stores, and online in packs for as little as $1 per test. Scanning the aisles of a local drugstore, it seems like the competition between brands focuses on which test can tell results the earliest, which test provides the clearest results, and which test is most accurate. But what happens when the competing forces of capitalism embrace the home pregnancy test? Women’s emotional health, as well as knowledge about their reproductive bodies, is often sacrificed.
Today, many home pregnancy tests advertise that they can tell a woman she is pregnant six days before a missed period. What happens inside a woman’s body six days before she is pregnant? Pregnancy technically begins when a fertilized egg implants into the uterus, which can take three to four days after fertilization. The entire process from fertilization to implantation is not consistent and can take as few as 8 days and as many as 12 days. Half of all fertilized eggs pass through the uterus during menstruation, either only partially implanting or not implanting at all. Therefore, six days before a period begins, a woman could have a blastocyst that has implanted and started the process of becoming an embryo or she could have a fertilized egg still in the process of almost implanting. In the former case, a home pregnancy test, which detects HCG, a hormone that a woman only starts producing after implantation, would be positive. In the latter case, the pregnancy test would not detect HCG and the test would be negative, even if implantation occurs the next day.
Given these various scenarios, a negative pregnancy test result could be wrong because the test was taken too early, despite the optimistic promises advertised on the box, and a positive result could be wrong because it detects a very early pregnancy that doesn’t develop, otherwise known as a chemical, or biochemical, pregnancy. Some studies suggest that nearly 75% of pregnancies end this way. Yet, the majority of home pregnancy tests claim to be over 99% accurate, despite the uncertain status of very early pregnancies.
The home pregnancy test didn’t start as confidently. The first tests to detect HCG in a pregnant woman’s urine were developed in 1927, but each test required injecting a rabbit (or mouse) with the woman’s urine to determine whether the hormone was present. If the woman was pregnant, the rabbit’s ovaries would swell in response to HCG. However, to determine whether the ovaries reacted required killing the animal. This made the test costly and messy for use outside of a specially equipped laboratory.1 It took more than 30 years for scientists to develop a test that could be done without an animal and in a doctor’s office. In 1960, a test was created that still required test tubes but could be performed outside a laboratory; the results, however, were harder to read than current pregnancy tests. Almost immediately, however, pharmaceutical companies began working on simplifying these tests for consumer use. The earliest prototypes of home pregnancy tests were not nearly as reliable as current models and quite a bit more complicated to use. The test results often took more than an hour, unlike current tests that can give a result within minutes. Therefore, initial adoption of the home pregnancy test was reluctant and slow. For example, in the U.K. in 1984, studies suggested that only 55-60% of women knew they existed, and only 10- 12% of women used them.2 According to the same article in The Chemist and Druggist citing those statistics, the first developed home pregnancy test was available in the U.K. for five years before magazines decided to advertise its availability.
However, once adopted, the invention of the home pregnancy test was in many ways just as revolutionary as the birth control pill in helping women control their reproductive lives. It allowed women to see what was going on inside their bodies before they could feel any effect from pregnancy. For the first time, in 1971, and then more widely by 1978, women could discreetly go to their local drugstore, pick up a boxed pregnancy test, and in the privacy of their bathrooms, pee in a cup and wait for just an hour to know whether they had potentially life-changing results.3 For the most part, these tests have allowed women to make better-informed decisions and to feel more in control of their future. If the pregnancy is unwanted, it allows women more time to schedule an abortion or to have one discreetly. These tests created one more dent in a paternalistic medical culture where doctors controlled knowledge about women’s reproductive lives.
Yet, even as women have been given access to this impressive medical technology, the education about how conception works, how their bodies reproduce, and, importantly, how so many things can go wrong before a baby is created, is so very often lacking. While the home pregnancy test has undoubtedly helped women retain some control after accidental pregnancies, many women use home pregnancy tests because they’re eager to discover that they are in fact pregnant. Those boxes advertising how early a pregnancy can be detected are primarily aimed at women who want to be pregnant, and that’s where the problems begin.
Twenty years ago, before the sensitive pregnancy test became so ubiquitous in drug store aisles, the majority of women would never discover an early pregnancy loss, or a biochemical miscarriage, often defined as happening before a heartbeat can be detected. In the majority of cases, women might experience their periods as being a few days late, and then they may have some bleeding that could be heavier than normal, depending on their cycle. In some cases, knowledge of recurrent biochemical losses could be welcomed as they may indicate an underlying medical condition, but more commonly, they don’t happen recurrently and are a body’s healthy way of aborting a blastocyst or embryo with genetic abnormalities not compatible with life. A biochemical loss is a positive evolutionary trait, and in no way does it suggest a woman won’t be able to conceive successfully in the future. However, when a woman sees a positive pregnancy test one day, and then starts bleeding the next, that information is usually not readily available to her. She reads the experience as loss that might be tinged with anxiety about her future reproductive ability.
Additionally, when advertising for home tests boast results “six days before a missed period,” there is an assumption that periods always run on regular and predictable cycles, and that fertilization and implantation also work on an exact clock. In reality, many women have cycles that may vary by several days each month, and even the woman with the most clockwork cycle, might find that fertilization and implantation don’t follow the optimistic time frame displayed on these boxes. We tend to talk about pregnancy with definitive numbers: it lasts nine months; it takes two weeks after ovulation for fertilization to occur; a heartbeat can be detected as early as six weeks in the pregnancy; due dates are calculated based on 28-day menstrual cycles. In reality, all these numbers are approximations. None of them are exact.
Why market these tests to women with inflated, often unrealistic, promises? The marketing sells, of course, but at a cost. It presents normalized assumptions about the ways women’s bodies should function, and without more education about how reproduction works, the tests can easily be misinterpreted to produce anxiety about the internal workings of our bodies.
- See Leavitt, SA. “‘A private little revolution’: The Home Pregnancy Test in American Culture.”Bulletin of the History of Medicine 80, no. 2 (2006): 317–345. Return to text.
- Unauthored, untitled. The Chemist and Druggist, December 1, 1984. Return to text.
- Robinson, Joan. “Bringing the Pregnancy Test Home from the Hospital.” Social Studies of Science 46, no. 5 (2016): 649- 674. Return to text.