If you think reading that little pink or blue line is complicated, you’ll really feel for the women of yesteryear. Here are 15 interesting facts about pregnancy tests.
All tests do the same thing
Americanpregnancy.org tells us all pregnancy tests measure for the placenta-producing hormone known as human chorionic gonadotropin (hCG), so whether you go the Clear Blue or e.p.t. route, they all do the same thing (aside from a difference in the way the results come in).
How early can they work?
Healthgoesfemale.com says the hormone hCG can be detected as early as six days after an embryo has been planted in your uterus.
Testing too soon after missing your period can lead to false negatives. Even testing within just seven days of ovulation can give you a false negative result. Babycenter.com tells us that 9 out of 15 women receive a false negative until 7 to 8 weeks into pregnancy.
Healthgoesfemale.com says that false positives are pretty rare and far less common than false negatives. So if you get a positive, chances are you really are pregnant. If you get a negative, you may still want to test a couple more times.
The best day to test
If you want to test as early as possible but want to make sure you’re getting the most accurate results, test the day your next period is supposed to begin—you have a 99 percent chance of getting an accurate read on most tests then according to TheBump.com.
If you’re patient…
Healthgoesfemale.com tells us f you wait until your period is a week late, the accuracy rate on most tests goes up to 97 percent.
When to pee: part I
If you’re testing before your period is due, Healthgoesfemale.com says it’s best to do so when you haven’t peed for at least four hours. Your urine will hold the highest concentration of hCG.
When to pee: part II
For even more accuracy, Healthgoesfemale.com says to use midstream urine—this holds the highest level of concentration of hCG. In other words, pee for a couple of seconds before getting the stick in there.
The first test
The first urine-based test dates back to 1350 BCE in ancient Egyptian society. According to Mom.me, the first test involved a woman peeing on wheat and barley seeds over several days. The growth of the barley seeds was supposed to indicate that a woman was pregnant with a boy; growth of the wheat indicated a woman was pregnant with a girl.
And the first test was on to something…
Nih.gov explains that much later in history — 1963 to be exact — researchers found that the urine of pregnant women did in fact promote seed growth–70 percent more than the urine of men and of women who weren’t pregnant. This may have been the first test that found elevated levels of estrogen in a pregnant woman’s pee.
Sitting on a date?
Not that kind of date. According to Mentalfloss.com another ancient Egyptian test involved a woman sitting on a bunch of mashed up dates and beer. If she threw up a lot, it was assumed that she was pregnant. This test was also on to something because pregnant women are particularly sensitive to bad odors.
In the mid-1500s, something called a pee prophet existed. Mom.me explains that a pee prophet was someone who allegedly could tell if a woman was pregnant by looking at her urine. Apparently the urine of a pregnant woman is pale yellow with a fog in it.
Rats or mid wives?
Nih.gov says that in 1927, rats and mice were used to figure out whether or not a woman was pregnant. If a woman suspected she was pregnant, a doctor would inject some of her urine into an immature rat or mouse. If she was, the mouse or rat would go into heat, in spite of the fact that it was too young to do so.
Eyes and pregnancy
Nih.gov also tells us that one 16th century physician said you can tell if a woman is pregnant based on her eyes. Jacques Guillemeau claimed that a pregnant woman’s pupils shrink and she gets veins in the corners of her eyes. This test isn’t accurate, but he was picking up on something since a woman’s vision can change during pregnancy.
Is your vagina changing colors?
Very early on in pregnancy—around 6 to 8 weeks in—your vagina can take on a dark blue or purple and red hue. According to Mentalfloss.com no one noticed this until the late 1800s because until then, doctors were too conservative to look at a woman’s vagina.