How a Frog Became the First Mainstream Pregnancy Test
A pregnancy test works by detecting the hCG hormone, which is usually only present in your body if you’re pregnant. A positive result—even a faint line—on a pregnancy test means you’re almost certainly pregnant.; False positive results are incredibly rare, and only happen if you have recently been pregnant, you’re on fertility medications containing hCG, or you have a rare medical. A qualitative pregnancy test only gives a positive or negative result and often requires a higher level of pregnancy hormone than many at-home early pregnancy tests. Quantitative pregnancy tests can sometimes detect pregnancy hormone before an at-home test can.
The African clawed frog, Xenopus laevisis a palm-sized, greenish-gray animal that hails from the ponds and rivers of sub-Saharan Africa, where it lived for millions of years without anyone injecting it with urine.
That unbroken streak what is the current mortgage lending rate in the s, thanks to a British scientist with the fantastic name of Lancelot Hogben. Hogben was a talented but irascible zoologist with strident left-wing politics and penchant for burning bridges. In his early career, he studied hormones by injecting them into frogs, and when he moved to South Africa inhe continued those experiments with the local amphibians.
One of them— Xenopus —was so abundant and easy to work with that Hogben spent much of his time with the creature, and even named his house after it. In response, the frog started laying eggs. This accidental finding was a fortuitous one. At the time, scientists knew that the urine of pregnant women contained hormones that were made in the pituitary and that affected the development of ovaries. If those same hormones could trigger egg-laying in Xenopusperhaps the frog could act as a living pregnancy test.
Disenchanted with racism in South Africa, he returned to Britain shortly after his seminal experiments and brought a colony of Xenopus with ppsitive. His colleague Charles Bellerby worked out how to raise preghancy frogs appropriately, showed that they would reliably lay eggs when exposed to the urine of pregnant women, and confirmed that when they're not mating, they don't lay eggs spontaneously.
Another team from South Africa had been doing similar work, and as academics are wont to do, the two groups developed a bitter feud. It was never truly resolvedalthough Hogben could be said to have won, since the test that resulted from this work took his name. Then, wait. If the woman is pregnant, between five and 12 hours later, the frog will produce a cluster of millimeter-sized, black-and-white lregnancy.
The results were reliable. One researcher reported that after injecting frogs, he never got any false positives and only missed three actual pregnancies. A later version of this test used rabbits instead of mice.
In truth, the rabbits always died, because, like the mice, they had to be dissected to check the size of their ovaries. This meant that testing for pregnancy was laborious, expensive, and bloody work. Kknow comparison, the Xenopus test was faster, simpler for practitioners, and much easier on the animals. They were also easy to get.
And so it was that tens of thousands of frogs were infused with human urine between the s and s. In the s, scientists developed chemical tests that searched directly for human chorionic gonadotropin hCG —the tell-tale hormone that the frogs were reacting to. The frogs were slowly abandoned. But according to medical historian Jesse Olszynko-Grynthey were the innovation that turned pregnancy-testing into a large-scale activity. He wrote:. Although facilities existed, getting a test was neither a rite of passage for the expectant mother nor an aid to the woman who wanted to terminate an unwanted pregnancy.
Rather, laboratory tests were mainly reserved for use in urgent, medical-priority cases that required differential diagnosis — for example, to distinguish the growth of a normal fetus from that of a tumor.
Doctors, not women, controlled pregnancy testing and they were not keen on making what type of dress to wear to a beach wedding laboratory service available to every woman on demand.
If a prsgnancy sent her own urine specimen to a laboratory it would not be tested, and if she went how to say number one in german her family doctor she might well be told to return in a couple of months when the ptegnancy signs of an advanced pregnancy were apparent.
If Prgnancy changed pregnancy testing, then pregnancy testing also changed Xenopus. With large stocks of Xenopus popping up around the world, scientists started using the animal for other lines of research.
It has been repeatedly used to study how cells work and how embryos develop. It has flown into space. It was one of the very first back-boned animals to be cloned —a feat that led to a Nobel Prize. Bd has now spread across six continents and has killed countless populations of frogs in its wake. Weldon and others believe that the international trade in Xenopusfor either pregnancy testing or lab research, could have triggered this amphibian apocalypse. For that reason, 11 U. Also present were three other people, one of whom had recently gone through IVF and genuinely wanted to know if she was pregnant.
Kirksey has tried to stage several such experiments in recent years, with varying degrees of success. One was cancelled after protests from animal-rights campaignersand another was disrupted by an audience member who tried to rescue the frog. But on August 29, things went smoothly. Kirksey injected Loretta—and nothing happened. Later, the would-be mother peed on three modern pregnancy tests, which turned up negative.
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An ultrasound wouldn’t detect a fetus, but your body produces the hCG hormone so the result would be positive. Unless you took a pregnancy test, you wouldn’t know you had been pregnant, as a chemical pregnancy will show very few symptoms, and you wouldn’t experience pregnancy-related signs like morning sickness. Many experts think that. May 04, · The “Hogben test” was simple. Collect a woman’s urine and inject it, fresh and untreated, under the skin of a female datingfuckdating.com, wait. If the woman is pregnant, between five and 12 hours.
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It's normal for a positive pregnancy test to bring about a variety of emotions, worries, doubts, and anxiety. Try to take a few deep breaths.
Whether this was a planned pregnancy or not, there are some important next steps you should think about and take. If, like many people, you're not sure what these next steps are, here's a handy list of things to do when your pregnancy test is positive. Watch all episodes of our Stay Calm Mom video series and follow along as our host Tiffany Small talks to a diverse group of women and top doctors to get real answers to the biggest pregnancy questions.
Call for a prenatal appointment as soon as your pregnancy is confirmed or you suspect you are pregnant. Some practitioners may not schedule the first appointment until after you have missed two periods, while others have you come in right away. Even if you don't have an early appointment, feel free to call with questions about things like medications you're currently taking, symptoms that are worrisome, or chronic health conditions that may affect your pregnancy.
If you have a history that might suggest you need to be seen sooner, make that clear. For example, a history of previous pregnancy loss , complications like pain or bleeding, or chronic conditions that you had before pregnancy like diabetes or hypothyroidism call for an appointment. An appointment can also help you get rid of any doubts about the result of your pregnancy and confirm that you are indeed going to have a baby. With take-home pregnancy tests, sometimes you may have doubts about the result—is your result a false positive?
There are a few things to keep in mind as you evaluate your pregnancy test result. Usually, when people wonder about false positives, they are concerned they are seeing an evaporation line. An evaporation line rarely has any color to it.
Evaporation lines are more common with certain brands of pregnancy tests. Most tests will tell you to look after a certain number of minutes, but before another certain number of minutes. For example, the pregnancy test may instruct you to look at the test three minutes after taking it, but not after 10 minutes have passed. Evaporation lines are not an issue with digital pregnancy tests.
Digital tests display results as "Pregnant" or "Not Pregnant. This is one of the advantages of digital tests, though they are usually more expensive. False positive pregnancy tests are possible but rare.
There are some medications and medical conditions that can cause a false positive. This is because hCG is the hormone that is being measured by the pregnancy test. Avoid this problem by waiting at least 10 days after your trigger shot before taking a pregnancy test. If you're having doubts, take another test or visit your doctor.
Pregnancy symptoms and signs are not accurate indicators of pregnancy. Some people never experience morning sickness or other symptoms, but they are just as pregnant as those who do. A lack of pregnancy symptoms doesn't mean you aren't pregnant.
On the flip side, some people may experience cramping, which is usually associated with having a period, which would mean you're not pregnant. It's natural to worry if you get a positive pregnancy test but are having cramps. Know that slight pelvic discomfort during pregnancy is normal. Mild ovarian hyperstimulation OHSS can cause pelvic discomfort and bloat.
OHSS can be monitored or treated by your doctor. If your cramps are intense or severe or accompanied by other worrisome symptoms, contact your doctor. A blood pregnancy test can confirm your pregnancy in your provider's office. If your doctor ordered a qualitative pregnancy test, as opposed to a quantitative pregnancy test, your blood test may come out negative while your at-home test can be positive.
A qualitative pregnancy test only gives a positive or negative result and often requires a higher level of pregnancy hormone than many at-home early pregnancy tests. Quantitative pregnancy tests can sometimes detect pregnancy hormone before an at-home test can. Most fertility doctors will order a quantitative pregnancy test, which gives a measure of how much hCG is circulating.
This is usually followed by another test a few days later to see how quickly the hCG levels are increasing a sign of a healthy pregnancy. It is also possible, if your blood test came back with a very early positive, that you can get a negative test at home a few days later because of an early miscarriage. In this case, your period will probably start soon. There are a range of different emotions that may wash over you as you consider the news and its impact on your life.
Allow yourself to react in whatever way feels natural. Not everyone has a planned pregnancy or is immediately happy with the news of their pregnancy. Don't panic. Sometimes, even if you were planning your pregnancy, it's normal to find yourself second-guessing your plans. If this is an unplanned pregnancy, stay calm as you carefully think about all of the options. These include adoption , abortion , and of course, changing your future life plans to keep and raise your child.
Take some time to let the news sink in while considering what to do. The American Academy of Family Physicians has helpful information on the available choices for an unplanned pregnancy, along with a list of support groups for each option. While you shouldn't have alcoholic beverages during pregnancy, that doesn't mean you should stop having fun.
A glass of sparkling cider is a great way to liven up the night and toast your new bundle of joy. While some people plan a romantic dinner to surprise their partners with the news of the pregnancy, others have bigger parties. How and when you celebrate may depend on many factors. Either way, remember that having fun is a perfectly acceptable part of pregnancy.
By having fun, you're releasing stress and relaxing, which is good for you and the baby. Telling your family and friends about your new family addition is fun and exciting. Some families wait until after 12 weeks, the first ultrasound, or a special date to begin telling everyone, while others begin sharing the news right away. There isn't a right or a wrong way to do it—choose what's best for you.
You will want to know what to expect in your pregnancy week by week. Sign up for an early pregnancy class where you can ask questions and get in-person responses. Both in-person and online resources will give you knowledge to start making the appropriate decisions for you and your baby.
Books are also a great source of knowledge about pregnancy, birth, and the postpartum period. Getting a good night's sleep, eating well, taking a prenatal vitamin, and exercising safely can all help ensure a successful pregnancy, easier labor, and a healthy baby. Listening to your body's signals, whether it be morning sickness or exhaustion, will help you cope more easily with symptoms of pregnancy.
Your doctor can schedule successive pregnancy blood tests to make sure your hormone levels are increasing as they should and that your pregnancy is healthy. Ultrasounds and physical exams can also confirm that all is well with your pregnancy. While a pregnancy test will typically show up with a darker positive line the further along you are, using the darkness of the line on your pregnancy test is not an accurate way of measuring how healthy your pregnancy is.
They are just meant to detect if there is a minimum amount. Whether you're talking to your family or friends, support is a must-have for anyone who is pregnant.
So much will change in your life and you'll have many questions. You will need to surround yourself with people who can help you talk things through. Sometimes that will be your midwife or doctor and other times that will be your friends and family. Consider finding others who are due when you are due to share the ups and downs of pregnancy. These friendships can last a lifetime and are often helpful. After all, it's only nine or 10 months.
While the end of pregnancy seems really far away, it does arrive more quickly than many parents anticipate. The first few days and weeks after a positive pregnancy test may be full of mixed emotions.
There are certain things that you need to start working on to have a healthy pregnancy, like getting started with prenatal care and beginning to take prenatal vitamins, if you haven't already done so. Be gentle with yourself if you feel a bit sensitive about the whole subject. It may take you some time to adjust to the news, and that's normal.
Seek support if you need it! Get diet and wellness tips to help your kids stay healthy and happy. American Academy of Family Physicians. Options for unintended pregnancy.