Sometimes desired, sometimes by surprise, pregnancy is always a radical change in a woman’s routine. Some have symptoms early on, which may be milder – such as cramping and mild swelling of the abdomen – or more intense – such as vomiting and fainting.
The most frequent sign is the delay in menstruation, but there are women with a very irregular cycle who may not notice it or, still, there are those who have other bleeds that are confused with menstruation.
Other signs that may indicate pregnancy are:
- The presence of pink vaginal discharge, odorless and more intense than normal;
- The presence of cramps or mild abdominal pain with swelling of the region;
- Pain or tenderness in the breasts;
- Change in the constitution of the skin (more oily or more dry);
- Tiredness or fatigue;
- Nausea and nausea;
- Sleep disorders;
- Sensitivity to smells, mainly from food;
- Variation of mood.
But, as they are wide-ranging symptoms that will not necessarily occur, their presence (or absence) is not capable of determining pregnancy.
A few years ago, confirming whether these symptoms were caused by a developing baby was much more complicated.
The cost, the time of the result and the need for a medical request hindered the female accessibility to the exam.
Now, women have cheaper options, easy to find, with very fast results and the possibility of detecting pregnancy in the first few weeks or days.
- 1 What is pregnancy test?
- 2 How does fertilization happen?
- 3 The hCG in the body: symptoms of pregnancy
- 4 Types of pregnancy test
- 5 Home pregnancy tests
- 6 How to do the pregnancy blood test?
- 7 How to do the urine test (pharmacy) for pregnancy?
- 8 When to make HCG beta of blood or urine?
- 9 Where to do it?
- 10 Price: what is the value of beta HCG tests?
- 11 How to interpret the results?
- 12 What is a false negative?
- 13 What is the false positive?
- 14 The history of pregnancy tests
- 15 Common questions
- 15.1 Can I take the pregnancy test before my period is late?
- 15.2 Can I get tested if I have had bleeding?
- 15.3 Are pharmacy pregnancy tests safe?
- 15.4 The second risk is erased, what does that mean?
- 15.5 The test was positive, but I am menstruating. Is it a false negative?
- 15.6 Can a high concentration of beta hCG be a sign of twin pregnancy?
- 15.7 Which pregnancy test is most accurate?
- 15.8 Can you take a pregnancy test at night?
- 15.9 How do I know how long I’ve been pregnant?
- 15.10 How many days can I take the blood pregnancy test
- 15.11 How much does the pregnancy blood test cost?
- 15.12 Can ultrasound detect pregnancy?
The pregnancy test is a procedure to check the dosage of the beta hormone hCG (called the pregnancy hormone) and verify or discard the pregnancy.
The hormone is produced by the fetus and passes into the mother’s circulation. As the blood is filtered through the kidneys, a part of this hormone is retained by the organ and eliminated by the urine.
Therefore, tests can use both fluids – blood or urine – to detect pregnancy and there are clinical tests and pharmacy tests for this.
Blood tests, performed in laboratories, tend to be more sensitive, detecting pregnancy more precisely.
But pharmacy tests are generally able to deliver accurate results. In addition, they are a practical and inexpensive resource that can be done at home using a small urine sample.
Both have quick results, but the pharmacy test is able to give the opinion in a few minutes, while the blood test can take about 24 hours, depending on the laboratory.
Manufacturers indicate that urine tests are highly effective in detecting the hormone hCG from the first day of menstrual delay and, especially, after the third week of pregnancy.
However, it is always important to confirm the result through the laboratory exam.
When sperm reach the uterus, the search is for fertilization of the egg, through the penetration of the outer membrane. When one of them is able to rupture the ocular membrane, fertilization is carried out.
It takes about 20 hours after the sperm enters the egg for the zygote to form, which is when the nuclei of the egg and sperm (which carry the DNA of the mother and father, respectively) fuse.
Then, the first of several cell divisions occurs.
However, this process still occurs in the tube and, in order to carry out the pregnancy, the zygote needs to reach the uterus and fix itself on the organ wall.
On average, it takes 7 days for this implantation to take place in the uterine cavity, called nidation , which also involves a small amount of bleeding (often mistaken for menstruation leakage).
What is human chorionic gonadotropin (hCG)?
It is only when the entire implantation process in the uterus occurs that the embryo begins to secrete human chorionic gonadotropin, or Beta hCG.
But, in rare exceptions, hCG can be elevated due to the presence of gestational trophoblastic disease and some types of cancer , such as in the ovaries or testicles – that is, men may also have the hormone altered.
The release of hCG occurs approximately between 10 and 12 days after fertilization, by the trophoblastic cells of the placenta.
The hormonal action stabilizes progesterone and estrogen (female hormones), interrupting menstruation, so that the pregnancy can be maintained.
This is the only hormone unique to the gestational period , so its detection is sufficient to determine pregnancy.
The hCG has a fundamental role in the implantation of the embryo and in the maintenance of pregnancy. As it signals the body to inhibit the next ovulations and maintain the production of adequate progesterone and estrogen, preventing abortion from occurring.
With the presence of progesterone, the blood vessels and capillaries (smaller vessels) of the uterus are more strengthened due to a more fortified lining.
Thus, the organ can support the growth of the fetus without risk to the mother or pregnancy.
In addition, hCG is involved in the early symptoms of pregnancy.
That is, those first nausea, dizziness , increased sensitivity and mood changes are the fault of the hormone that increases considerably until the first 10 or 12 weeks.
This time is equivalent to the first trimester of pregnancy, when the symptoms are usually more pronounced.
From that moment on, the tendency is for the levels to drop gradually until the 20th week and, finally, to stabilize.
The normal elevation of most pregnant women in the first 3 months is so high that hCG levels are doubled every 2 or 3 days.
Most pregnant women have an increase of at least 60% of the value every 2 days.
When pregnancy is suspected and, even so, the tests indicate that the hCG is between 0mIU and 25mIU and the menstrual delay persists, the tests should be repeated between the next 3 and 10 days.
For values between 25mIU and 100mIU it is considered positive or indeterminate, and may vary according to the laboratory. If the exam is found to be indeterminate, the exam must be repeated in at least 3 days.
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With high hormonal production, some changes begin to occur in the body, but these signs are not mandatory requirements for pregnancy to be developing, as each woman will experience the next few months in a very individual way.
You have probably heard of a mother who had all the signs, desires and nausea since the first few weeks, while another one reached the 5th month with almost no stomach and no symptoms.
When they occur, among the most frequent perceptions are:
Discomfort in the abdominal region
Cramps can occur in the early days, accompanied by discomfort and tugging in the uterus and are often attributed to menstruation.
Change in the breasts
Like the belly, the breasts will undergo major adaptations during the gestation period. The breasts can become more sensitive and painful, with swelling and itching. In addition, it is sometimes possible to notice bluish veins in the region and the darkening of the areolas.
Nausea and vomiting
Nausea and vomiting are one of the first and most recurrent signs of pregnancy. The association is so constant that if any woman reports feeling sick (even after having eaten a super heavy lunch), someone will certainly ask about pregnancy, whether as a joke or not.
There are two hypotheses about this symptom in pregnant women. One is that the fetus is initially considered an invader.
It occupies a woman’s internal space and feeds on its nutrients as it develops.
In this sense, the organism does not yet understand exactly the changes that are occurring and, therefore, considers the baby as a threat to the woman’s integrity.
Sickness would be a way to fight and warn the rest of the body that something is wrong.
A second hypothesis is that the mother’s organism is mobilized to protect and strengthen the baby, so nausea would be a protective response, preventing the toxins present in food from affecting the embryo in this still critical period of development.
Dizziness and vertigo
Dizziness is quite common in the first trimester of pregnancy, often associated with low pressure. If the region or season is hot, care must be taken to prevent fainting from occurring.
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There are two methods for confirming pregnancy: the urine test and the blood test. Both can be used, but for an effective medical diagnosis, it is the blood test that counts.
That is, when you go to the doctor – even with dozens of pharmacy tests showing the positive -, blood Beta hCG will be ordered.
Although manufacturers and laboratories indicate that the pharmacy test is quite safe, hCG levels in the urine are lower than those in the blood, so they may not be detected in the initial periods.
Know a little about each method and its effectiveness:
The exam does not require fasting and can be requested by any medical professional or performed privately, without the request. It usually takes less than 24 hours for labs to give their opinion.
There are 2 types of exam: qualitative and quantitative. Both will analyze the presence of the hCG hormone in the blood, but they differ in the way they present the results.
The qualitative pregnancy test will only indicate “positive” or “negative”. It is done through hCG hormonal measurement, but without pointing out the values. Compared to the quantitative test, the result tends to be faster and easier for women to read.
For those who are in a hurry for the result, the quantitative examination may take a little longer, and may take up to 48 hours depending on the laboratory.
The quantitative test can also be used for purposes other than confirmation of pregnancy, such as monitoring gestational trophoblastic disease, ectopic pregnancy (outside the uterus), germ tumors and abortion.
In pregnant women who have higher hCG rates since the beginning, the values rise more slowly.
The quantitative test can assist in indicating the period of pregnancy, but to know more precisely the time of pregnancy, it is important to talk to the doctor.
In general, the results of the hCG rate should be combined with ultrasound to determine the length of pregnancy.
Urine test (pharmacy test)
Pharmacy tests can be purchased without the need for a medical request or indication.
In general, they start at R $ 3 and offer reliable results in 99% of cases, according to the manufacturers. The test is quite quick and the result appears in less than 5 minutes.
Each brand may have a different sensitivity, which will appear on the packaging, and it is worth remembering that the most expensive is not always the most accurate or most sensitive.
While some models with high precision can detect levels of 20mIU / mL of hCG in the urine, the less sensitive models can measure from 50mIU / mL of the hormone.
Even if some manufacturers indicate the ability of the test to identify pregnancy up to 4 days before the menstrual delay, the most suitable is that the method is done from the 1st day of the delay, because before that the chances of a false negative are greater .
If the test is negative, but menstruation is delayed or there are indicative symptoms (such as nausea), the woman should repeat the test after at least 3 days.
There are different presentations of the product – tapes, pens, digital, and liquid – but they all work in an approximate way, identifying hCG in a small urine sample. Understand a little more about each type:
Some tests are done with strips or rods, which may be accompanied by a urine collection cup or not.
The manufacturers of the most popular brands indicate that the product has an accuracy of up to 99.9% and the result appears between 1 and 3 minutes.
The strip is produced with paper, dye and reagent antibodies, coming in sealed plastic or silica packages.
The pen pregnancy test is very similar to the ribbon test, usually with the altered shape, being wider and more anatomical.
Some models come with a urine collection bottle, but like tape ones, they can be placed directly in the pee stream.
The pen presents the result in the same way as the strips, with 1 or 2 streaks, indicating negative or positive, consecutively.
There are digital pregnancy tests that follow the same pattern as the model made with rods or ribbons. The main difference is the digital way to reveal the result, but the reaction is the same, occurring by hCG detection.
Through the urine, the small meter will indicate whether the liquid has high concentrations of hCG.
The main manufacturers indicate that the digital test has an accuracy greater than 99%, with the ability to identify pregnancy up to 4 days before menstrual delay. In addition, the digital version has an easier-to-handle format.
There are brands that offer the quantitative version of the digital test. In this case, if the result is positive, the meter indicates how many weeks ago the conception occurred (1 to 2 weeks, 2 to 3 weeks or more than 3).
Manufacturers indicate an accuracy of up to 92%, in general, when measuring design time.
The model is basically a test tape, but instead of the result appearing in 1 or 2 strips, if it is positive, it will turn blue.
In negative cases, the test may turn red or yellow, depending on the model.
Despite being widely used in other countries, the liquid type is not well known in Brazil because it is not sold here.
Home pregnancy tests
Pharmacy tests are also called home tests. In addition, you may have heard of homemade alternatives to urine testing, but there is no scientific evidence that they are functional or reliable and may even pose health risks .
An easy search on the internet and you will find easy methods to detect pregnancy using products like bleach, vinegar or even cola soft drinks.
In general, they are tactics that were used before scientific advances and remain in popular knowledge.
In the case of bleach, when mixed with urine, it can be harmful to breathing, emitting irritating odors.
The ideal is to use the pharmacy exam which is fast, safe and efficient in most cases. If the result is positive, it is necessary to have a medical consultation where the blood test will be requested.
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For those who have never had a pregnancy test, the information is always facilitating. Check out how it works and how to proceed in each type of exam:
The blood test to detect pregnancy follows the traditional collection procedure, in which a sample will be taken from the vein in the arm, unless it is not possible or feasible to perform the puncture at the site.
You don’t have to be fasting to take the quali or quantitative exam.
In the case of the first, reading the exam is simple, with results such as “positive / reactive” or “negative / non-reactive”.
The quantitative type often needs more care. Some laboratories may recommend that the patient has not used biotin (vitamin B7) in the past 72 hours, or contrast tests in the past 48 hours.
For pharmacy tests, it is recommended to perform them with the first urine of the day.
Although, according to the manufacturers, they can be made with any pee sample throughout the day, it is in the first sample that the chances of false negative are less, as there is no risk that the urine is diluted.
If you have ever had a urine test, you know that the recommendation is to discard the first jet and collect the rest of the pee. Then you can follow the same procedure.
The tests are, for the most part, quite similar in their performance, but it is always necessary to carefully read the instruction leaflet that comes with each product.
Both the tape test and the digital test can, in general, be done with the urine collector or by placing the meter directly on the jet.
Before carrying out, check that the model you purchased can be done in both ways.
In general, to do so, just follow the following steps:
- Open the test (only at the time of use so as not to run the risk of alteration);
- If the test is accompanied by the collecting cup, pee in the container and immerse the tip of the rod indicated in the urine, ensuring that the entire required region is immersed in the liquid. If the cup does not come, you can purchase one separately in pharmacies;
- Wait 10 seconds and remove the meter from the collecting cup, leaving it to rest on a flat surface.
Ideally, the pee should be used in the test right after it is done, however some manufacturers indicate that, after peeing in the collector, you can use it in up to 2 hours if left at room temperature, or in up to 4 hours if kept in refrigerator.
Some tests may show a pink line in the first few seconds, but this is only an indication that the meter is reacting. You should wait between 1 and 3 minutes for the final result.
Directly in the urine stream
If you prefer to dispense with the collector or do not want to purchase one separately, you can perform the test as follows:
- Open the test (only at the time of use so as not to run the risk of alteration);
- Identify the detection tip and place it under the urine stream for 5 seconds (or according to the manufacturer’s recommendation);
- Rest the meter on a flat surface and wait for 1 to 3 minutes, according to the instructions.
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Pharmacy tests show more reliable results if they are taken from the delay of menstruation, because before that, in pregnant women, hCG levels are quite low and often undetectable in the urine test.
Although some laboratories point out the effectiveness of the pharmacy procedure even before the cycle is delayed, doctors suggest the best sensitivity of the blood test, mainly because there are women who do not have the cycle well regulated.
In such cases, you can consider the length of your cycle to be longer. For example, if your period occurs at intervals of 25 to 35 days, consider the delay after the thirty-fifth day of your last period.
In addition, in cases of irregularity, the test can be performed after 20 days of sexual intercourse.
If you are not planning or expecting a pregnancy (and pregnancy tests are already part of your monthly routine), some signs may be indicative for taking the test:
This is usually the first sign noticed by the woman. Those who have a regulated cycle more easily perceive menstrual absence, but those who do not have such a regulated organism may take longer to notice something different.
In any case, delayed menstruation is always an important sign.
Body symptoms and signs
Breast pain, swelling, nausea, cramps and dizziness are some of the symptoms of pregnancy.
If you start to notice changes in mood, changes in appetite, increased body sensitivity (pain) and emotional instability (irritation, euphoria, anxiety or any other emotional signs), it’s time to get tested.
Contraceptive methods, such as condoms and pills, have high protection, but are likely to fail.
Ideally, the pill should always be taken at the same times and that condoms should still be used.
Surveys show that there are risks of up to 1 woman in every 100 who take contraceptives daily and make rigorous use of the method (every day, at the same time, with medical supervision) are at risk of becoming pregnant.
This value rises to 9 for every 100 women who make irregular use (altered schedules, without medical supervision or forget to take the medication at some time).
Therefore, being attentive to the signs is always important, but if you are part of the group that does not make rigorous use of the method (or eventually forgot it in a day), the pregnancy test can be recommended.
The blood test can be ordered by the doctor and done at any clinic, laboratory or hospital that performs blood collections.
In general, the test needs a referral guide if it is performed by health insurance companies, but if you are going to take the private exam, it can be ordered directly at the collection site.
You only need to check the laboratory’s availability and policy to carry out exams without a medical guide.
On average, the beta HCG blood test costs from R $ 40.
Urine tests, on the other hand, can be found in commercial pharmacies and cost from R $ 3, up to R $ 40.
Below, you can find a list of some of the most popular pregnancy tests ordered by average price:
- Pregnancy Test Check : between R $ 2 and R $ 4.
- Verifik Pregnancy Test Strip : between R $ 4 and R $ 5.
- Pregnancy Test Check Pratic : between R $ 6 and R $ 15.
- Pregnancy Test Baby Test : between R $ 9 and R $ 12.
- Grav Test Click Pregnancy Test : between R $ 10 and R $ 15.
- Pregnancy Test Confirme Plus : between R $ 14 and R $ 22.
- Clearblue Digital Pregnancy Test : between R $ 27 and R $ 50.
In Consulta Remédios you will find these and other options. In addition to comparing prices, it is possible to find complete information about each test.
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In general, pregnancy tests are very easy to interpret, whether they are pharmacy tests or blood tests.
Blood test result (value)
The blood tests normally used can detect levels of the hCG hormone of at least 5mUI.
There are more sensitive tests, which can detect from 1mUI per mL of blood, but which are not part of the tests offered by most laboratories.
In qualitative tests, the exam will show positive / reactive or negative / non-reactive, and may be accompanied by the following parameters:
- hCG below 5mIU / mL = negative;
- hCG between 5mIU / mL and 25mIU / mL: undefined result (it is recommended to repeat the exam after 3 days);
- hCG above 25mIU / mL: positive result.
Quantitative: What is the level of hCG to be pregnant?
In the quantitative tests, the results presented are more specific, indicating the gestation time according to the hormonal quantity detected.
Below you can find an estimated average hCG dosage according to your last menstrual period (UPM). That is, to interpret the ideal average value, you need to know when your period last dropped:
- 3 weeks (UPM) : 5 – 50mIU / mL
- 4 weeks (UPM) : 5 – 426mIU / mL
- 5 weeks (UPM) : 18 – 7.340mIU / mL
- 6 semanas (UPM): 1,080 – 56,500mIU/mL
- 7-8 weeks (UPM) : 7.650 – 229,000mIU / mL
- 9-12 semanas (UPM): 25,700 – 288,000mIU/mL
- 13-16 semanas (UPM): 13,300 – 254,000mIU/mL
- 17-24 semanas (UPM): 4,060 – 165,400mIU/ml
- 25-40 semanas (UPM): 3,640 – 117,000mIU/mL
- Mulheres não grávidas: < 5.0mIU/mL
- Mulheres depois da menopausa: 9.5mIU/mL
Mas, lembre-se, os valores são uma média e não funcionam como uma tabela determinante. Isso ocorre porque os níveis de hCG podem começar baixos e demorar um pouco para se elevar, subindo rapidamente após alguns dias.
Resultado do teste de farmácia
Como a ideia do teste é facilitar a obtenção do resultado, o teste é rápido e simples de ser lido. Seja o modelo em tira ou o digital, consulte sempre o folheto informativo, mas no geral os resultados são interpretados da seguinte maneira:
Nos testes de fita, irá aparecer 1 risco para negativo ou 2 riscos para positivo, invariavelmente. Ou seja, 2 riscos, sejam eles paralelos ou em cruz “+” invariavelmente indicam gravidez.
Nos testes digitais, os resultado pode aparecer também com os riscos, igual ao de fita, ou com a informação escrita “positivo/reagente” ou “negativo/não reagente”.
Os testes digitais podem ser comprados na versão quantitativa também, que mostra o resultado estimado do tempo de gestação.
Em geral, esse tipo mostra o processamento e indicam enquanto a leitura está sendo feita e os resultados possíveis são:
- Not pregnant ;
- Pregnant 1-2 : conception occurred approximately 1 or 2 weeks ago;
- Pregnant 2-3 : conception occurred between 2 and 3 weeks;
- Pregnant 3+ : conception occurred more than 3 weeks ago.
Manufacturers point out that the digital test week indicator has an accuracy of approximately 92% in detecting conception time.
In general, incorrect results are uncommon, but false negatives can occur if the test is done in the early days of pregnancy, when there has not yet been enough time for hormone production to begin.
Blood tests are able to detect much lower concentrations of hCG compared to urine tests, that is, they are able to point out the positive result in the first days.
Therefore, for those who want to use the pharmacy method, it is necessary to wait for the first day of menstrual delay, reducing the risks of false negative.
For medical validation, blood tests are always used.
In addition to more accurate detection, blood hCG is usually identifiable between the 8th and 13th day after conception (which is roughly 1 to 6 days before menstrual delay occurs).
There are few causes that lead to a false negative of the blood test. In general, it was performed very early, with no time for hCG rates to rise.
One of the factors that causes this mistake is the irregular menstrual cycle, because the woman thinks she should be menstruating and undergoes the exam.
But the correct period to start menstruation has not yet occurred.
In pharmacy tests, the false negative can still occur if the pee used is too diluted, so the ideal is to do the test with the first urine of the day.
The use of diuretics or promethazine (antihistamine) can cause a false negative in the pharmacy test, as these substances contribute to the dilution of urine.
Factors such as the use of contraceptives, alcohol, infections, use of antibiotics are not able to interfere with the results.
Performing the test incorrectly can cause a false positive. For those who are going to do the type of pharmacy, it is always necessary to read the instructions and be attentive and careful to the realization.
The amount of urine, the cleaning and sterilization of the collection container and the expiration date of the test can interfere with the results.
If the test was performed correctly, with all the care taken, there are still other factors capable of determining how many lines will appear on the meter.
Reproductive treatments (to assist in the maturation of the follicle or implantation of the embryo, for example) and testing in recent periods of childbirth or an abortion are the most common causes of false positives.
This is because to assist in reproduction, treatments based on the hormone hCG are used and, after delivery, the levels still take a while to drop, just like in cases of abortion.
In addition, when the egg is fertilized, but it was not able to be implanted in the uterus, there may be a hormonal elevation, without actually continuing the pregnancy.
It is estimated that up to 15% of fertilizations fail to develop and implant in the uterus.
Some medications can cause a false positive in the urine test, including:
- HCG hormone, used in the treatment for reproduction;
- Tranquilizers, such as diazepam and azapironas;
- Antipsychotics, such as chlorpromazine , clozapine , triflupromazine and thioridazine ;
- Anticonvulsants and antiepileptics, such as phenobarbital ;
- Medicines for Parkinson’s disease, such as phenylalanine, tyrosine dopamine, bromocriptine and anticholinergics, such as benzatropine and scopolamine;
- Diuretics, such as furosemide , spironolactone , thiazides and osmotic diuretics, such as mannitol and glucose;
- Antihistamines, such as Promethazine .
Diseases and changes in the body, such as hepatitis, cysts, tumors in the ovary, urinary infections, as well as rare diseases, including lupus , Iga deficiency, hydatidiform mole and some types of melanomas and carcinomas may still be responsible for the false positive.
Women in menopause or who are close to the stage may have elevated hCG.
This is because of hormone production by the pituitary gland, a brain gland. In these cases, the results show results generally just above 25mIU.
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Knowing whether there is a baby on the way or not is somewhat relevant information. For this reason, it is not new that tactics and methods of confirming suspicions are being sought.
Since the time of the Egyptians, there have been reports of techniques used for the detection of pregnancy, which have been explored, developed and changed over the years until we reach the current high-precision exams.
In fact, it is not only the sensitivity and effectiveness of the test that became much more accurate, but also the versatility – you can find out if you are pregnant by peeing in the bathroom of your home and know the result in less than 5 minutes.
But it was not all that simple and many of the techniques used in the past were somewhat bizarre.
In Egypt, to find out if a new child would soon come into the family, grains of barley and wheat were placed in cloth bags and the woman’s pee was mixed. If the grains germinated, the result was positive.
But Egyptian ingenuity was not limited to positive or negative results, as it was believed that one could even know the sex of the child.
If it were the barley grains that germinated, it would be a boy. If they were wheat, girl.
After the discovery of the hormone hCG, scientists and researchers began to adopt animals for the pregnancy test.
In approximately 1928, the procedure consisted of injecting the woman’s urine into a rat and evaluating the animal.
If the woman were pregnant, the rat would start estrus because of the hormonal presence.
However, it was only possible to identify the beginning of the heat of the rat by checking if there was an increase in the ovaries through a dissection after 5 days, that is, killing the animal.
Some time later, the mice were replaced by rabbits.
The test consisted of injecting the woman’s urine into the pet’s ears. The researchers observed the rabbit and if there was a metabolic change, the result of the pregnancy was positive.
Although it is possible to keep the animals alive, it was necessary to perform surgical interventions, which made the procedure quite costly (both in terms of price and time spent).
That is, the animal needed to be euthanized after the pregnancy test.
According to information from the University of California, frogs of the Xenopus genus were used as pregnancy tests in hospitals in the 1940s and 1950s, as they were quite sensitive to hCG.
The animals then began to be used to detect pregnancy.
The frog test consisted of injecting a pregnant woman’s urine into a frog. As the pregnant woman’s pee is rich in hCG, the amphibian would be stimulated to ovulate between 8 and 10 hours.
Although not all animals were sacrificed, the number of deaths was still high.
If we were around 1960, it would be much more complex to detect a pregnancy. In general, the exams were done in the laboratory and were still time-consuming and laborious.
The first home pregnancy test was manufactured in the late 1960s by Margaret Crane, an American publicist who did not even have a background in chemistry or biology.
Margaret visited the laboratories of Organon Pharmaceuticals, a cosmetic company, to draw the sketches of some products.
However, what she did was to revolutionize the way women followed their lives, as she was responsible for reproducing pregnancy tests at home.
Until that time, detecting a pregnancy could only be done with the help of a laboratory and specialized chemists.
In 2015, the prototype elaborated by Margaret was auctioned for US $ 12 thousand (something around R $ 45 thousand in the current currency), acquired by the Museum of the History of America, in Washington.
Can I take the pregnancy test before my period is late?
It can, but the results run the risk of not being so accurate, especially in the pharmacy exam.
If the method chosen is blood, due to the high sensitivity, it is possible to identify hCG approximately 6 days before the menstrual delay is noticed.
Some home testing labs indicate that the sensor is capable of capturing even the small hormonal concentrations that are expected before menstruation is delayed. However, most false negatives are due to the exam being performed too early.
Can I get tested if I have had bleeding?
Yes. It is worth remembering that not all bleeding is menstruation. It can be caused by the nesting process (implantation of the egg in the uterus) or even by a recent abortion. In all cases, the pregnancy test can be performed without the bleeding altering the result.
Are pharmacy pregnancy tests safe?
Pharmacy tests are a good option for detecting pregnancy. Currently, manufacturers develop very accurate and easy-to-use techniques provided they are used at the right time.
The concentrations of hCG in the urine may take a long time to rise, so if the test is done too early, the result may not be as accurate.
It is also important to remember that tests sold in pharmacies are useful for the woman to have a quick and accessible resource to check for the presence of pregnancy. However, it is not a substitute for laboratory testing or medical consultation.
As with any exam, the pregnancy test can suffer from interference as well. In fact, even a blood test can show a false negative, so medical follow-up is essential.
The second risk is erased, what does that mean?
Regardless of color or appearance, if there are 2 risks in the pharmacy test, the result is positive. Sometimes, the low hormonal concentration can interfere with the formation of the symbol, but this does not change the indicative of pregnancy.
In cases of doubt or insecurity, repeat the test or perform a blood test.
The test was positive, but I am menstruating. Is it a false negative?
There is a very common mistake when it comes to pregnancy and menstruation, as it is not possible for them to occur together. For pregnancy to develop, there is a hormonal release that inhibits menstrual bleeding.
You may even know women who kept bleeding while they were pregnant, but the truth is that it is bleeding from a source other than menstrual. Between them:
- Implantation bleeding (small amount of fluid that occurs when the embryo is implanted in the endometrium);
- Bleeding after gynecological examinations or sexual intercourse: it is possible that the inner walls of the vagina and cervix are more sensitive and, therefore, hurt themselves more easily;
- Gynecological infections: herpes, candidiasis, bacterial vaginosis and chlamydia, in general, do not trigger bleeding, but they can make the wall of the vaginal region more irritated and sensitive, favoring injuries. In addition, bleeding can be a sign of gonorrhea and should be investigated.
Other factors may be more serious, for example the placenta previa (up to 80% of patients with placenta previa bleeding without pain) or premature detachment of the placenta (bleeding also affects 80% of patients), in which the risks to the mother and to the baby are bigger.
Can a high concentration of beta hCG be a sign of twin pregnancy?
The high dosage of hCG can be an indication that you are pregnant with twins, but only an ultrasound is able to confirm the result, as the amount of hormones varies greatly for each woman.
Generally, the symptoms of early pregnancy are strongest in mothers of twins due to the high hormonal concentration, so it is the hCG that causes the initial symptoms.
However, if the exam is a pharmacy tape, having 2 well-marked lines (very strong and clear) cannot be considered an indication of twin pregnancy.
Which pregnancy test is most accurate?
Although the manufacturers point out that the pharmacy tests are extremely sensitive, with a degree of accuracy that can reach 99%, the blood test is even more suitable to confirm pregnancy.
In matters of branding for pharmacy tests, it is only necessary to pay attention to the validity and certification of ANVISA. The most expensive product does not always represent the best quality or the best cost benefit.
Can you take a pregnancy test at night?
Yea! Some pharmacy tests indicate that the best urine to use is the first one, upon waking up. Because it is more concentrated, in general, it is more suitable. However, the test can be ugly at any time and maintains the high sensitivity rate.
How do I know how long I’ve been pregnant?
In a regular cycle of 28 days, ovulation occurs on the 14th day after the start of menstruation, and may occur 3 days before or after that date.
Sperm can survive for up to 72 hours inside a woman’s body.
After ovulation, fertilization has up to 24 hours to occur and, between 5 and 7 days, the egg migrates to the wall of the uterus (which is in the endometrium), configuring the nesting process.
Since it is very difficult to determine precisely the day on which fertilization occurred, doctors count the gestation from the menstrual delay.
In general, the embryo is about 14 days younger than the day of menstrual delay.
Therefore, women who have a well-regulated cycle are able to estimate more easily when they started their pregnancy.
If menstruation is extremely unregulated, you should wait for an ultrasound exam to confirm the weeks of gestation.
How many days can I take the blood pregnancy test
The blood test, in general, is already able to detect pregnancy in the first week, even before menstruation is delayed. However, some women may initially have a low hormone production of beta HCG.
Thus, the most indicated is that the exams are done or repeated from the 1st day of the menstrual delay.
How much does the pregnancy blood test cost?
It depends on the laboratory. On average, the HCG beta blood test can be found from R $ 40.
It is also possible that the exam is requested in the public health system (SUS), according to the medical request.
Can ultrasound detect pregnancy?
Ultrasound is an image exam that, in general, is used to monitor pregnancy. This is because, for most women, he is only able to indicate the presence of the baby after the 5th or 6th week of gestation.
During this period the doctor can already identify the gestational sac. But it is important to remember that in the 5th week the baby is still an embryo with only about 6mm.
For those who want to know the sex of the baby, it is necessary to wait at least until the 13th week, being that it is usually only on the 15th that the doctor can affirm the sex.
So, yes, ultrasound can detect pregnancy, but it is usually used to accompany it and not to confirm it.
With high sensitivity and a very fast result, pregnancy tests can be done at home, with the urine test, or in laboratories, with blood tests.
Despite the fact that doctors check the pregnancy before the laboratory exam, those sold in pharmacies can confirm or dismiss the suspicions of pregnancy, in addition to offering a low cost of accomplishment.
As soon as there is a suspicion of pregnancy, the examination must be performed so that the necessary care, in positive results, can be initiated.
The tests sold in pharmacies are a quick and considerably safe option, but care must be taken during the procedure, following the procedures indicated by the manufacturer and respecting the correct periods (preferably after menstrual delay).
For the blood test, the results are reliable and the possibilities of false results are uncommon, except in cases where there is organ dysfunction or the use of some medications. Therefore, it is always necessary to seek specialized guidance and inform the doctor about treatments and symptoms.
And if the result is positive, find in the Healthy Minute care and wellness tips focused on pregnancy!