Can pregnancy tests be trusted? Can a pregnancy test be wrong? Types of tests, the probability of error, how to conduct the test correctly in order to get a reliable result How reliable are pregnancy tests

You know, those who believe that a guide in an unfamiliar area should be a person who knows it thoroughly are right. Whatever we say, even our own experience is often only a subjective experience.

Here, for example, is how to determine for sure after what time a pregnancy test will show an accurate result.

Reliability of pregnancy tests according to doctors

So, doctors conducted a small online survey and found out that in hundreds of cases, when determining pregnancy, women received false results. And most often due to the fact that they ignored advice on the optimal ten-day period from the date of fertilization of the egg. Before this time, according to doctors, it is unrealistic to get a reliable result.

Even according to urine tests, doctors cannot accurately state pregnancy earlier than 14-16 days after ovulation. An exception to the general rule can only be those women with a shortened cycle, the second phase of which is less than two weeks.

Do pregnancy tests always show the truth?

Frankly, at first my knowledge of the principle of the test strips was limited only to the instructions on the product itself. And in the same place on the package, as a rule, it is written that with their help you can find out if you are pregnant already on the first day. I do not remember exactly, it seems even from a few hours.

And, not knowing the other features of the hCG test, I followed exactly these instructions. I confess that in my life I had to use them more than once, and I knew by heart what the strip looks like when there is no talk of pregnancy, and how - when the suspicions were justified.

I used the tests on the second or third day and within a week from the alleged moment of conception. And even if as a result two strips were not clearly visible, during pregnancy he behaved differently, and the location of the second strip became cloudy. And this diagnosis, as a rule, was justified.

But those who say that we are all individual are right. And what works for some may fail for others. When I read the reviews of different women, I was convinced of this again.

Therefore, I agree that specialists are much better versed in everything related to medical supplies. However, doctors know much more about the principles of the tests.

So, they claim that it is possible to say for sure from the test results whether you are pregnant. You can only find out that you are pregnant from the results of such a test only from 14-15 days after ovulation. This is not written on the packaging for the tests, but doctors insist that this is so.

Perhaps it is worth saying that this method of diagnosing pregnancy is not fully justified with an irregular cycle. And any menstrual disorders increase the likelihood that there will be problems with conception. Then you just need to consult a doctor, and possibly a treatment that will bring the hormonal background back to normal. And again, not the last role is played in this sense by changing one's habits - lifestyle, nutrition, physical activity.

It is good if the pregnancy is desired and timely. But if pregnancy is not desirable for some reason, you need to find out about it earlier. And in time, as doctors say, it is also desirable up to two weeks.

So what, do not believe the authors of instructions for pharmacy tests? At the very least, for a final and reliable conclusion regarding pregnancy, you need to wait at least ten days. Or go to your gynecologist. Often, from the very first days, by changing the color of the uterus and vagina, and softening the uterus, the doctor will be able to talk about pregnancy.

Anonymous
Time: 23:55 The date: 17/06/03

Tell me, how reliable are the tests (such, in the form of a litmus test - you put it in a jar of urine, one stripe - pregnant, two - not)??
And then here I had a delay of only 2 days, but there is reason to worry about an unplanned pregnancy. I'm taking a test and I'm not pregnant. And menstruation does not begin (I will say, there are delays, but not often). What to do?!?! How to know for sure? Maybe for an ultrasound. So that it won't be too late!

Time: 01:57 The date: 18/06/03

For two weeks now and a couple of days my friend had a delay, I was already preparing to become a dad, but they went today)))
Here's what I found out in two weeks. Yes, tests lie.
They don't show in a day.
Really shows only ultrasound (for sure, that is).
Two days is bullshit. The cycle goes astray from nerves, experiences. And also from physical stress.
If you have had sex without rubber bands, then the chances are high (I never do this, which I advise you).
If you are sure that you could not fly, then wait ...

Time: 02:14 The date: 18/06/03

The test will actually show in 2 weeks. It is better to go and donate blood - in any LCD.

Time: 04:18 The date: 18/06/03

The tests do not lie, but simply the amount of the hormone may still not be enough for such a period. You can try tests from different companies. False positive readings are quite rare, but the test may not show for a long time. But if there is at least a weak strip, IMHO there is a pregnancy. On ultrasound, too, a fetal egg may not yet be seen, so it is best to donate blood to the level of hCG.

Time: 07:35 The date: 18/06/03

uzi will not help, it is better to donate blood. If in a paid clinic, then the result is ready in an hour

Time: 08:45 The date: 18/06/03

Or maybe you got it wrong? Two stripes is just a pregnancy, but one is not.
Ultrasound in such a short period of time very rarely shows. It depends on the device, and even on the uzist.
It is best to donate blood for hCG. It is guaranteed that pregnancy will already be determined at this time.

Time: 08:49 The date: 18/06/03

And my test showed that I was pregnant, while the ultrasound told me that there was nothing. But the test is not in the form of a cardboard box, but more expensive, in a plastic case. And when I did a second ultrasound a week later, the pregnancy was confirmed!

Time: 09:50 The date: 18/06/03

in general, the tests are quite reliable, but it’s better not to be greedy and buy more expensive. And if there is any doubt, then the blood should be donated for hCG

Time: 10:36 The date: 18/06/03

Quite reliable. If in doubt donate blood, there will be no questions.

Time: 10:53 The date: 18/06/03

It may be that during pregnancy it will show its absence. But with two stripes, it's always definitely pregnancy.
Depends on the sensitivity of the test.
If the test is good, and your hormonal levels were normal, then most likely two days after the delay, the test would have shown.
I strongly advise you, rather than worry, go to the doctor - a medical test is much more reliable.

AT.
Time: 12:31 The date: 18/06/03

My test showed on the 4th day of delay. An ultrasound won't show anything. The most reliable blood for hCG.

Time: 16:15 The date: 18/06/03

You need to donate blood for hCG - this is already 100% certainty. Ultrasound will not show anything at such a period, at least from the 10th day of delay ...
My test did not show, although there was CG 151 in the blood, and after 2 days it only gave out 2 bands, when it was 530 in the blood ... Although it had a sensitivity of 25 units, i.e. theoretically should have been rinsed.

Valerie and little wonder girl 30 weeks

Time: 23:04 The date: 18/06/03

How many stripes do you have, one or two?
If there is only one band, then there is nothing to worry about, and if there are two, donate blood for HCG

Question hostess
Time: 00:05 The date: 19/06/03

I did the test twice (the second in 2 days). There was only one stripe.
And about my trouble. THIS happened somewhere on the tenth day of the menstrual cycle. So maybe the egg did not have time to ripen by that time?
And on what day of the delay will the ultrasound show for sure?

Time: 08:47 The date: 19/06/03

Do not wait for the ultrasound to show, they tell you to donate blood for hCG! This is a more reliable way to determine pregnancy at such a short time!
And by the 10th day, the egg might not have matured, especially if your cycle is more than 25 days, but the spermatozoa live inside for up to 5 days, so conception is theoretically possible.

Time: 10:18 The date: 19/06/03

It showed me that she was pregnant - but it turned out that she was not ... so sometimes they are not very reliable ... though I then immediately did other tests - but they were all negative!

Time: 17:48 The date: 19/06/03

Pregnancy - 2 strips, not 1.

Question hostess
Time: 23:57 The date: 19/06/03

All two times there was one stripe, and at the beginning I just made a reservation: one stripe - not pregnant, you noticed everything right.

Time: 10:09 The date: 23/06/03

About the tenth day of the cycle. It all depends on the length of the menstrual cycle itself. And do you correctly define its beginning? Let's count together, I myself was in a similar situation)

Time: 11:30 The date: 23/06/03

You may just have delayed ovulation.

But for many of my friends, the test showed pregnancy only at 6-7 weeks of pregnancy .. so if the delay is more than a week .. then my advice is to go to the doctor

Time: 15:22 The date: 23/06/03

Yes Yes. The question "is the egg ripe or not ripe on the tenth day?" depends on the length of the cycle.
By the way, how regular is sexual life, can the cycle go astray from "interruptions"? Although, I'm not sure, it's more likely a psychological factor.

Time: 22:39 The date: 23/06/03

No. I think it's not about how regular sex life is. Rather, it all depends on the change of partners. For example, when changing a partner, I ALWAYS have a delay. And how are you?

Time: 09:41 The date: 24/06/03

Pregnancy tests lie. During the first two weeks of my pregnancy, the test was negative. And the inner sensation was like before menstruation. And descended or went to the gynecologist - pregnancy was found out So my council to you - do not trust tests. Donate blood - 100% guaranteed.

Time: 11:55 The date: 24/06/03

By the way, a blood test is more accurate .. and it can be done in the early stages, when the tests still show nothing

Time: 18:18 The date: 24/06/03

My test did not show an existing pregnancy after 3 weeks of delay. Here! Just such a hormonal background that pregnancy is not determined ... Since then, I have not used tests.

Time: 00:19 The date: 26/06/03

Reliable. You just need to wait for a certain level of hormones, for whom this happens immediately, then the test shows pregnancy at an early stage, and for someone later - then on the 2nd day of the delay it may not show.

Time: 08:18 The date: 29/06/03

Ultrasound will not show anything right away, after 4-5 weeks of pregnancy only.

A few days of delay in menstruation - and the question of pregnancy arises in the head of a woman. Where to go with him? For an examination by a gynecologist or still trust a home pregnancy test? Of course, running to the pharmacy yourself or sending your loved one there is more convenient and faster. But will two stripes always give you a reliable answer? Or can they still cheat?

You want to trust pregnancy tests and succeed until one day they lead you on the wrong track. To find out that you are still pregnant when the doubt is completely dispelled by testing, or vice versa, to be disappointed with the onset of early menstruation, you see, the surprise is not a pleasant one.

Why do some tests give an accurate result in the first days of pregnancy, while others do not work? The reasons may be different. For example, the test was carried out incorrectly or too early, spoiled due to the expiration date or improper storage.

A pregnancy test will not detect if a woman takes diuretics, has a kidney or cardiovascular disease that affects the excretion of the hormone in the urine. Will not determine testing and . Therefore, if you have a premonition of imminent motherhood, consult a doctor for a more serious examination. Do not wait for your period, take blood or urine tests. They are more reliable and able to determine pregnancy a week after fertilization.

Remember that hormonal changes in the body make themselves felt no earlier than two weeks after conception. And the effect of home pregnancy tests is based precisely on the determination of the hormone chorionic gonadotropin. It begins to be produced in the female body after fertilization. Sometimes, but this is extremely rare, human chorionic gonadotropin is produced by the tumor. Then the woman will also get a positive test result. It can cloud the situation and taking hormonal preparations containing hCG. But other drugs do not distort the results. The presence of alcohol or drugs in the body also affects the reliability.

Today, with the mass production of pregnancy tests, some of them may be of poor quality. Until recently, doctors confidently recommended such testing. But now they prefer a medical examination of a woman with the help of ultrasound.

To protect yourself from false indicators, you can use several tests from different manufacturers at once. Plus, pay attention to your body's messages. The indicators of pregnancy primarily include a delay in menstruation, a slight increase in the breast and its aching, as well as an increase in rectal temperature of more than 37 degrees (you need to measure it in the anus in the morning while staying in bed), and increased urination. Also, the signal will be morning sickness and vomiting, irritability, a tendency to fatigue, a change in appetite, a desire to taste salty or sour.

But even these signs cannot give a 100% guarantee of pregnancy. Since most of them are present before the onset of menstruation or appear with a psychological mood for pregnancy.

Also, a delay in menstruation can be caused by stress, moving, illness, medication, travel, dieting with a sharp change in weight, physical activity.

And yet, if you don’t want to give up taking a pregnancy test at home, as it is relatively cheap, fast, convenient and, importantly, anonymous, you need to do it right.

First, wait for the delay, don't rush. When choosing a test in a pharmacy, pay attention to the release date. Don't be confused by the variety of brands, as the principle of operation of all tests is the same. To enhance the result, the night before, do not drink a lot of fluids and do not take diuretics.

Read carefully. If you still have questions, ask for advice from a consultant on a toll-free number, which is most often indicated on the package.

For testing, take only morning urine. Dip the strip into it to the level and for the time indicated on the package. If you carefully follow all the instructions and instructions for the test, then it is guaranteed by 97% -99%.

Whatever the result of the test, remember that a child is a great gift, and pregnancy is the greatest miracle on earth!

Specially for - Maria Bilykovskaya

Determining pregnancy is not difficult, but with the advent of home pregnancy tests, it has become much easier to do. One of their main advantages is that the “interesting position” can be determined already in the early stages, a few weeks after conception. So, if a girl decides to have an abortion, then in the early stages it will be done with minimal negative consequences for reproductive health.

How the tester is arranged and works

The pregnancy test is a special strip. The principle of its operation is simple: when human chorionic gonadotropin is in a biological fluid (urine or blood), the test strip instantly reacts with a color change, which is manifested by two stripes - the test is positive. In this case, it is likely that the girl is pregnant. In the absence of a hormone, there will be no changes.

Important! For carrying out, they take the morning portion of urine, since the urine accumulated during the night is more concentrated. In this case, a positive result will be the most reliable.

What is human chorionic gonadotropin

Human chorionic gonadotropin or hCG is a special hormone that is produced in the body only by pregnant women. It is synthesized by the trophoblast and placenta after conception, therefore, in non-pregnant women, hCG cannot be synthesized by definition.

HCG begins to be released into the blood after conception, from the moment the ovum is implanted into the wall of the uterus. From this point on, the concentration of the hormone in the blood increases. The highest level of hCG is determined in the blood and urine by the end of the 3rd month of pregnancy, then its concentration decreases.

Important! It must be remembered that for at least a month after the birth, hCG is determined in the biological fluids of a woman, which gives a false positive result of a pregnancy test.

The main function of human chorionic gonadotropin is to maintain the life and functioning of the corpus luteum. This is important for maintaining the implanted fetal egg in the uterus and preventing its detachment, since the corpus luteum immediately after conception produces the main hormone that maintains pregnancy - progesterone. With a decrease in the concentration of this substance in the blood, there is a high risk of spontaneous interruption.

When a test is correct

After conception, the test will be positive only when a certain concentration of the hormone is reached in the blood or urine, to which the test strip you have chosen is sensitive. In the first days of implantation and another 1 week after conception, it is useless to conduct a study, since it will not be informative.

How to use the tester

Today, a wide variety of pregnancy tests are available. Their mechanism of action is the same, only the method of application differs. To avoid mistakes, please read the user manual before using. Below we give a description of several of the most common types of tests.

test strips

These are the first representatives of express pregnancy tests that appeared on the market back in the 20th century. They are popular even today. They are distinguished by a low price, moreover, most women know well how to use them. 2-3 weeks after the expected conception date, morning urine is collected in a separate container and the test strip is lowered there for at least 10 seconds. After that, the result is expected within a few minutes. If the second line does not appear, the result is negative. When the second strip appears, the result is regarded as positive, most likely, pregnancy has occurred.

tablets

Almost no different from previous tests, with the exception that the strips are placed in a plastic frame. They do not need to be lowered into a container with urine, as they have a special “window” where 1 drop of biological fluid is dripped (a pipette is included in the kit). The timing is the same: 2-3 weeks after the expected date of conception. Positive and negative results are evaluated according to the same principle.

Inkjet Methods

They are one of the easiest to use, and at the same time highly sensitive to hCG in both blood and urine. For their use, urine does not need to be collected in a jar. The sensitive part of the test strip is simply placed under the stream during urination and the result is evaluated. The peculiarity of their use: they use not only morning, but also evening urine. The sensitivity of the tests is so great that it can determine the presence of hCG even before the onset of the expected menstruation, which means that it will be positive already 1-2 weeks after conception.

Electronic tests

Electronic tests are the last word of advanced science in the Russian market. The sensitive part is lowered into a container with a biological fluid or placed under a stream during urination. With a positive result, a plus will appear in the “window”, which will speak in favor of pregnancy. Negative - minus.

Important! Even if the paired strip appeared indistinctly or dimly, the presence of pregnancy should not be ruled out. Most likely, the desired concentration of hCG in the blood and urine has not yet reached the threshold value. Test again in a couple of days. The appearance of a clear, bright strip indicates a positive result - you are pregnant.

Which method is the most reliable

The most reliable and reliable method is an express blood test from a vein for hormone levels. Here, hCG appears first of all, and only then in the urine. When choosing other tests, be guided by your preferences, as you prefer. If it is more convenient to use inkjet tests, buy them. If you do not want to fork out for a test and it will be more convenient for you to collect urine and lower the tester there, purchase the most common test strips.

Error results: is it possible and when

False positive two strips are detected in the following cases:

• Previous abortions and miscarriages within a month.
• When taking hormonal contraceptives containing this substance.
• With some malignant neoplasms.

Useful video: How a pregnancy tester works

Positive test after abortion: what to do

After medical termination of pregnancy, chorionic gonadotropin decreases in the blood gradually, so after an abortion, the test will be positive for at least 2 more days. If two strips came out 2 days after the termination of pregnancy, do not panic. Buy another test and do a follow-up test 2-4 days after the first one. In case of a positive result in the control test, immediately inform the gynecologist about this in order to conduct a complete diagnosis of your condition.

Home pregnancy testing has been possible since 1971. It was one of the most useful and convenient inventions, according to women (and many men too). Of course, the first systems for testing were not distinguished by an extremely high degree of ease of use and highly accurate results. But over the years, the tests have gone through several stages of improvement, and today with their help we can get the result within a few seconds, being anywhere. But how can he be trusted?

Can a pregnancy test be wrong and how often does it happen? Let's discuss.

Pregnancy Tests: Reliability Percentage

The invention of test strips was a real breakthrough in medicine. But over time, the wave of enthusiasm faded slightly. No, the test systems more than justified themselves, only doubts began to arise about the reliability declared by their manufacturers. Increasingly, women began to complain about receiving false results, and gradually the percentage of reliability of pregnancy tests from the 99% declared in the instructions began to decline modestly: 97%, 96%, 95%.

Attempts to evaluate the reliability of the results obtained in the process of home testing have been repeatedly undertaken by various research organizations. But in reality, it turned out to be difficult to implement this idea due to the influence of a large number of objective and subjective factors on the final result of testing.

In general, the researchers agreed that the accuracy of modern tests is quite high, but it is somewhat lower than stated in the instructions. According to some reports, approximately 16% of them are able to determine pregnancy on the first day of delay, but already on the 3rd day of delay in menstruation, the vast majority of pharmacy tests will cope with the task.

Meanwhile, firstly, even such a reliability of the result is very high, and secondly, most often not the test itself is “guilty” of obtaining false data, but other circumstances.

Can a pregnancy test lie?

Whatever diagnostic method is discussed, the probability of error always exists! And even ultrasound can be wrong. It is not uncommon for pregnancy tests to show false negative or false positive results, with the former being much more common.

There are many reasons why a test might “lie”:

1. Low product quality. This includes violations not only in the production of such funds, but also in their storage. If the test is expired, stored in unsuitable conditions for this, or was damaged during operation (foreign substances got into the reagent or urine), the probability of an unreliable result increases.
2. Violation of the rules of use. Even the cheapest strips contain step-by-step instructions for the correct testing, and for products from different manufacturers, it may have some differences. Therefore, before starting the manipulation, you need to carefully study the instructions: which end to lower the strip into the urine, to what level, how long to keep, when you can read the results.
3. Testing too early. Admittedly, this is one of the most common reasons why girls who are already pregnant get a negative result. The explanation is very simple: the test is able to determine pregnancy only when the amount of a special hCG hormone (produced by a fertilized egg) in a woman’s body rises to a certain level. On average, this happens 15 days after conception, and therefore very often a test carried out already on the first day of the delay shows a reliable positive result. Meanwhile, it is never known for sure on which day of the cycle the conception took place (ovulation may be shifted, spermatozoa have different activities), how quickly this particular fetal egg develops and when exactly it is implanted in the uterus and begins to produce hCG.
4. "Bad" urine. The hCG hormone is excreted along with urine, and therefore the more concentrated it is, the more reliable the result will be. For this reason, it is recommended to test in the morning with the first portion of urine: the reliability of the test in the evening is markedly reduced, especially in the very early stages. Diuretic foods and drinks taken the day before can also dilute urine. In addition, hCG in the urine may appear as a result of taking medications containing it, and as a result, a false positive test.
5. Hormonal tumors. There are such formations that can produce the hormone hCG in the body of a woman, which has nothing to do with pregnancy. If the result was positive, but there are absolutely no reasons to suspect pregnancy, then it is better to be examined by a gynecologist to exclude the presence of such neoplasms.
6. Diseases of the genitourinary tract and cardiovascular system. Since hCG is excreted from the body by the kidneys, disturbances in the functioning of these organs can cause inaccurate data. However, this does not mean at all that if a woman has polycystic ovaries, cystitis or pyelonephritis, then the test will not show pregnancy. It's just a matter of existing probability.
7. Pathological pregnancy: frozen, ectopic, delayed development of the fetal egg, threatened miscarriage. In all these cases, the production of hCG by the chorion may be insufficient, so the test will not respond to an increase in the concentration of this hormone in the urine.

Please note that no other diseases and conditions, whether it is diabetes, viral diseases, alcohol and drugs, menopause, etc., do not affect the results. The reliability of pregnancy tests while breastfeeding and taking OCs is just as high if tested correctly. But any of these factors, including diet, stress, or a change in the climate zone, can affect the period of ovulation and the length of the cycle, that is, lead to its failure, and in this case, the test may show the onset of pregnancy later.

Reliability of pregnancy tests with soda, with iodine

Finally, I would like to say a few words about the tests themselves. They are different: both in cost and in the way they are carried out. The most modern (and by default - reliable) are the test systems of the latest generation: inkjet and digital. Such devices cost an order of magnitude more expensive than conventional strips, but they are more convenient to use and less likely to make mistakes.

Nevertheless, the simplest test strips available to any woman are able to cope with the task assigned to them no worse than expensive analogues. After all, the principle of operation of absolutely all pharmacy tests designed to determine pregnancy at home is the same. Each test system (from the primitive to the most advanced) contains a reactive substance that can react with hCG, displaying the result on the screen or on the strip. This is how we learn about pregnancy. But this reaction occurs only if the concentration of hCG in the test urine is high enough. The smaller the amount of the hormone the test is able to “respond to”, the more sensitive it is, and the sooner it is able to show a positive result. So, the most common tests show the second band already at a concentration of hCG in the urine of 25 Mme / ml (this threshold is indicated on the test packaging). The sensitivity of the test system, which is 10 Mme / ml, indicates that the reliability of such a pregnancy test will be high even before the delay of menstruation.

Despite this, gynecologists recommend not to force events and, in order to avoid receiving false data, test no earlier than the 3rd day after the delay in menstruation: the later, the more reliable it will be (the most accurate data can be obtained a week after the delay). Moreover, regardless of the result obtained, doctors advise repeating the test at least 1 more time after a few days: the level of hCG in the urine of a pregnant woman doubles every second day.

It should be recognized that in some cases the test does not show the onset of pregnancy for quite a long time. This may indicate the development of the fetus with pathologies or ectopic. But also many of these pregnancies are quite safe, it's just that hCG in women does not grow as rapidly as usual.

In order not to worry in vain, in cases where the situation remains in question, it is better to immediately contact a gynecologist. Keep in mind that ultrasound very rarely “sees” a fetal egg in the uterus in the first days of delay, so it’s better not to rely on ultrasound in this sense. But if you want to make sure for sure whether you are pregnant or not, when the test result is in doubt, then the right decision would be to take a blood test for hCG: this study is considered the most accurate!

It is clear that folk methods in this case are generally unreliable. There can be no talk about their accuracy, the doctors are sure. Meanwhile, practice shows that in almost half of the cases the results of people's tests coincide with the real ones. Most often, girls discuss on forums the reliability of pregnancy tests with soda and iodine. And for half of those who tried these methods, the result was correct. So if knowing the real picture is not so important for you, then you can “tell fortunes” - on soda, iodine, or in another way. Otherwise, such methods cannot be trusted.

Be sure to visit a doctor if the test showed a positive result: you need to make sure that the embryo develops in the right place and there are no violations. It is also necessary to visit a gynecologist in the case when the test is negative, but there is still no menstruation.

Especially for - Ekaterina Vlasenko