Nutrition and diets 

If the test is positive and there is no pregnancy. What to do if the test is positive. Reasons for a false positive test

  • Home pregnancy test: how it works
  • Reason 1. Failure to meet the test check time
  • Reason 2. Recent miscarriage or abortion
  • Reason 3. Chorionic adenoma (molar pregnancy, hydatidiform mole)
  • Reason 4. Taking medications
  • Reason 5. Diseases
  • Can pregnancy tests be trusted at all?
  • What to do if the pregnancy test is positive

Home test systems for determining pregnancy are very popular today, they are so simple and reliable to use - manufacturers talk about 98 and even 99% reliability of the results. If you are wondering what is wrong with that 1%, then here are five reasons why a pregnancy test can be false positive.

Home pregnancy test: how it works

Home pregnancy tests are based on determining the concentration of one of the hormones - human chorionic gonadotropin (hCG) in the urine. With the onset of pregnancy, the level of this hormone in the blood of a woman rises sharply, and it can be detected both in the blood and in the urine.

There are several varieties of home pregnancy tests, and usually the manufacturer gives clear and detailed instructions on how to use them. So, some test strips must be lowered to a certain level in a container with urine, others need to be urinated (or a drop of urine on the contact area of ​​the test).

Depending on the choice of the manufacturer, a “+” sign, the words “yes”, “pregnancy” may appear on the test strip of a pregnant woman, but most often - two indicator lines. One of them appears in any case (this confirms that the test is working, and you followed the instructions exactly), the second - only with an increased level of hCG in the urine, that is, it indicates pregnancy. The second strip may be noticeably paler than the first, but still indicates a positive result. It is with these tests that women make the most common mistake.

Reason 1. Failure to meet the test check time

All tests have a time interval when the result should appear clearly and clearly - usually not earlier than 3-4 minutes after contact with urine and not later than 10-30 minutes after. If you look at the test later, after an hour or more, then for the second strip you can take the evaporation line - the border to which urine has risen along the test strip. After the dough dries, the dividing line becomes clearly visible, and it can be confused with an indicator strip.

Always strictly follow the test system manufacturer's instructions!

Reason 2. Recent miscarriage or abortion

After an abortion (natural or artificial), the level of hCG in a woman's body decreases, but, of course, not immediately. In some cases, it may take up to 35 days before the concentration of this hormone returns to normal, and the average time interval for establishing hormonal balance is 19 days. Of course, a pregnancy test during this period will show a false positive result.

If you have had a miscarriage or an abortion, you have used contraception, and your pregnancy test remains positive after three weeks, this is a reason to get a medical examination. Part of the placenta may remain in the uterus, which continues to produce hCG. If you do not take any measures, then in the future it will lead to inflammation and serious health problems.

Reason 3. Chorionic adenoma (molar pregnancy, hydatidiform mole)

A rare in Russia (according to various sources, one case per 1000-3000 pregnancies) but quite common in the countries of the Far East (one case per 120 pregnancies), a genetic anomaly in which the maternal chromosome is “lost” during conception, and the non-viable embryo contains either only the father’s chromosomes , or a double set of chromosomes of the father and one - of the mother. There may not even be a fetus at all, but at the same time, a pathological proliferation of placental tissue occurs.

This pathology is easy to identify with ultrasound, but if a woman does not go to the doctor, then she may consider herself pregnant for some time: her stomach grows, she suffers from toxicosis, and the results of the test strip inspire confidence. However, chorionadenoma is a dangerous pathology that can provoke severe uterine bleeding and the formation of a malignant tumor. Pathology is rare, but let's not forget about it!

Reason 4. Taking medications

The vast majority of medications, as well as foods (including alcohol) do not affect the results of a pregnancy test. The only exception is drugs that contain hCG (they are used to treat infertility). If you are taking these drugs on the advice of your doctor, you will need to choose another way to test for pregnancy.

Reason 5. Diseases

Various diseases can affect the level of hCG in the body. It changes when:

  • premenopause or menopause;
  • oncological diseases of the ovaries, bladder, kidneys, liver, lungs, colon, breast and stomach;
  • kidney disease or urinary tract infection;
  • ovarian cyst.

In addition, there is the so-called "phantom hCG" - the chemicals in the pregnancy test can react with them in the same way as with the hormone itself. The doctor finds out that we are talking about “phantom hCG” by determining the content of chorionic gonadotropin by other methods. If the results of different tests differ significantly (sometimes by dozens of times), then we are talking about just such an error.

Can pregnancy tests be trusted at all?

Can! But it must be remembered that it varies greatly in different women and at different points in pregnancy. It reaches its maximum at 8-9 weeks after conception. If you are anxious to find out about a positive result and you try to take the test before the date of the expected period, then it is very likely that you will get a false negative result. It is much more common than false positive.

What to do if the pregnancy test is positive

If a pregnancy test shows a positive result, you must notify your doctor. Only a specialist can confirm whether you have a normal pregnancy or a false positive test result.

If the test shows a negative result, but you still think that pregnancy is possible, you should also consult a doctor.

The accuracy of the pregnancy test is high - 99%. But do not forget that someone falls into the 1% of exceptions!

According to medical news today

In view of the fact that we often so want to see the cherished // stripes, and sometimes we will even "see" them - I have collected several articles. This information may be useful. (sorry if this has already been posted)

First, an article about the frequently mentioned "liar" frautest!

FRAUTEST test

C (c o ntrol) - control zone. The appearance of this strip during the study shows that everything is in order with the system itself, the test result is RELIABLE.
T(test ) is the test zone. This strip, reacting to hCG in the urine, appears in the test zone and informs about the presence of pregnancy.

We draw your attention to the fact that the strips on the dough must be even., approximately the same color (although in early pregnancy, the test strip may be slightly lighter than the control) and placed across the entire width of the control zone.

Also follows doubt a positive test result if the strip is blurry, barely visible or located at the junction of the plastic protective substrate and the base of the test (at the test strips).

Also, a white stripe should not be considered a positive result.. A white stripe is a reagent that did not appear, which became visible due to the large amount of the test liquid that got into the test. In other words, if the woman were pregnant, then this reagent would stain and as a result, the test would show two full-fledged strips.

FALSE POSITIVE (no pregnancy, but the test shows a positive result).

Possible reasons:

- taking fertility drugs containing hCG (pregnyl, profazi) at the time of the test or if the time after the end of treatment is less than 10 days;

- the presence of tumors (chorion epithelioma of the uterus or hydatidiform mole);

- incomplete removal of embryonic tissue after a previous abortion.

FALSE NEGATIVE (there is a pregnancy, but the test shows a negative result).

Possible reasons:

- the test was carried out ahead of schedule (especially this result can be observed in women with an irregular menstrual cycle);

- pathology of the kidneys and the cardiovascular system, which prevents the release of hCG in the urine in normal concentrations;

- high fluid intake or diuretics before testing.


The mechanism of "work" of the pregnancy test

In pregnancy tests, immunochromatography is used - a type of chromatographic analysis based on the interaction of a substance (usually of a protein nature) with antibodies to it. The body's immune system works on the same principle of antigen-antibody interaction, hence the name.

The substance to be determined is human chorionic gonadotropin (hCG), a glycopeptide hormone secreted by the placenta during pregnancy. The appearance and rapid increase in the concentration of hCG in the body (and in particular, in the urine) of a woman makes it a fairly reliable sign of pregnancy. Usually, on the 7-10th day after fertilization, the concentration of hCG reaches 25 mIU / ml (international units per ml) and doubles every 2-3 days, reaching a maximum between the 8th and 11th weeks of pregnancy, and then decreases almost to zero by the beginning of the 3rd trimester. 25 mIU / ml is the minimum concentration of hCG detected using immunochromatographic tests.

How many days after ovulation can you test?

In principle, a positive result can be obtained already on the 7th day of post-ovulation. Embryo implantation takes 6-12 days, usually about 10 days. So it makes sense to wait 10-12 days after ovulation, but even then there are often false negative results (i.e., there is a pregnancy, but the test is negative).

Tests from different manufacturers have different sensitivities, most of them are designed to be used from the 1st day of a missed period. In 90% ± 5% of cases, by this time the embryo has already implanted in the uterine wall and begins to produce hCG. However, in 10% of cases, implantation has not yet occurred. With a delay of 1 week, implantation occurs already in 97% ± 3% of cases. However, in practice, the reliability of the tests is limited by their sensitivity, so the real reliability is somewhat lower. Since the hCG level doubles every 2-3 days, the recommendation follows: if the result is negative, if menstruation does not begin, repeat the test after a few days.

What do false positive and false negative test results mean?

A false positive result is when the test shows two lines in the absence of pregnancy. This happens when a woman takes drugs containing hCG, as well as with trophoblastic tumors. After a spontaneous miscarriage or early abortion or removal of an ectopic pregnancy, hCG remains in the body for some time, and the test gives false positive results (i.e. there is no longer a pregnancy, but the test is still positive). As in the case of taking drugs containing hCG, two quantitative determinations of hCG with an interval of 2-3 days are necessary to obtain reliable results. A decrease in the level of hCG indicates that the pregnancy is no longer there. Thus, false positive results are relatively rare, in contrast to false negatives. The latter are obtained when the gestational age is still too short and the hCG level is too low to be detected by the test (or the test itself is not sensitive enough).

The validity of a home test depends on various reasons:

  • The quality of the test itself. Products from different companies can vary significantly.
  • Expiration date of the test, conditions and place of its storage. It is believed that in most cases the test can be trusted, provided that it is bought at a pharmacy.
  • The state of pregnancy. In a pregnancy that is on the verge of miscarriage, hCG will be produced much less than in a normally developing pregnancy.
  • Conditions for setting the test: the study must be carried out using the morning portion of urine, in which the maximum content of the hormone is observed; the evaluation of the test must be carried out, adhering to the time interval specified in the instructions.
  • Additional circumstances. The amount of hCG in the urine is affected by the diet and the functional state of your kidneys.
  • If you drank a lot of liquid the night before, or ate watermelon, or are taking diuretics (diuretics), the concentration of hormones in the urine will be too low, and the test will not notice them.
  • If you have protein in your urine (even if you don't know anything about it), the test may give an incorrect result.
  • If you were injected with hCG to induce ovulation (Profazi, Pregnyl) or to maintain the luteal phase, then traces of this hormone may remain in your body for 10 days after the last dose of the drug, and, accordingly, a pregnancy test may give a false positive result.
  • Also, the level of hCG can be determined several weeks after normal delivery, caesarean section, spontaneous or medical abortion, and in other cases mentioned above.

As a result, you can get incorrect information, and in both directions: there is no pregnancy, but the test seems to be positive. Or: there is a pregnancy, but the test is still negative. Both of these can be a source of great suffering.

Some tests in the absence of pregnancy show its presence (false positive result). On the contrary, there are situations when there was a pregnancy, and the test showed its absence (a false negative result).

What are the reasons for the so-called false positive and false negative results?

Often the cause of a false result is an incorrect test or the use of an expired test.

With the introduction of hCG to induce ovulation (drugs "Profazi", "Pregnil") or maintain the luteal phase of the cycle, traces of this hormone can remain in the body for 10-14 days after the last dose of the drug, and, accordingly, a pregnancy test can give false positive result.

Alcohol, fatigue, stress, lactation, taking medications (including birth control pills and Postinor) do not affect the test results.

The cause of false positive results may be a tumor that produces hCG - chorionepithelioma or cystic mole, dysfunctional ovarian diseases, when the production of various sex hormones is impaired.

After a spontaneous miscarriage or early abortion or removal of an ectopic pregnancy, hCG remains in the body for some time, and the test gives false positive results.

May show incorrect results. The entire set of pregnancy test errors is usually divided into two types - false positive and false negative results. False-positive results include the detection of pregnancy in a non-pregnant woman. And false negative results include, respectively, the failure to detect pregnancy in a woman who actually became pregnant.

False positive pregnancy test results may be due to the following causal factors:

  • The use of drugs to stimulate ovulation containing human chorionic gonadotropin (for example, Profazi, Pregnil, Ovitrel, etc.);

  • Various tumor formations of the uterus, ovaries, kidneys, lungs and intestines;

  • Increased production of chorionic gonadotropin in brain structures - the pituitary gland, for example, with tumors or traumatic brain injuries;

  • kidney disease;

  • Childbirth, abortion or miscarriage less than 1 month ago.
Thus, false positive pregnancy test results can be associated with various diseases that require qualified treatment. Therefore, when a false positive result of a pregnancy test appears, it is recommended to undergo a comprehensive examination in order to find out the reasons for the increased level of chorionic gonadotropin.

False negative pregnancy test errors can be due to the following reasons:

  • Too early analysis;

  • Diluted urine;

  • Incorrect analysis.
That is, a false negative result of a pregnancy test does not indicate any disease.

The most common false positive and false negative pregnancy test errors are due to the following causal factors:

1. Too little pregnancy. If a test with a sensitivity of 20 - 25 IU / l is used, then it will only be able to correctly diagnose the presence of pregnancy for a period of at least three weeks. Thus, this type of test can only be done 15 to 17 days after the last unprotected intercourse. If the test is done before the 15th day from the moment of the alleged conception, he will show a negative result, that is, he will be mistaken. Due to the fact that sexual contact, which resulted in pregnancy, could occur literally 1 to 2 days before the estimated date of the next menstruation, doctors and scientists recommend doing a test with a sensitivity of 25 IU / l no earlier than 2 weeks of delay. In this case, the test will fail. If a pregnancy test with a sensitivity of 10 IU / L is used, then it must be done 7 to 10 days after unprotected intercourse. However, if a woman became pregnant 2 days before the start of the next menstruation, then on the 2nd - 3rd day of the delay, the test will show a negative result, since 7 - 10 days have not yet passed from the moment of conception. That is, the test will fail. That is why doctors recommend doing a test with a sensitivity of 10 IU / L only after 7 days of delayed menstruation;

2. Unsatisfactory quality of urine. For a pregnancy test, morning urine should be used, since it is in it that the maximum concentration of human chorionic gonadotropin. During the day, a woman can drink a lot, as a result of which the urine is diluted, and the concentration of gonadotropin decreases. In such a situation, a pregnancy test will determine the concentration of human chorionic gonadotropin in dilute urine and may be mistaken by showing a negative result;

3. Incorrect use of a pregnancy test. The test should be done strictly according to the instructions, and the result should be evaluated after a specified period of time. If the test was performed incorrectly, the result may be erroneous;

4. Kidney disease. With kidney pathology, the level of chorionic gonadotropin in the urine during pregnancy may not increase. In this case, the test will show a negative result, even if everything is done correctly, that is, it will make a mistake;

5. pathology of pregnancy. The test may fail if the pregnancy is ectopic or there is a threat of miscarriage;

6. Weak attachment of the fetus to the wall of the uterus. In this case, there is pregnancy, but chorionic gonadotropin is not produced in sufficient quantities. That is, the result of the pregnancy test will be negative and, accordingly, erroneous.

Pregnancy test and laboratory methods for studying pregnancy

What does almost every woman do in case of an unexpected delay in menstruation? A preliminary appointment with a gynecologist is necessary, tests take time, and in a situation where life can take a new turn, it is simply impossible to wait. For such force majeure circumstances, a pregnancy test was invented, which is easy to purchase at the nearest pharmacy. From the variety of proposed test options, you can choose several different ones for the reliability of the result ... but is it reliable?

What is a test strip?

First you need to understand the design of the test strip itself in order to understand the results it shows. The strip is impregnated with some special reagent that reacts to the hCG hormone found in the urine. Arising in the female body already a day after the fertilization of the egg, human chorionic gonadotropin (hereinafter referred to as hCG) begins to accumulate, becoming the future placenta.

It would seem that everything is simple and clear: conception occurred, a hormone was produced, which was shown by the test. However, false positive tests are much more common than false negatives, and there may be several reasons for this.

Reasons for a false positive test result

  • A defective test and a violation of the instructions for use are the most banal and difficult to calculate reasons. If the expiration date of the goods can be checked when buying at a pharmacy, then the internal filling is no longer possible. Therefore, it is recommended to purchase several tests from different manufacturers and in different pharmacies for greater reliability of the results. When carrying out the procedure, a woman should not rush, but first carefully read the instructions. The test strip is a very sensitive mechanism that requires careful handling. If a particular test strip needs to be dipped into a container of urine for several minutes, then it will not be enough to simply urinate on it, the result will be incorrect.
  • Miscarriage, abortion, removal of an ectopic pregnancy. In all these cases of an ended pregnancy, the hCG hormone will still be present in the woman's body for some time, giving rise to the second strip. This situation is most likely with a miscarriage at a very early date, when a woman may not even notice what happened. If a pregnancy test is carried out during this period, it will definitely give a false positive result.
  • Cyst and other tumor formations. Ovarian cyst, stomach, neoplasms in the pancreas, liver, colorectal cancer, stomach cancer can confuse the test strip. Therefore, if there is any doubt about the sudden "pregnancy", it is worth contacting a gynecologist for a comprehensive examination. Thus, it is possible to detect a serious disease in time and start treatment in a timely manner.
  • Medications. Some medicines, for example, drugs that stimulate ovulation, contain the same hCG hormone. Therefore, even after the end of the course of taking the drug, you should not rush to conduct the test - hCG will be excreted from the body for at least 2 weeks.
  • Hormonal failure and menopause. Any violation of the hormonal background of a woman leads to impaired immunity, various diseases and the production of hormones, including hCG, affecting the test results. During menopause, the level of the hormone can also be slightly elevated, especially in the first time after the cessation of menstruation, and give a false positive test result.

A pregnancy test at home does not at all examine the female body for pregnancy in general, and for the presence of an embryo in the uterine cavity in particular. He just looks at the level of the hCG hormone, which is not at all a clear sign of pregnancy and may signal a different source that causes the production of this hormone. Even in men, the level of hCG can be increased due to diseases such as seminoma or testicular teratoma, oncological diseases. Therefore, only an appeal to the attending physician can provide comprehensive information about all the processes occurring in the body.

Nowadays, to find out the reason for the delay in the onset of menstruation, it is enough to buy a pregnancy test at the pharmacy. Such test methods, carried out at home, give almost 98% reliable results. Nevertheless, one can often hear the question: “Can a pregnancy test be false positive?”. Unfortunately, there are many errors in testing and you should be aware of them and take into account.

Sometimes the express method can determine a positive test in the absence of pregnancy. That is, there are two strips on the indicator line, but the woman is not in position. In what cases can a test show false data? What do we have to do?

Pregnancy diagnostics

The diagnostic device consists of a strip impregnated with a special reagent. As soon as a woman becomes pregnant, chorionic gonadotropin begins to accumulate in her urine almost from the first days. It is he who interacts with the reagent, appearing visually in the form of two strips. But hCG may be present for other reasons, they are not always explained by fertilization.

Expectant mothers should not rush to take tests the next day after a possible conception, it is better to wait for obvious signs of pregnancy.

Among them, the most common:

  • Delayed monthly cycle.
  • Nausea and vomiting, especially in the morning.
  • Irritation.
  • Constant weakness and drowsiness.

The strip is very sensitive, so use it only after carefully reading the insert.

What influences the result?

There is no pregnancy, but the test is positive. This can happen, and more than once. What is the problem? In many situations, the human factor affects, as well as the environment.

We divide the possible causes into small groups:

  • No wonder we are given instructions for use for a particular device. But not every woman carefully studies and, when using, does not always listen to the prompts. For example, this applies to a container for collecting urine - it must be clean and sterile. Violating such a simple point, you can get a false positive test. The reasons why this will happen, I hope you understand.
  • Improper storage of the test in a pharmacy and at home, after purchase. The purchased box should be stored in a dry place out of the reach of small children.
  • Another important point. Errors can be when taking indicators. If you put the strip into a container of urine and immediately took it out to see the results, this is wrong. In any case, the packaging or instructions indicate the required time to wait after you have immersed the test in urine. Most often from 5 to 7 minutes. It is important to understand that the result can be considered positive only if you observe the presence of two clear and evenly colored bands on the test.

As you can see, the reasons for a false positive pregnancy test are different, one of them may be the manufacturer. If poor quality reagents are used, the test response may be inaccurate.

False positive result

A false positive pregnancy test needs a mandatory consultation with a gynecologist. At home, the manipulation is repeated, for this they take a set from another company, for example, Evitest, and the result is determined by a third party, it can be a mother, girlfriend or sister.

Also, the doctor can prescribe a blood test for the presence of a hormone, only thanks to him can you say with confidence "I'm pregnant" or vice versa.

So: if there is no pregnancy as such, and the test answer is positive, then they speak of a false positive answer. If there is a pregnancy, but the answer is negative, they speak of a false negative result.

System errors

The test is positive, but there is no pregnancy - this happens much less often than a false negative answer, and there are reasons for this.

Here are the main ones:

  • The expiration date of the drug has expired or there is a defect in it. When buying products in a pharmacy, be sure to check whether they are still fit for use. If the deadline has passed, it is no longer possible to apply the test, since most often the result will be false. In the case of a marriage, it is more difficult, because when buying, we cannot verify the integrity of the packaging and the test itself. In this case, you will have to repeat the manipulation after a few days, using a strip of another company.
  • Instruction violation. If you use this method of home diagnosis at will, you are guaranteed a false positive pregnancy test. By purchasing a regular test strip and substituting it under a stream of urine, or vice versa, lowering an inkjet test into a container, you violate the correctness of the analysis, or rather, the instructions. The test strip should be kept in a container with urine strictly for the time specified in the instructions.
  • Miscarriages, abortions, or ectopic pregnancies. In the presence of at least one of the listed cases, the level of hCG does not decrease quickly, this takes time. Therefore, when conducting home testing, the result may be positive, but there is no pregnancy. In this case, it is advisable to wait a while. If you are sure of fertilization, repeat the analysis.
  • Tumors in the female body. If menstruation is late, can there be a false positive result? Oddly enough, yes, a positive pregnancy test is due to the presence of an ovarian cyst or tumor formations of both the reproductive system and other internal organs. Therefore, if you have a delay, and the analysis is positive, you should not rejoice ahead of time. In this case, make an appointment with a gynecologist and undergo a complete examination to confirm pregnancy.
  • Taking medications that contain human chorionic gonadotropin. A woman can take medications, such as Pregnyl, to stimulate ovulation. Therefore, it makes no sense to do a test, because the hormone is completely eliminated from the body only after two weeks.

When your result is false positive, you need to take into account all the indicated reasons for the appearance of this indicator. If you feel that any of the items matches your condition, please consult your doctor for advice.

Error rate

From everything that has been said before, you can conclude that you cannot rely on such quick checks, as they often give the wrong answer. But this does not mean that they are of poor quality.

Doctors have their own opinion about this type of diagnosis. According to statistics, in 98% of cases, the diagnosis is correct, which indicates the sensitivity and accuracy of this express method.

Are the tests wrong? Definitely yes. And this should be taken into account in the analysis. In any case, independence in such a matter is inappropriate, only a doctor can help you answer the question of whether you are pregnant or not.

Dear ladies, you should take care of your health, so it’s better to visit a doctor once again than to regret later about the missed time or wasting nerve cells. A pregnancy test will be positive only if all the recommendations specified in the instructions are followed, and also if your egg is fertilized.

So take your time, you can check for pregnancy later. Love yourself and your future children. It doesn't matter if you end up with a false positive test or pregnancy, it's your health that matters most. New life should be born in love, family harmony and good health, so work on yourself before you take such a responsible step and purchase your first test at the pharmacy.