When the test erroneously shows 2 stripes. Can a pregnancy test be wrong?

Why do rapid tests for determining pregnancy at home sometimes make mistakes? What is the problem that can cause joy or, on the contrary, disappointment?

According to statistics, the rapid test produces an erroneous result in 1-3% of cases. Let's try to figure out how accurate it is, and in what case you should trust pregnancy test strips.

How does a rapid test determine pregnancy?

If pregnancy has occurred and there is a suspicion, the test is recommended to be used in the morning, when the girl’s urine contains the maximum large quantity HCG (human chorionic gonadotropin), produced by the future baby. A pregnancy test determines its presence by reacting substances with a dye - as a result, the second strip acquires color. If the pregnancy is early, it is not too bright shade. The older the fetus, the more intense the color of the second stripe on the express test.

If the urine does not contain hCG, only one line is visible - this is negative test for pregnancy. But not always...

Why does a false negative pregnancy test occur?

Some expectant mothers on thematic forums complain that the pregnancy test showed an erroneous result at a time when they were already expecting a baby. This is possible, but the error is most often associated with incorrect application of the test.

A false negative result occurs when testing is too early in pregnancy. For example, before a delay, when the amount of hCG in the urine is still too small.

A pregnancy test can detect the presence of hCG, the level of which in the urine reaches at least 20-25 mIU/ml. And this is possible only 7-10 days after fertilization. After a week and a half, the amount of hormones begins to increase - doubling every 2-3 days. Therefore, it is important to take a pregnancy test only after ten days of the expected date of conception.

But why can the test be again false negative? There are several reasons for this. Among them:

• . In this case, the amount of hCG is several times less than during normal pregnancy;
• frozen pregnancy. If the fetus stops developing almost immediately after conception, the hCG content does not increase, and the rapid test is not able to “identify” changes in your body;
• consumption by a girl before an express test large quantity water or other liquid;
• use of diuretics;
• kidney diseases and of cardio-vascular system.

Can an electronic pregnancy test make mistakes?

Are pregnancy tests often wrong? Their manufacturers honestly warn that the possibility of error is 1-5 percent.

Is it possible electronic test be mistaken for pregnancy? Or is it still more informative and reliable?

How electronic pregnancy tests work: they detect pregnancy by changes in the level of hCG in the urine. These tests have a special strip that can either be dipped into a container with urine or placed under the stream. The result is visible in 3 minutes. If it is “+” or the inscription “pregnant”, there is a pregnancy; if the symbol “-” or the inscription “not pregnant” appears, there is no pregnancy.

Many manufacturers of electronic tests recommend using their products from the first day of expected menstruation. However, it is believed that even before the expected start of the cycle, the accuracy of the test is quite high. According to statistics, four days before the expected cycle, 51% of women received the “pregnant” result, three days - 82%, two days - 90%, one - 95%.

Are pregnancy tests often wrong?

Often women planning to conceive are interested in: “Can a pregnancy test be wrong?” Yes, and this probability is from one to five percent. It is known that the test may not “see” pregnancy or, on the contrary, show it in its absence.

How often are pregnancy tests wrong?

• An incorrect result may occur if the test is overdue;
• if its production technology was violated and the test was defective;
• used stale urine for testing;
• at ectopic pregnancy;
• if the pregnancy is too short;
• for diseases of the female reproductive system;
• after a miscarriage or abortion.

Can a positive pregnancy test be wrong?

In some cases, a pregnancy test gives an erroneous result “on the contrary” and shows two lines. Compared to a false negative test, this happens much less frequently.

False positive pregnancy test may occur;

• 2-3 weeks after the birth of the child, since in female body also contains hCG;
• after an abortion or surgery to remove an ectopic pregnancy;
• a few weeks after the miscarriage;
• with gestational trophoblastic tumor - a rare malignant disease that affects placental tissue;
• when taking hCG drugs;
• when ovarian cysts appear.

Can a pregnancy test be faulty?

If the rapid test deceived you, the culprit may not only be due to the peculiarity of your health condition. For example, the test may have been stored in inappropriate conditions, expired or of poor quality.

The popularity of pregnancy tests among women is incredibly high and stable. It’s not strange, because such diagnostics are anonymous, can be carried out at home, and indeed anywhere - almost anywhere at any time. This method of determining pregnancy is convenient, simple, accessible, inexpensive and, last but not least, quite reliable. The accuracy of the tests reaches very high mark, which our women successfully use.

However, despite such a long list of advantages, unfortunately, it can make mistakes, and in both directions: show both a false positive and a false negative result. Moreover, this does not happen as rarely as it was previously thought. That is why doctors increasingly recommend not trusting home tests, and if you suspect pregnancy, immediately go to an appointment with a gynecologist.

There are many different reasons for an erroneous test result:

1. The test may turn out to be of poor quality (violation of production technology) - it is better to choose expensive ones (besides, they are more sensitive and accurate).
2. The test may be expired - so always check the expiration date.
3. Violation of storage conditions: you can only use the hermetically sealed device and print it immediately before testing.
4. Incorrect use of the test system: read carefully before performing the procedure.
5. Using stale urine may give an erroneous result.
6. Very short period of time pregnancy: the level of concentration of the hormone gonadotropin is not yet sufficient for the test to detect it (you should know). The same applies to the situation when pregnancy occurred immediately before the start of menstruation (the result of late ovulation).
7. A negative result in the early stages is also possible with the development of an ectopic pregnancy - in this case, gonadotropin is released more slowly.
8. A false negative result is possible when there is a threat of miscarriage, when hCG is significantly lower than during a normal pregnancy.
9. In case of miscarriages, abortions, removal of ectopic pregnancy hCG hormone does not immediately disappear from the body, so pregnancy tests may show false positive results.
10. A false result is possible in the presence of certain diseases. Positive, for example, in the case of the development of a tumor process in organs reproductive system when the level also increases. Negative - for kidney disease.
11. The test can show the presence of pregnancy if there is no pregnancy if you take medications that contain hCG. These are medications used by injection, such as Pregnil, Profasi and others. After the last use of such drugs, you must wait 10-14 days, otherwise the test result will be false positive.
12. Excessive fluid intake can greatly dilute the urine, which could theoretically make it difficult to detect the hCG present in it. Therefore, it is not advisable to change the usual amount of fluid consumed before testing, or even better not to drink anything at all for 4 hours.

In view of all this, it is always necessary to re-test after 3-4 days. Of course, this diagnostic method does not replace gynecological examination, which is mandatory, regardless of the test results, if your period has not arrived. Never trust the test 100%, so as not to be disappointed and discouraged later. Remember, error is always possible.

Is it possible for a pregnancy test to be wrong? modern world? Couples planning to become parents often ask themselves this question. Those who avoid pregnancy also have to be interested in this topic. In this area, even 1-2 days play a huge role. For example, at a certain time " interesting situation"Abortion is performed only by medical indications. If pregnancy is diagnosed early, pregnancy can be avoided. similar situations.

Types of tests

The likelihood of a pregnancy test being wrong often depends on several factors. Among them are:

• strip strips;
• tablet;
• jet;
• electronic.

All tests have the same operating principle. But can a pregnancy test be wrong? Reviews about similar events left by women quite often. And therefore it is worth noting that home pregnancy diagnosis is not always accurate. The probability of errors is not high, but it does happen.

Test accuracy

How often are pregnancy tests wrong? And why does this happen?

The point is that accuracy modern tests pregnancy depends on several indicators. Namely from:

• sensitivity (most devices have a sensitivity of 25 mMe);
• of its type;
• time of inspection;
• diagnostic techniques.

In general, modern devices for home pregnancy diagnosis are 95-98% accurate. Especially if you follow the technique for obtaining results.

The most common mistake is strip strips. On the day of delay, its accuracy is about 90%. Tablet devices offer to determine pregnancy from the first day of absence of menstruation with a probability of 92-95%, inkjet devices - 95%, digital devices - 99%.

However, no one is safe from pregnancy test errors. To reduce the likelihood of a false result to a minimum, it is recommended to understand the technique of performing home rapid pregnancy diagnostics.

Instructions: how to do the test

There is a chance of an error in a pregnancy test, but it is not too high - from 1 to 10%. This is quite normal phenomenon, because at first even doctors can accept ovum without a heartbeat for a tumor or other neoplasm.

Here are techniques for properly performing pregnancy tests at home:

1. Unpack the strip strip. Collect some morning urine in a sterile container. Before doing this, it is recommended to wait 2-3 seconds. Let the very first urine “merge” a little. This will help avoid mistakes. Next, you need to lower the strip strip to the control value for 5-10 seconds at collected urine and place the test on a flat, dry surface. The result can be assessed after a maximum of 10 minutes.
2. Tablet test for pregnancy is more accurate. It usually comes with everything you need to carry out diagnostics. You need to collect urine in a container and then put it into a pipette. Drop onto a specially designated window area and wait. The indicator on the tablet will indicate pregnancy or its absence.
3. Inkjet tests eliminates the need for urine collection. This greatly simplifies all diagnostics. It is enough to place the device with the receiving end under a stream of urine for a few seconds, then place it on a dry, clean and flat surface.
4. Electronic tests are different. Most often they are used like inkjet or tablet. In some cases, the gestational age even appears on the device screen.

There you have it: pregnancy test error will be minimal if you follow these instructions. Especially if you do not diagnose it before your period is missed.

Main reasons for a false negative test

In what cases is a pregnancy test wrong? This can happen under various circumstances. Moreover, the girl is capable of encountering different diagnostic test results various companies.

Most often, false negatives occur when:

• pregnancy was diagnosed incorrectly;
• the check was carried out too early;
• the test has expired;
• the diagnostic device was stored incorrectly;
• the girl used stale urine;
• hCG level in view of individual characteristics the body is too small;
• During pregnancy, pathologies were revealed (threats of miscarriage, ectopic position);
• taking diuretics or hormonal drugs.

Of course, we should not forget that pregnancy test manufacturers offer different quality of their devices. The Clearblue test is distinguished by its accuracy. Devices from this manufacturer are being used more and more often. Evitest also makes me happy.

Practice shows that pregnancy test errors occur with cheap diagnostic devices. "BiShur" or "NauNow" are issued more often than others false result pregnancy. It is recommended to always remember this, especially when choosing a pregnancy test manufacturer.

False positive rate

It’s hard to believe, but a second line on a pregnancy diagnostic device can also appear due to an error. Pregnancy tests are wrong. It is a fact. And therefore, doctors recommend not checking for the success of conceiving a baby before a missed period.

False positive result appears on pregnancy tests if:

• a woman undergoing treatment for infertility;
• hormonal medications were discontinued less than 10 days ago;
• the girl has tumors or inflammation;
• a woman recently had a miscarriage;
• an abortion performed some time ago.

As practice shows, an error in a pregnancy test can cause a lot of trouble. You have to either repeat the diagnosis or clarify it.

Faint stripe - how to interpret

Some girls experience a “ghost” appearing on the corresponding device during verification. This is the second, but pale and weakly expressed, barely noticeable stripe. How to interpret such a reading?

Of course, ideally it is recommended to repeat the diagnosis the next day. Another "ghost"? Then it is better for the woman to clarify the result or carry out another home test in a couple of days or contact a gynecologist who can determine pregnancy with greater accuracy.

Most often, a "ghost" is a positive result. It may appear when:

• low hCG levels;
• early diagnosis pregnancy;
• pregnancy pathologies;
• ectopic pregnancy.

This phenomenon can also be considered a false positive. As a rule, the second faint stripe- it's just a reagent. Clearblue and Evitest tests are distinguished by their quality and their reagents rarely show up as a “ghost”. This is good news.

Device defect

Can an electronic pregnancy test make mistakes? Yes, but this happens extremely rarely. To minimize the likelihood of errors, a woman is recommended to undergo treatment before planning a baby, and then follow the previously suggested instructions.

In what cases is a pregnancy test wrong? This can happen if a girl bought a defective device. No one is immune from such situations, so it is recommended to accurately diagnose an “interesting situation” by purchasing several tests from different manufacturers.

Important: defective devices show both false negative and false positive results.

Clarification if necessary

How often are pregnancy tests wrong? Modern home pregnancy diagnostic devices offer accurate detection successful conception with a probability of 90-99% on the first day of missed menstruation. A few days before this, the test may show exact result, but this is extremely rare. Why? HCG level before delay critical days is at very low levels. That is why it is better not to rush into diagnosis.

How can I check the results of a pregnancy test? A girl can:

• repeat the study after a few days;
• donate blood for hCG;
• go to the gynecologist;
• make a small pelvis.

All this helps to determine pregnancy with a higher probability than just a quick test done on time.

Important: an ultrasound can listen to the fetal heartbeat. This becomes possible at approximately 5-6 weeks of pregnancy.

Does a pregnancy test ever go wrong? Unfortunately yes. If you do not choose a device for diagnosing an “interesting situation” and buy the cheapest one, you may encounter false readings.

Is there any way a woman can reduce the likelihood of a pregnancy test error to a minimum? Yes, but not 100%.

Here are tips to help avoid false results when diagnosing pregnancy at home:

1. Carefully choose the manufacturer and type of pregnancy test.
2. Check the expiration date of the pregnancy testing device.
3. Do not carry out diagnosis until menstruation is missed.
4. Perform all manipulations with the dough according to the instructions.
5. Do not drink a lot of water before the diagnosis and do not take diuretics.
6. Repeat the check a couple of times at some interval.
7. Do not use old urine when carrying out diagnostics.

All this really helps to cope with the task. Unfortunately, diagnosing pregnancy in the early stages is not always easy. And therefore you have to use several ways to check the success of conception.

Today, to determine pregnancy or its absence, the almost absolute majority of women primarily use home rapid tests. It's accessible, simple, convenient and fast. And almost always, or rather in 97-99% of cases, the test gives a reliable result. What about the remaining 1-3%? For what reasons can a pregnancy test be wrong?

How does a pregnancy test work?

To get to the bottom of this, you need to understand how the test works. If we discard subjective feelings, then early sign the onset of pregnancy is the production of hCG (human chorionic gonadotropin) by the embryo, which is released not only into the blood, but also into the urine of the pregnant woman. It is this hormone that the test reacts to.

Speaking in simple language The absorbent part of the test strip, which is immersed in the urine sample being tested, contains a substance chemically bound to the dye. If there is hCG in the urine in the area of ​​the “pregnant strip”, where another component is contained, a reaction occurs that releases the dye, and we see a colored line (most often crimson or of blue color) more or less bright, depending on the concentration of hCG. If the specified hormone is absent, then no reaction occurs and the strip does not color.

The “control strip” contains a reagent, upon interaction with which the dye is released in any case, regardless of whether there is hCG in the urine or not (even if the water is tested).

False negative result

It must be said that a false negative result (that is, there is a pregnancy, but the test does not show it) is much more common than a false positive. In most cases, the reason for this is untimely testing, or, simply, haste. The declared maximum sensitivity of rapid tests, or rather, the minimum amount of hCG to which the test reacts, is about 20-25 mIU/ml (in practice - about 50). The concentration of hCG in the blood serum reaches this value only on days 7-10 after fertilization and continues to double every 2-3 days. Urine contains approximately half the amount of the hormone than blood. Therefore, the test can be done no earlier than 10 days after fertilization, and to obtain reliable result– as the manufacturers advise – from the first day of missed menstruation. Other reasons for a false negative pregnancy test result include:

• Drinking large amounts of liquid or diuretics before the test.
• Diseases of the kidneys and cardiovascular system that prevent release of hCG in sufficient concentration.
• Biochemical pregnancy or threat of miscarriage. At the same time, the concentration of hCG decreases.
• Ectopic or frozen pregnancy. The hCG content is lower than during intrauterine pregnancy.

False positive result

False-positive results are less common than false negatives, since the reasons for their appearance in the body women hCG without pregnancy, not so much. For example, the test may show 2 stripes:

• For several weeks after childbirth (both vaginal and vaginal caesarean section).
• After a miscarriage, removal of an ectopic pregnancy or abortion.
• In the presence of trophoblastic tumors producing hCG (with hydatidiform mole, chorionepithelioma, etc.).
• While taking hCG drugs (approximately 10 days after the last administration). To obtain a reliable result, it is necessary to do a quantitative analysis of the hCG content in the blood serum at least twice with an interval of 2-3 days. A decrease in hCG concentration indicates that there is no pregnancy.

Other causes of errors

There are also a lot of factors in which tests can be wrong, in any direction:

How to avoid mistakes?

In order not to have false hopes and not to be needlessly upset when performing the test, you must strictly follow the instructions. However, the following steps can be taken:

• Do not one, but several tests, if possible, from different manufacturers.
• Repeat the test after 2-3 days, regardless of the initial result.
• Donate blood for hCG analysis, preferably over time (with an interval of 2-3 days).

A little girl asks: “Dad, are two stripes good?” And dad immediately felt bad...

Two stripes are the result. Some have been waiting for it for many months or years, doing everything possible and impossible for this, but for others they are seriously frightening or shocking. There are different life situations, but it is necessary to determine or refute the presence of pregnancy, almost 100% of girls and women first turn to home tests. And often even before they experience a delay.

A home pregnancy test is definitely a good thing. It is accessible to each of us, simple and easy to use and quite informative. Today there are four generations of tests, each successive of which is more advanced. But they are all built on the same principle: a special reagent reacts to hCG in a woman’s urine (if this hormone is present there) and appears in the form of a second strip. Actually, this means that you are pregnant. But is it always?

Can the test show a false result?

We have already written a lot about. And if you read forums on the Internet on this topic, you will immediately be convinced that, and even often. That is why it is not recommended to end the study with one test, but always to carry out control with repeated testing after a few days.

A pregnancy test may well show a false result - either negative or positive. A false positive result is the appearance of two lines on the test in the absence of pregnancy.

As we have already said, the second strip appears if a woman’s urine contains the hCG hormone, which begins to produce chorion immediately after fertilization. Every day the hCG level increases, and the closer to the delay (and according to all rules, no earlier than the next day after the missed period) you test, the greater the likelihood that the reagent will react.

However, in a number of cases human chorionic gonadotropin person in small quantities produced in the body for other reasons not related to the development of pregnancy in it. And then a test carried out against the background of hCG production may show two stripes, but this will not mean at all that the girl is pregnant.

Causes of a false positive pregnancy test

Causes of false positive pregnancy test results may include trophoblastic tumors (which are caused by the proliferation of the same cells that are responsible for producing hCG), a recent abortion, or spontaneous miscarriage, termination of an ectopic pregnancy - when the hCG that has grown against the background of a previous pregnancy in the woman’s body has not yet had time to decrease. In addition, there are many medical supplies containing hCG, and while taking them, a pregnancy test may also show false positive result. This happens if a woman, for example, is being treated for infertility with hormonal therapy or just a few days ago (no more than ten) stopped taking hCG-containing drugs.

Often, girls observe so-called ghost stripes on the dough sheet - blurry, indistinct, barely noticeable second stripes or appearing only at a certain angle or in certain lighting. In some cases, this may indicate that the level of hCG in the urine is still quite low, and the test should be repeated after 2-3 days for greater reliability. But most often, ghost strips appear if the test was stored in incorrect conditions, it has expired or is of low quality. The second indistinct line only indicates that this place contains a reagent that would manifest itself in the presence of pregnancy.

If you doubt the result of a pregnancy test, you need to take a blood test for hCG and undergo an examination by a gynecologist. In any case, this will not hurt and will either confirm the test result or refute it.

Of course, all of the above does not mean that home tests are not suitable for research and always lie. In 97% of cases they show reliable results.

However, you should not take 2 strips of a pregnancy test as a final verdict until examined by a doctor. In the same way, consider 1 strip as one hundred percent absence of pregnancy. By the way, false negative results happen much more often than false positive ones.

Especially for- Elena Kichak