Before the invention of pregnancy tests, humanity resorted to in various ways guessing the onset of the gestation period. Original pregnancy tests were carried out by wetting grain with female urine, mixing urine with wine, changing the characteristics of biological fluid under the influence of various additives, and also injecting it into a certain type of frog. Thus, it was believed that when pregnancy occurs, grains of wheat or barley, watered with urine, germinate faster, which helped not only to diagnose a successful conception, but also to predict the gender of the child. A repetition of a similar test in the 70s of the 20th century showed a 70% effectiveness of the method for determining pregnancy.
A modern pregnancy test makes it possible to determine with a high probability the beginning of a new life without long-term experiments with different compositions and grains. The variety of rapid diagnostic tests, however, requires knowing when to take a pregnancy test, how to interpret the result, and which tests are best to use.
Despite the modernization of diagnostic methods, the material for testing remains the same as in the Middle Ages. Urine contains human chorionic gonadotropin, the same hormone whose concentration is assessed when diagnosing pregnancy using a blood test.
In venous blood, the hCG hormone begins to be detected 2-3 days after the chorionic villi begin to penetrate the walls of the uterus. Human chorionic gonadotropin reaches a concentration sufficient for most tests in the excreted urine approximately a week after the start of the process of its production in the body.
If there is a concentration of hCG in the urine sufficient for the level of sensitivity of the test, a reaction of the chemical on the surface of the test and the hormone occurs. In the absence of the hormone or its insufficient concentration, the reaction does not occur, and the result is negative.
The average sensitivity of tests on the market is 25 mUI; hCG usually reaches this level two weeks after fertilization. Existing tests with higher sensitivity, reacting to smaller amounts of the hormone, diagnose its appearance 3-4 days earlier.
When can I use the test during a regular menstrual cycle?
If the menstrual cycle is regular and has a constant number of days between the onset of bleeding, then calculating the date of ovulation is easy. The middle of the cycle (with a standard menstrual cycle of 28 days - on the 14th day) the egg is released.
Fertilization of an egg is possible within three days, its life cycle. After the process of fusion of the egg and sperm for 4-5 days, the germ cells migrate through the uterus to the placentation site, after which the production of hCG begins. Assuming fertilization within 2 days, 4 days of migration and the time necessary to achieve the desired level of concentration in the urine of the hormone, highly sensitive tests are able to show the onset of pregnancy 10 days after ovulation, that is, with an average cycle of 28 days - on the 24th day of the cycle . For greater confidence, experts recommend using a highly sensitive test on the 12th day after the release of the egg from the ovary, and tests of ordinary sensitivity - after 15-16 days.
Diagnosis of pregnancy with irregular cycles
If the menstrual cycle is not regular, the duration of the periods between menstruation varies, then the time to use the test depends on the date of ovulation.
Ovulation can be determined by subjective sensations (some women feel characteristic tingling in the area of one of the ovaries, a feeling of fullness, swelling, changes in sensitivity, mood), as well as by measuring rectal temperature and using an ovulation test. To determine the onset of ovulation and possible fertilization, a pregnancy test is used 15 days after the due date.
Morning is wiser than evening: when is the best time to take a test?
Most modern test strips do not limit the diagnostic period to any time of day: they can be used in the morning, afternoon, and night. However, experts, taking into account the possibility of a natural decrease in the concentration of hCG after drinking a large amount of liquid, recommend resorting to diagnosis in the morning, using the first portion of urine after a night's sleep, especially if the probable stage of pregnancy is short.
During the day, when fluid enters the body, the concentration of the hormone decreases. For periods more than 18 days after ovulation, this factor is not decisive, but the timing of ovulation also does not always coincide with the expected one. For accurate indicators, it is better to follow the recommendations of specialists, and in a situation where the test needs to be carried out during the day or evening, the optimal diagnosis would be after four hours of abstaining from going to the toilet and limiting the consumption of liquid products to maintain the level of hCG concentration.
Rules for using rapid tests
- It is necessary to follow the test storage rules provided by the manufacturer.
- Using the test in damaged packaging may distort diagnostic results.
- The package is opened immediately before diagnostics.
- Using an expired test will result in incorrect results.
- The optimal time for the test is in the morning, immediately after a night's sleep.
- If the test is not a jet test, urine collection requires the use of a clean container.
- It is recommended to carry out hygienic procedures including washing the external genitalia before testing.
- Strictly follow the instructions for use.
Pregnancy test: instructions for use
There are different types of rapid tests. Instructions for each type are attached to the test; violation of the rules of use most often results in the appearance of incorrect indicators.
When diagnosing pregnancy, the test is used within the time frame specified by the manufacturer. If testing is recommended from the first days of the delay, then there is a possibility that the sensitivity of the reagent or individual characteristics, the timing of conception will allow pregnancy to be detected earlier than the specified period, but most often an accurate result is possible only on the indicated days of the cycle.
The cost of the test most often directly correlates with its reliability: the lower the price, the lower the production cost and the cheaper the chemical reagent, respectively, the higher the quantity incorrect results. The most common tests on the market today are four modifications; each type has its own characteristics and instructions for use. Some manufacturers produce different types of tests under a single brand (Evitest or Evitest, Frautest, etc.); when purchasing, you need to pay attention to the variety.
Test strip or strip test
The strip test is one of the first options for diagnosing pregnancy, a test for independent use and quick interpretation of the results. The most common and cheapest option (for example, Itest Plus is offered at a price of 20 rubles).
A paper-plastic strip with an additional inner layer impregnated with reagents becomes colored in one or two places upon contact with urine. One strip confirms the effectiveness of the test, two indicate the presence of a sufficient concentration of the hormone human chorionic gonadotropin to confirm pregnancy.
Directions for use: collect the first morning urine in a clean container, lower the test to the limit indicated on the strip, hold it in the liquid for the required time (usually 20-30 seconds), remove it and place it on a dry horizontal surface.
Diagnostic results appear within a period of 1 to 10 minutes, depending on the concentration of the hormone. Some tests can also change the degree of color of the control strip - the paler the color, the shorter the gestational age.
Tablet type tests
Tablet tests are based on the same operating principle as strip tests: when a certain part of the surface comes into contact with urine, a chemical reaction of the reagent occurs and hCG hormone. To reduce the likelihood of error, the volume of liquid is dosed, and the contact point is limited by a special window.
According to the instructions, you need to collect urine in the included clean container, then use the pipette from the kit to dispense 4 drops into the small window of the test tablet. The results are evaluated in the following window: depending on the variety, one or two stripes or a minus and a plus appear.
Inkjet tests
This variety is considered one of the most accurate and sensitive, and also does not require additional devices or manipulations. The test strip is placed under stream of urine for 10 seconds (if necessary, you can use a container and immerse the test in urine).
Results are to be assessed at intervals of 1 to 10 minutes, depending on the concentration of the hormone. Unlike the above options, jet tests can be used 5 days before the expected date of menstruation.
Digital pregnancy test
Electronic modification of conventional options. The test evaluates the concentration of the hCG hormone and requires immersion in urine, but the result (depending on the type of test) is displayed either on an electronic mini-display or appears on the computer screen to which the test is connected via a USB port.
This option is considered the most optimal due to the impossibility of distorting the interpretation of the results. However, the sensitivity of digital tests is the same as that of inkjet tests: they can be used 3-4 days before the expected date of menstruation. When tested 2 days before the start of menstruation, 99% accuracy is guaranteed.
Negative test result in developing pregnancy
In most cases, tests show negative result in pregnant women if tests with low sensitivity are used too early, or if instructions for use or storage are not followed. A negative result is also possible due to late ovulation and late conception - in such cases, hormonal levels change more slowly than expected in accordance with the menstrual cycle.
Diseases of the endocrine system and hormonal imbalances also lead to negative test results. The threat of miscarriage is characterized by an increase in the level of the hCG hormone that is inappropriate for the gestational age, which, accordingly, leads to one line on the test at a time when the hCG concentration should be sufficient for two.
It is worth knowing that during pregnancy, tests can only be used in the first trimester. The concentration of hCG is not maintained during the period of waiting for the child, which leads to incidents: if tests are carried out for a period of more than 2-3 months, the result will be negative.
False Positives
Positive test results in non-pregnant women are much less common than the opposite situation and in most cases indicate the presence of diseases (ovarian dysfunction, the formation of a tumor formation in the reproductive organs that produces hormones, etc.). False-positive diagnostic results are also observed in the first two months of the postpartum period and when using an expired test.
Testing during menstruation
In some women, pregnancy is accompanied by menstrual-like discharge, similar in abundance, timing and symptoms to normal menstruation. As a rule, the discharge ends in the first trimester, but there are known cases of its manifestations throughout the entire gestation period. In such situations, it is recommended to resort to diagnosis using a blood test, but the use of tests is also possible.
Any test is based on assessing the concentration of the hormone in the urine and the presence of menstrual fluid in it does not affect the effectiveness of the tests.
If the test results are in doubt
Sometimes it is not easy to interpret the results of express diagnostics: the second indicator strip is slightly marked, visible from the inside of the test. Sometimes this happens due to poor-quality production of cheap paper test strips: when wet, the reagent becomes slightly more noticeable than when dry.
A visible but pale second line most often indicates a low level of hCG, insufficient for the sensitivity of the test. In this case, it is better to postpone the check for 1-2 days or use a more highly sensitive option.
A strip with an insufficient degree of color may also appear as a result of improper storage of the test or violation of the instructions. In any case, repeat testing and/or blood testing for hCG is recommended.
Ectopic or non-developing pregnancy
The test results for an ectopic and/or non-developing pregnancy are also positive: on the days of expected menstruation, the presence of a second line on the test is most often noted. But the hormone level does not increase in such conditions; upon repeated testing, the pregnancy indicator strip may turn pale or not appear, which requires immediate consultation with a doctor.
Pregnancy is an important stage in the life of every woman. The correct definition of this exciting event is equally significant both in the case of a planned conception and its unexpected occurrence. Since it is especially important to determine the fact of fertilization as early as possible, in lately Modern rapid tests are becoming the main means for its initial diagnosis.
How pregnancy tests work
Diagnosis of pregnancy using a test is based on the detection of a special hormone in female urine - human chorionic gonadotropin, the production of which actively begins on the 6th day after fertilization of the egg. When a biomaterial containing hCG comes into contact with the reagent, an indicator coloring reaction occurs, which with a high probability indicates the occurrence of conception.
The level of human chorionic gonadotropin begins to increase from 6-10 days after fertilization. Having reached its peak in the second trimester, its quantity begins to decline.
Dynamics of hCG growth
The reliability of the test and its ability to determine pregnancy at the most early stages directly depends on the level of sensitivity, measured in milli International units per 1 milliliter - mIU/ml. In modern rapid tests, this indicator varies between 10-25 mIU/ml. The lower the specified parameter, the more sensitive the indicator reacts, therefore, it is possible to detect fertilization at the earliest stages (11-12 days from the moment of ovulation). Only a biochemical blood test can provide a more accurate diagnosis, since the concentration of hCG in it increases a little earlier.
The standard test sensitivity of 20-25 mIU/ml, with the maximum degree of reliability, detects an increased level of the hormone already on the 1-2 day of a delay in the menstrual cycle.
Reasons for the unreliability of determining the presence of pregnancy
Despite the high degree of reliability of modern express studies, when determining the presence of pregnancy, false positive or false negative results can often occur. In each individual case, the reasons for the error may be different.
In rare cases, test readings may be incorrect
To reduce the likelihood of errors during diagnosis, it is recommended to repeat the test after 2-4 days.
Reasons why the test found it to be false positive result:
- some diseases and work disorders internal organs and the endocrine system, in particular - ovarian dysfunction;
- taking hCG-based medications 2 weeks before the study;
- an attempt to diagnose pregnancy less than 2 months after childbirth, miscarriage or abortion;
- expiration of the test’s shelf life or non-compliance with storage conditions (violation of the seal of the packaging);
- the presence in the body of tumor formations that produce the hormone human chorionic gonadotropin;
- omission of more than 10 minutes after the start of the diagnosis (for certain types of tests).
Factors influencing the detection of a false negative result:
- an attempt at early diagnosis carried out before the recommended period indicated on the package;
- disruption of the endocrine system;
- decreased hormone levels associated with individual characteristics woman's body;
- violations of the diagnostic procedure;
- expiration date;
- failure to comply with storage conditions or failure to seal the packaging;
- taking certain types of medications the day before the test.
Preparing for the test
All existing types of express tests are based on the principle of detecting the hCG hormone in biomaterial (urine).
Popular types of tests
In order to eliminate possible inaccuracies in determining pregnancy, it is advisable to follow several recommendations:
- use only tests of the appropriate expiration date, packaged in airtight packaging;
- the package must be opened immediately before the test;
- rapid tests are for one-time use only. If for some reason the indicator gave incorrect readings the first time, attempts to diagnose it again do not make sense;
- The highest concentration of the hCG hormone accumulates in the body during the night, so according to the instructions, it is better to take a pregnancy test in the morning;
- It is advisable to wash yourself before urinating;
- collection of biomaterial is carried out in clean containers;
- following the instructions, lower the indicator into the liquid only to the specified level;
- it is necessary to strictly adhere to the diagnostic time;
- compare the diagnostic results with the accompanying instructions for the pregnancy test.
If there is a long delay in the menstrual cycle in conditions where the pregnancy test shows a negative result, a blood test will help to identify the presence of the hCG hormone in the body.
Types of pregnancy tests
Regardless of the level of sensitivity, pregnancy tests also differ in design and method of use:
- strip strips - narrow paper strips impregnated with a reagent containing antibodies to the hormone, are considered the most popular and affordable type of test, which, despite its low cost, is characterized by high diagnostic reliability.
- flatbed - are a modified format of strip strips, enclosed in a plastic block with two windows.
- inkjet - similar to a mini-case, at one end of which there is an indicator that does not require collecting urine in a container, but conducts diagnostics upon contact with biomaterial during urination. The indication is displayed in a separate window.
Jet pregnancy test
- electronic-digital - highly sensitive miniature devices with a simple system for collecting biomaterial, in which the result is displayed on a mini-liquid crystal screen. Certain types of devices are compatible with a PC and allow you to determine the approximate gestational age with a high degree of probability. They are considered one of the most expensive.
Pregnancy test: instructions for use
Since the classification of modern tests is based on the principle of diagnostics, each of the presented types has its own differences and application features.
The cost of the test does not directly affect its reliability.
Strip strips
Since these express tests do not include a special container for collecting biomaterial, it must be prepared in advance. You need to collect a little urine in a clean, dry container and lower a paper strip into it for a few minutes to the mark indicated on its base. You can judge the presence or absence of pregnancy no later than 10 minutes. A positive result is marked in the form of 2 parallel lines, a negative result - one.
Strip pregnancy test
Tablet version
The tablet test kit includes a mini case with an identifier, a special urine container and a pipette. Having collected the required portion of the biomaterial in a container, you need to take a small amount into a pipette, and then apply a few drops to a special window. In no more than 10 minutes, the result in the form of one or two stripes will be reflected in the second window.
Inkjet view
Due to the absence of the need to collect liquid in a separate container, inkjet pregnancy indicators are considered one of the simplest and most convenient to use. To carry out the procedure, simply place it under a stream of urine for 5 seconds. Diagnostics can also be carried out in the standard way by placing the tip in a container with biomaterial. The result will be displayed within 10 minutes (the time depends on the overall hormone level) in the form of one or two stripes. High sensitivity allows you to determine the presence of conception at the earliest stages.
Electronic digital device
The most modern and at the same time expensive way to determine fertilization is to use an electronic verification system. The tip of the filter is briefly immersed in the urine and after 3-4 minutes the result is displayed on the liquid crystal display. This type is considered the most accurate, effective and convenient, but the inscription disappears within a day.
Diagnosis of abnormalities using a rapid test
A simple pregnancy test system can detect not only the fact of fertilization, but also various problems and pathologies.
Promotion hCG level can occur not only during conception, but also in non-pregnant women, as well as in men. Such a deviation may indicate a number of serious diseases. Among them:
- tumor formations in the testicles in men;
- pathologies associated with tumor formation in the gastrointestinal tract;
- malignant and benign tumors in the respiratory and genitourinary systems;
- molar pregnancy or hydatidiform mole;
- malignant trophoblastic tumor.
Increased hCG levels are also possible in men
Tests in which the second stripe is clearly paler than the first also deserve special attention. This indicator may indicate a reduced level of the hormone human chorionic gonadotropin. This condition is possible in the early stages of conception or in cases of frozen pregnancy.
If you have any doubts about your health, it is better to immediately consult a specialist.
After conception, the woman’s body gradually increases in blood pressure, which produces trophoblast cells - these are the precursors for the formation of the placenta. Thanks to its presence in urine, early diagnosis of pregnancy can be carried out.
The test can be carried out already after the second day of missed period.
But many women who are faced with this issue for the first time do not know how to choose such a product, how to use a pregnancy test and how to avoid mistakes?
Mechanism of action
The standard test that determines the presence of human chorionic gonadotropin in the urine has two strips - control and diagnostic.
The first one works if any moisture gets on the surface.
A diagnostic strip has special substances (antibodies) that react to the presence of hCG in the urine.
During direct contact of human chorionic gonadotropin with labeled antibodies, the diagnostic strip turns red.
Buying a pregnancy test
Buy tests only in pharmacies. This will help you avoid purchasing a low-quality fake.
When purchasing a pregnancy test, check the integrity of the packaging. The strip should be packed in thick cellophane. Sometimes it is filled with air.
If the product's expiration date has expired or you find damage to the packaging, then there is no point in doing such a test - the result will be unreliable.
When studying a wide range of pregnancy tests, you see products from different companies and different price ranges. But the reliability of the result does not depend on the manufacturer and cost. Is it true, more expensive tests respond even to the lowest dose of human chorionic gonadotropin.
That's why, if you can't wait to find out the answer to a question whether you are pregnant or not, but only a couple of days have passed since your missed period, give preference to a sensitive test. Thanks to him, the situation will certainly become clearer.
When to take a pregnancy test?
If you want to achieve maximum accuracy in diagnostics at home, do not eat in the evening before using the test fatty foods and refuse sexual contact.
It is advisable to use the test strip in the morning, taking the first urine of the day for research.
Do your research only before meals. After eating, the answer will be untrue.
It is at the beginning of the day that the concentration of the hormone is highest and the result will be the most accurate. Therefore, immediately after waking up, go to the toilet.
Collect the urine in a container and lower the tip of the test strip into the urine to the indicated mark, holding it there for a couple of seconds. After this, place the test on a horizontal surface.
The result will be ready in 5 minutes. After 10 minutes the test is considered void.
Two stripes indicate that conception has occurred. But it is worth considering that a positive result can also occur in the absence of pregnancy. This mainly occurs due to hormonal imbalance in the body.
To find out exact result, it is better to go to a gynecologist after the test, who, after examining the uterus, will be able to determine whether pregnancy has occurred.
Sometimes in the early stages, if the gynecological examination was not indicative, an ultrasound examination or tests are prescribed.
But even if the second line appears faint and barely noticeable on your test, most likely you are pregnant. You can additionally use a couple more tests from other manufacturers.
Remember, in some cases, hormone production begins not on the 6th day after conception, as usual, but on 14-15.
This is the period of maximum concentration of human chorionic gonadotropin. Therefore, if the test result is negative and there is no period, there is a reason to wait a few more days and repeat the study, which next time, perhaps, will tell you the long-awaited answer.
Types of tests
- Strip strip– the most common type of pregnancy test. This is a thin strip with a reagent inside. Using this test, human chorionic gonadotropin is determined in the urine. Open the package immediately before use.
- Tablet test is an analogue of laboratory pregnancy diagnostics adapted to home conditions. It gives the most accurate result. It differs from test strips in that it does not need to be immersed in a container with urine and this product is more reliable because it is protected in a plastic box. You should take a portion of urine into a disposable pipette and insert 4 drops into the special window of the test cassette where the reagent is applied.
- Electronic test. The method of application is identical to the tablet and conventional tests. But in this case, under the influence of human chorionic gonadotropin, not a colored stripe will appear, but the inscription “pregnant” or “not pregnant.”
- - this is the most reliable method for early detection of pregnancy at home. This product has a more sensitive reagent. This affected its cost, which is higher than the price of tablets and test strips. You can find out about the onset of conception 4 days before the start of menstruation. The jet test is especially convenient because you do not need a container to collect urine.
Remove the cap from the cassette and grab the test in the place where there is a mark in the form of an arrow. You need to place the marked tip, which was under the protective cap, under a stream of urine for a few seconds and then close the test with the cap.
The result according to the standard will be ready in 5 minutes and will become invalid after 10 minutes.
The study can be carried out at any time of the day, because a very sensitive reagent detects the presence of human chorionic gonadotropin, regardless of its concentration level. But follow the instructions as precisely as possible, otherwise the result may be false.
False positive pregnancy test result
False positive result- this is the case when the test shows 2 stripes in the absence of pregnancy.
In low-quality tests this can happen: that the dye will split off from the conjugate before the entire antibody-hCG-dye complex reaches the reaction zones.
This is how blurry spots appear. This result is often mistaken for a “false positive”. But true false positives are extremely rare.
Besides, a faint second stripe appears, if the test is “overexposed”, that is, study the readings after 10 or more minutes.
A similar line is formed due to the evaporation of water from the surface of the dough. This destroys the conjugates, which release the dye.
Precisely because not every woman strictly follows the instructions and incorrectly interprets the test result, doctors, especially old-school gynecologists, do not have too much faith in early diagnosis of pregnancy carried out at home.
A false positive response can be caused by taking specific medications, kidney problems, or drinking too much fluid.
Sometimes this result indicates about the presence of a trophoblastic tumor. Some gynecological diseases can provoke increase in the level of human chorionic gonadotropin and in order to exclude them, it is necessary to contact a gynecologist after a positive test result.
If you were given hCG to maintain the luteal phase(preparations Pregnil or Profasi), then traces of this hormone remain in the body for 10 days after the last dose of the medication. Therefore, a pregnancy test in such cases gives a false positive result.
False negative test
There are times when tests give false negative. This occurs much more often than cases with a false positive result.
A false negative test is typical for conducting the test too early. or for a low sensitivity test.
During a pregnancy that is on the verge of, human chorionic gonadotropin will not be produced as intensively as during a normally developing pregnancy.
Anyway a pregnancy test allows women not to run to the doctor at the slightest delay, but first check at home and only then consult a doctor to clarify the results.
It is after this that we can clearly speak about the presence or absence of pregnancy.
Some passionately dream of having a child, while others realize with horror that an accidental mistake in the form of unprotected sexual intercourse can radically change their lives. Can help get rid of doubts early pregnancy test . The principle of operation of all products presented on pharmacy shelves is almost the same: they allow you to find out whether conception has occurred or not even before visiting a doctor. However, for the results to be correct, it is worth knowing the principle of operation of the product and how to carry it out correctly.
Read in this article
How does the test determine pregnancy?
The best early pregnancy tests have increased sensitivity. Manufacturers use high-quality materials, so products cannot be too cheap.
The main principle of action: due to the content of a unique substance on the strip that will interact with urine, the level of the hCG hormone is established. If conception has taken place, then the production of human chorionic gonadotropin increases even before the delay, which gives rise to the appearance of two stripes.
It is worth noting that the results will be correct starting from 7-10 days after sex and provided that it coincides with the time of ovulation. After all, it is then that the fertilized egg attaches to the wall of the uterus. HCG begins to increase from this moment, increasing gradually every two days. Doctors also note that the maximum concentration of the hormone is observed on days 8-10, after which its level will decrease slightly. If a woman multiple pregnancy, then hCG will increase in proportion to the number of fetuses. It is worth noting that if there are problems (ectopic implantation of the fetus, threat of miscarriage), the hormone will be lowered.
How and when to test to get an accurate result
Previously, an early pregnancy test was carried out exclusively using morning urine. Reliable data could be obtained without leaving home. Now actively selling earliest pregnancy test , which is called jet. It allows you to conduct research at any time of the day.
And yet, doctors recommend not to rush to find out the result, but to wait for your period. If the delay is more than three days, do an analysis. If you are still tormented by doubts, then how to determine early pregnancy The gynecologist knows for sure. He will examine the condition of the discharge, and also, with the help of additional tests, will accurately determine whether it has happened. long-awaited event or not.
Can the test show incorrect data?
Sometimes it happens that a girl has everything, but the test is negative . Usually this is encountered by those who really want to quickly find out what is under the heart of a child. From the first days of the delay, or even immediately after sex, they begin to feel all the main symptoms: the nipples became very sensitive, the pain increased, and vomiting began in the morning. If these symptoms occur separately, then it is too early to talk about conception. For example, nausea and vomiting may indicate problems with the gastrointestinal tract. As for the delay, it also occurs due to inflammation of the appendages.
The test is negative, but there is confidence in conception
If you are sure that negative pregnancy test - nothing more than a mistake, visit a gynecologist. The doctor will be able to accurately determine whether it was possible to conceive a child. At a very early stage, for an accurate diagnosis of the condition, Ultrasound to determine pregnancy and a urine test for hCG hormone levels. Usually they guess about their interesting situation even before all the diagnostic methods confirm it for women who are not already pregnant for the first time.
If you're wondering why doesn't the test show? long-awaited two flats, then either you spent it very early, incorrectly, or it is expired or of poor quality, or while you are wishful thinking. Erroneous readings can also occur if a woman has an irregular cycle, and she wants to see the result much earlier than the embryo has time to consolidate. It is recommended that if you have an irregular cycle, use the express method only after your menstruation has been delayed for more than a week.
Unfortunately, there are more unpleasant reasons why pregnancy test before delay and after it it will stubbornly show a negative result, even though it was possible to conceive. The following can affect the erroneous indicator of the hCG hormone:
- threat of failure, or;
- the presence of pathology and chronic diseases of the cardiovascular system and kidneys.
The accuracy of the diagnosis can also be changed if diuretics were taken or a lot of liquid was drunk before the test. Wait a few days and test again. Or immediately visit a gynecologist to get a 100% accurate answer about your condition.
False positive test
Although the manufacturers claim that early pregnancy test accuracy is 99%, sometimes it turns out to be false positive. This situation occurs for various reasons, the main one of which is a violation of the amount of the hCG hormone under the influence of certain factors. These include:
- oncological diseases;
- the state of the body after spontaneous abortion or miscarriage;
- when taking medications used to treat infertility;
- others.
In the presence of cancer, even in men, a test showing pregnancy in the early stages will be positive! If you are absolutely sure that the baby could not have been conceived this month, first rule out all the factors that give a false result, and then conduct the examination again or consult a doctor.
Weak positive test
It happens that express early pregnancy test will show one clear and second blurred stripe. This can happen if the product was not stored correctly (for example, without protective packaging) or if it has expired. We can also consider the situation when the test is positive, but there are no signs of pregnancy as a sign of conception. However, it has not yet been accurately identified because too little time has passed.
How to properly conduct a rapid examination
The reliability of the results will also be influenced by external factors. To find out for sure whether it’s time to prepare to become a mother, you need to take the following steps:
- Inspect the packaging for damage.
- Check the expiration date of the product.
- Prepare a clean container and create conditions as close to sterile as possible.
- It is better to use morning urine, but if you have not had your period for a long time, then any time of day will do.
- Wash and dry your hands before starting the test.
- Take out the test strip and lower it to the indicated level.
- Place it on a dry towel or napkin.
- The result can be seen in one to three minutes.
Types of tests, their pros and cons
In a pharmacy, it’s quite easy to get lost among the offered product options. For clarity, all the positive and negative aspects of using various tests are collected in a table:
| Type of test | Positive characteristics | Disadvantages of use |
| Test strips (strip tests) - fabric or paper products, the surface of which is impregnated with a reagent |
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| Plate tests are plastic boxes that contain test strips. Using the pipette included in the kit, a drop of urine is applied to one window, and the result is displayed in the second. |
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| Inkjet tests are modern products that look like a writing pen. It is based on a complex device with a fibrous rod, which is formed from tubules (through which the liquid rises to the part with the reagents). |
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| Electronic tests - analogous to conventional strip strips |
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When choosing among the entire assortment at the pharmacy, you should not settle on the cheapest option. The likelihood of obtaining an accurate result with such a product is low, since manufacturers save on important reagents. If the test shows two lines, but there are no other signs and conception is unlikely, this is a reason to consult a doctor and get examined. Indeed, in such a situation, pregnancy with pathologies and serious diseases that pose a threat to the health of the mother and child are possible.
You should understand how they work, what types there are, and distinctive features. First of all, it is necessary to distinguish between two main types of pregnancy tests - highly sensitive and moderately sensitive. The sensitivity of the test can be read in the instructions for use, in which it is indicated by numbers. So, if the instructions indicate that the test is capable of determining the concentration of human chorionic gonadotropin in urine at 20 - 25 IU/l, then it has average sensitivity. Tests with high sensitivity include systems capable of detecting the presence of human chorionic gonadotropin in urine, starting with a concentration of 10 IU/l.
Highly sensitive tests are most often inkjet or tablet and represent the latest generation of rapid pregnancy detection systems. Sensitive tests can detect the presence of pregnancy starting from the 7th day from the moment of conception. That is, highly sensitive tests can be used even before a missed period, if a full week has already passed after unprotected sexual intercourse. Manufacturers of such highly sensitive tests indicate in the instructions for use that they can be done 1 to 3 days before the date of expected menstruation. However, to obtain accurate, correct and reliable results, it is recommended to wait until your menstruation is late, and then take a test literally the next day. Practical gynecologists and scientists recommend doing a highly sensitive pregnancy test, not relying on the date of the next or last menstruation, but simply counting 7 - 10 days from the moment of unprotected sexual intercourse. If you take a test on the 7th day after sexual intercourse, it may make a mistake and show a negative result during pregnancy in approximately 8% of cases. Therefore, it is better to do a highly sensitive test on the 10th day after sexual intercourse, since after this period of time the accuracy of the study is already 99%.
Moderately sensitive tests can detect pregnancy from the third week of gestation, that is, starting from the 15th day after unprotected intercourse. Tests with an average sensitivity of 20 - 25 IU/l are ordinary and familiar paper strips and some tablet options. In the instructions for use of medium-sensitive tests, manufacturers indicate that they can be used from the first day of the delay. However, such a test will show the presence of pregnancy on the first day of a missed period if conception occurred exactly in the middle of the cycle, that is, when two full weeks have passed before the onset of menstruation. If unprotected sexual intercourse took place 2 - 3 days before the start of the next menstruation, then a medium-sensitive test will not detect pregnancy on the first day of the delay, since at least two weeks have not yet passed from the moment of conception. That is why practical gynecologists and scientists recommend doing a pregnancy test with a sensitivity of 20 - 25 IU/l, not focusing on a delay in menstruation, but simply counting 15 days from the date of unprotected sexual intercourse.
If a woman does not want to count the days from the date of unprotected intercourse in order to find out exactly when she should take a pregnancy test, she can use the following simple recommendations from practicing gynecologists:
- A test with high sensitivity of 10 IU/l should be done from 2 to 3 days of missed menstruation;
- A test with an average sensitivity of 20 - 25 IU/l should be done after 2 weeks of missed menstruation.
