How pregnancy tests work.

The presence of pregnancy is established by detecting the hormone hCG (chorionic gonadotropin), produced in the body of a woman after the embryo is attached to the uterus. This hormone is produced to block the natural function of the ovaries and prevent re-pregnancy.

In the early stages, the female body produces this hormone in small quantities, so the test is recommended to be done no earlier than a few days from the day of the delay.

There are frequent cases when a woman does not know the exact date of the onset of menstruation due to their irregular course, as well as situations when the test gives a negative result, while processes are taking place in the body that in all respects resemble signs of pregnancy.

In such cases, it is recommended to visit specialized institutions for taking a blood test to determine the level of the hCG hormone. In this way, pregnancy can be determined even before the onset of a delay in menstruation, since this hormone enters the bloodstream much faster.

Test strips sold in retail pharmacies often give incorrect results, because they are not very sensitive, but show the result only from a certain amount of the hormone contained in the blood. It enters the blood slowly, so a test made in the first days may show an incorrect negative result, due to the fact that a sufficient amount of the substance has not yet been produced in the body.

In the presence of pregnancy, this number increases daily, therefore, with a negative indicator, it is recommended to repeat the test after a few days. The test strip shows the most accurate result on the 15th day from the day of ovulation, so it is important to know the exact or estimated date from ovulation, which will help you understand when to take the test.

Doctors say that the hormone reaches its maximum at the 8th week of pregnancy and this level lasts until the 12th week, after which it begins to slowly fall. If the pregnancy is multiple, then this figure doubles accordingly. If at 3-6 weeks the level of hCG is less than normal, then this may indicate a likely risk of spontaneous miscarriage of the embryo.

What day of delay do you take a pregnancy test?

Many women, faced with a missed period, do not know when to take a pregnancy test. Some react calmly, for others, this phenomenon causes concern. It can definitely be said for sure that the anticipation of the result and the uncertainty at the moment of waiting make both types of women worry.

In most cases, on the first day of the delay, the test cannot show the exact result. Of course, the task of pregnancy tests is to establish an increase in the level of hCG against the background of the presence or absence of pregnancy in the early stages, but, unfortunately, the test is not always capable of this, due to a number of features.

How does a pregnancy test work?

So, we know that after fertilization, the level of the hCG hormone in the woman’s blood begins to rise, which indicates the presence of pregnancy. Having determined this substance, the test shows us a positive result - two strips. In fact, the test reacts to the presence of the hormone gonadotropin in the urine: when the level of hCG rises, a reagent appears on the second test strip.

HCG in the body of a pregnant woman is produced immediately after the implantation of the embryo into the uterine wall, first in the blood, and a little later in the woman's urine, and usually in the urine it is in a lower concentration than in the blood. Implantation, in turn, occurs 7-10 days after ovulation.

But at the same time, it must be borne in mind that the level of the hormone grows gradually, increasing daily, until it reaches a certain level, which the test is able to fix. This is the moment that sets the time frame.

That is, the test is able to "detect" the presence of the hormone gonadotropin in the urine of a pregnant woman no earlier than 11-15 days after the day of the last ovulation. The lower the sensitivity threshold of the test, the earlier it will be able to determine pregnancy and the more expensive it is.

Tests with a sensitivity of 10mIU / ml (as a rule, inkjet tests belong to this category) are able to determine a pregnancy that has taken place several (up to five) days before the expected period.

Tests with a sensitivity of 25 mIU / ml (in the form of strip strips) determine pregnancy from the first day of delay. But these are statistics. And there are individual cases with early or late implantation. Therefore, a premature test can often be wrong.

The probability of a test error is especially high if a woman has an irregular menstrual cycle. An early test in this case may show false negative results, because the gestational age may be very short for the reactive strip to work. A pregnancy test error is more likely the earlier the test was taken.

A pregnancy test with an irregular cycle does not make sense to carry out before a delay. The earliest time when this can be done is two weeks after ovulation, and the longest cycle should be taken as a guideline.

If you do not monitor this process, then it is recommended to test after a delay, and for greater reliability, it is best to repeat the test again, after a week or two. Regardless of the regularity of the cycle and other features of the female body, the reliability of the test will be the higher, the more clearly the rules for its implementation are observed. Any violation of the instructions may cause false results.

It is believed that in the morning a pregnancy test shows the most reliable results, since the concentration of hCG in morning urine is the highest. But if the delay is already large, then by and large it is possible to conduct a test at any time of the day.

A prerequisite is the observance of the rules of sterility: no foreign substances should enter the test liquid, and therefore the hands must first be thoroughly washed and wiped dry. Also, prepare a sterile collection vessel in advance.

The test strip must be immersed in the container with urine only to the level indicated on its canvas, and always on the side where it is indicated (where the reactive substance is contained).

You should not evaluate the test result earlier than the time indicated in the instructions (usually 5 minutes) or much later. After a long period of time, the results of any test are considered invalid.

When is the best time to take a pregnancy test for an accurate result?

Modern tests allow you to determine pregnancy as soon as possible after a "suspicious" sexual intercourse. But this cannot be done earlier than is possible in principle. And in order to correctly answer the question posed, it is necessary to understand the processes that occur after the meeting of the spermatozoon and the egg.

The test showed a weak second line - why?

Most likely a low hCG level. Exit: wait 3 days and repeat the procedure. The amount of the hormone will increase markedly, and the strip will become brighter.

If at the same time the test has poor sensitivity, it is better to buy another one with a mark of 10 mIU / ml. Buying several products of different brands and batches or taking tests at a antenatal clinic will also help clarify the situation.

What day of the delay to do the test?

If the cycle is regular, then you can buy tests already for 1-3 days of delay. If not, it is better to wait at least another 2-3 days or take the test several times with an interval of three days.

In cases where a woman does everything to get pregnant, she can try to find out the result even a couple of days before the expected menstruation. To do this, she will need an inkjet or electronic test, since other options are not sensitive enough for such a short period.

On the 7th day of delay, in the absence of specific diseases and proper use, any tests will reliably show whether a woman is pregnant or not.

The answer to this question is in the instructions, since each product is individual. As a rule, the waiting time does not exceed 20 minutes. Strips take longer, but inkjet, electronic and tablet wands are faster.

Another criterion is the gestational age. The smaller it is, the longer the result appears. In a test with poor sensitivity, daytime and evening urine may generally give a false negative response.

There is a separate category of test-strip cases that are misleading. The product may not detect pregnancy after the specified period of time. However, after an hour or even a day, a second strip will appear on it. It does not necessarily indicate a successful conception. It is better to play it safe and go through the procedure again or contact a gynecologist.

Inkjet pregnancy test.

It is valued for its accuracy, good response to hCG, ease of use. After removing the cap, the tip is placed under the urine stream. It is recommended that it be tilted down. Often the result appears right in front of your eyes after half a minute. However, to be completely sure, it is better to postpone the test for 3-10 minutes.

Results:

• one strip - not pregnant;

• two stripes - pregnant.

Fertilization of the egg occurs within 12 hours after successful intercourse. However, it is impossible to determine this moment with the help of tests. In addition, it will take a week or more for the embryo to move into the uterus and implant in its wall. As soon as this happens, the production of the hormone gonadotropin will begin. It is he who helps determine pregnancy.

So, hCG appears in the body on average 7-10 days after conception. Then its amount doubles every 2-3 days. In the second or third month of pregnancy, its concentration reaches a maximum.

Accordingly, the test is done no earlier than a week after sex.

Tablet pregnancy test.

Similar to the previous view. The difference lies in the fact that a pipette is attached to the product, and the indicator line is located in the case itself.

A small amount of urine is collected with a pipette. It is better to take it again from the container. Then a few drops from the pipette are left on the indicator located in a small hole on the body. It remains only to wait.

Results:

• one strip - not pregnant;

• two stripes - pregnant.

Its main advantage is that it can show the approximate date of conception. Course of action:

1. remove the cap from the dough. Immediately proceed to the second step;

2. substitute the object under the stream of urine for 5 seconds or lower its tip for 20 seconds into the container with urine;

3. close the cap and place the product on a horizontal surface. You can also hold it in your hands, but make sure that the tip is pointing down, not up;

4. wait until the final image appears on the screen.

Results:

• “not pregnant”, “no” or “-” – no pregnancy;

• “pregnant”, “yes” or “+” and numbers indicate pregnancy and approximate period since embryo implantation.

Pregnancy test - when to do?

Morning urine is considered optimal for delivery - it is the most concentrated. Therefore, it is better to do tests immediately after waking up, or at least before eating and drinking any drinks, including plain water. However, inkjet tests are highly sensitive to hCG, so they can recognize it even in daytime or evening urine.

In individual cases, you can take an analysis regardless of the time of day. He is more likely to reveal the truth if the woman at that moment feels:

• pain in the chest and/or nipples;

• spasms and/or pulling pain in the lower abdomen;

• nausea, weakness, dizziness;

• sudden strong desire to eat something specific.

These symptoms indicate an active change in the hormonal background. A test that “caught” such a moment will surely show the truth.

• Make sure that your hands are clean and dry before the procedure.

• Check the expiration date of the test.

• Buy products only in pharmacies.

• Adhere to the rules of storage and use described in the instructions of the purchased product.

• Keep the area where the test will be kept clean while the results are showing.

They are the cheapest and easiest to use. To begin with, morning urine is collected in a dry, clean container. It is desirable that it be small, but with high walls. The strip is dipped into the liquid to the indicated mark for 20 seconds. After that, it is better to put the test on a flat horizontal plane and wait a few minutes.

Results:

• one strip - not pregnant;

• two stripes - pregnant.

When can I take a pregnancy test and how to do it correctly?

If the cycle is regular, there is no point in doing a test before the start of the delay. With each passing day, the reliability of the results will increase. However, it is better not to wait weeks or even months. In the first weeks of pregnancy, it will be easier for the doctor to help the mother and her unborn child avoid dangers.

If the menstrual periods are unstable, you will have to wait a period of time equivalent to the longest cycle of the year. For example, if it lasted 34 days, then it is better to count the same number of days from the beginning of the last menstruation, and then only buy a test. Do you know the day of ovulation? 2 weeks after it, it will already be possible to find out about your situation.

The situation largely depends on the type of test. For example, a jet with a mark of 10 mIU / ml is able to determine a successful conception even 3 days before the expected menstruation. And devices labeled 25 mIU/mL will be useless until the delay begins.

HCG is a hormone whose presence indicates pregnancy. It becomes noticeable in the blood faster and better than in the urine. Therefore, a laboratory test shows a result earlier than most pharmacy ones.

Is the expected day of conception known? You can donate blood for analysis within a week after this date. If not, then the first day of the delay will be the best reason to go to the antenatal clinic.

If the test results are indeterminate, the gynecologist will recommend that you donate blood again after a few days. Want to know the answer for sure and the first time? Then it is advisable to donate blood for hCG approximately on the 3rd day of the delay. At this time, his concentration will become clearly noticeable.