The principle of the pregnancy test.

At the choice of the buyer, pharmacy chains present a lot of different diagnostic devices for early detection of pregnancy. The so-called strip strips are very popular. They are easy to use and reasonably priced.

Inkjet, tablet tests are more expensive, but they are considered more reliable. Be that as it may, the test shows pregnancy only at a certain concentration of human chorionic gonadotropin (a specific hormone) in the urine. It occurs immediately after the implantation (introduction) of the embryo into the endometrium (inner layer of the uterus). Initially, it rises in the blood and only after a few days is found in the urine. You can reliably find out about the conception that has taken place before the delay only by a blood test for hCG.

If you take a pregnancy test (before or after the delay, it doesn’t matter), then the reagent on the device will start looking for hCG. When a hormone is detected, the device will show its effect. In most tests, this is expressed as a second strip. The first band that appears indicates the correctness of the testing, it is a control one.

Equally important is the sensitivity of the device. Most tests have a range of 20-25 mIU. That is, they will determine pregnancy when there is such a level of hCG in the urine and not before. Tests with a sensitivity of 10 mIU are positioned more accurately.

However, they have a large error and can often give a false positive result. Electronic devices, according to manufacturers, are able to show an accurate result as early as 10 days after ovulation. However, some of them determine the period with an accuracy of up to a week.

The principle is to determine not only the presence, but also the level of hCG, because the longer the period, the more of that hormone in the blood and urine.

What is the most reliable rapid test?

Usually, tests from well-known companies and proper diagnostics give correct results. Errors for the most part are not related to their quality, but to various difficult-to-measure circumstances. For example, a false positive result may result from taking hormonal drugs during the test or due to some health problems in a woman, against which the synthesis of hCG in the body may increase. It also happens vice versa. For example, due to kidney disease, the level of hCG in the urine may decrease, and the result will be a false negative.

Remember that only a qualified specialist can accurately confirm or deny the presence of your pregnancy. After receiving the test results, it is recommended to consult a gynecologist.

How is a rapid test different from a laboratory blood test?

The home test provides a fairly high accuracy. But he only gives a yes or no answer to the question of whether the production of hCG in the body of a woman has increased. The test confirms that the pregnancy has come, but does not show its term - because it does not determine how much the hormone level has increased. Laboratory diagnostics of blood is more accurate. A blood test quantifies the concentration of hCG, which allows you to determine approximately how many days the pregnancy lasts.

It is possible to clarify whether there is a pregnancy and determine its duration during an ultrasound scan. With the help of ultrasound, a 5 mm fetal egg can be detected, approximately at the 4-5th week of pregnancy, immediately after a missed period. Shows ultrasound and some pathologies, in particular ectopic pregnancy.

It is important to understand that ultrasound does not always give an accurate answer to the question of whether you are pregnant. With a low resolution of the equipment at the 3-4th week of pregnancy, the fetal egg can not be seen. Therefore, doctors recommend doing an ultrasound scan no earlier than 6-7 weeks of pregnancy. At this time, you can see the fetal egg and embryo, and hear its heartbeat.

Can a pregnancy test be wrong?

The tests are quite reliable, although they are inferior to laboratory blood tests in terms of diagnostic accuracy. However, a pregnancy test can be wrong. Most often this happens when the rules for its implementation are not followed.

Here is a list of the most common home pregnancy test mistakes:

• It was made in the evening.

It is best to do a pregnancy test in the morning, immediately after waking up - especially in the first days after a missed period. In the early afternoon, the concentration of hCG may not be sufficient for an accurate diagnosis.

• The test was taken too early.

Sometimes women take the test a week after unprotected sex, or even earlier. Alas, it's completely pointless. It takes time for the hCG level to rise and the test to be able to recognize it.

• Drinking plenty of fluids before the test.

The concentration of hCG in a certain volume of urine drops, and the test cannot recognize the pregnancy hormone.

• The test is overdue.

All express tests must indicate the expiration date. If the test is overdue, it will not be able to correctly diagnose the onset of pregnancy and will show a negative result if there is a sufficient level of hCG.

It is important to understand that the test may show an incorrect result, even if you did everything right. Only a doctor can accurately confirm the presence of pregnancy.

What types of tests are available and how do they differ?

Pregnancy tests differ in design and principle of use, which also affects their price. See what options are available to you.

Strip test (test strip).

Usage: collect urine in a container, place the strip strictly up to the specified level, hold for a certain number of seconds.

Price: low.

Disadvantages: the scheme of use, which you need to understand, errors are possible even with a slight deviation from the instructions.

Advantages: economical option.

Test cassette.

Usage: draw urine into a pipette, drop a few drops into the window on the cassette.

Price: average.

Disadvantages: the usage pattern that you need to understand is not the lowest cost.

Benefits: Compared to a test strip, there is less chance that the test will be done incorrectly.

Jet test.

Usage: Substitute the test under a stream of urine.

Price: average.

Cons: Not the cheapest.

Advantages: easy to use, high accuracy.

Digital test.

Usage: Substitute the test under a stream of urine.

The price is high.

Cons: The most expensive option.

Advantages: easy to use, high accuracy. Shows the result not in the form of stripes, but in text (“Pregnant”, “Not pregnant”). Some models have a countdown to display the result, show the week of pregnancy.

On what day after the delay will the test show pregnancy?

You will find exact information about this in the instructions for the purchased express test. In most cases, they are sensitive to a certain concentration of hCG - above 25 mIU / ml. This level of the hormone in the urine is determined already on the first day of delay. After a few days, the concentration of hCG will increase significantly, and the test will be much more accurate in diagnosing pregnancy.

  There are rapid tests that determine pregnancy at an earlier date. They are sensitive to hCG at a concentration of 10 mIU / ml. Such tests can be used to diagnose pregnancy 2-3 days before the date on which the critical days were supposed to begin.

Can I take a pregnancy test during the day?

The level of hCG varies throughout the day, reaching a minimum concentration in the afternoon. After a few days of delay, this will not matter, but in the early days, the concentration of the hormone in the afternoon may not be sufficient to diagnose pregnancy.

Experts advise to conduct a home express test in the morning, when the hCG level is maximum. To reduce the chance of error, you should not drink a lot of liquid before the diagnosis. The test will show pregnancy during the day, but in the early stages, the strip may be too weak, slightly noticeable. In order to be sure, it is better to follow the rules.

In how many days will the test show pregnancy?

It will start working no earlier than the fetal egg attaches to the wall of the uterus, and the production of hCG will increase. It takes 6-8 days from fertilization of the egg to implantation of the embryo. A few more days are required for the concentration of hCG to become sufficient to be able to “color” the second strip of the test.

Most tests show pregnancy 14 days after conception, that is, starting from the first day of a missed period. Some highly sensitive systems react to hCG in the urine earlier and give a response as early as 1-3 days before the expected period. But the probability of error in such a short period of time is very high. Therefore, it is recommended to conduct a pregnancy test no earlier than the first day of the expected menstruation delay or approximately two weeks from the expected day of conception.

Many women are wondering what day pregnancy occurs, and is it possible to do a test in the first phase of the cycle? It's useless. Even if intimacy happened, for example, on the 7-8th day of the cycle, pregnancy will not occur immediately, but only at the time of ovulation - when the egg is released from the ovary. As a rule, this happens in the middle of the cycle - on the 12-14th day. Spermatozoa can live in the fallopian tubes for up to 7 days. They wait for an egg to fertilize it after ovulation. So it turns out that even if sexual intercourse was on the 7th-8th day of the cycle, pregnancy actually occurs only on the 12th-14th day, and it will be possible to determine hCG in the urine using a test only at standard times - on the day the expected menstruation is delayed or a little earlier.

How does a rapid pregnancy test work?

The rapid test determines the concentration of the pregnancy-specific hormone human chorionic gonadotropin (hCG) in a woman's body. Its concentration increases after the conception of a child and becomes clinically significant from the 8-10th day after fertilization. The hCG level rises during the first trimester, reaching a maximum by 12-14 weeks. The more time has passed since conception, the easier it is to detect.

An express pregnancy test works on the same principle as a blood test for hCG. The only difference is that you don't have to donate blood. The test detects human chorionic gonadotropin in a woman's urine. There are two strips "hidden" in it. The first is always visible, the second - only if the woman is pregnant. The second strip contains an indicator that reacts with hCG. If a reaction has occurred, the strip becomes visible. If not, it remains invisible. No magic, just science.

Thus, interpreting the test results is very simple: one strip - no pregnancy, two strips - there is a pregnancy.

Low water during pregnancy is a dangerous condition for the health of the baby and mother.

Oligohydramnios during pregnancy is a rare occurrence in obstetric practice, there are no more than four cases out of a thousand women in labor. A symptom of pathology is an insufficient amount of amniotic fluid. Normally, amniotic fluid before childbirth should be at least 500 ml, which is enough to support the life of the fetus. If the amount of amniotic fluid is less than specified, this is a threat to the woman in labor and the fetus. Consider the causes of the appearance of pathology: how to prevent it, how to convey and give birth to a healthy child.

The amniotic fluid plays a key role in the development of the baby, as it protects and provides nutrition. Low water during pregnancy is a dangerous condition for the health of the baby and mother. Amniotic fluid contributes to the rapid opening of the cervix during childbirth, without which self-delivery is impossible. Amniotic fluid protects the fetus from being squeezed by the walls of the uterus, which can cause severe deformation of the skeleton and even dislocation of the limbs. Therefore, monitoring an acceptable level of amniotic fluid is an important task for the obstetrician and the expectant mother.

In order to prevent the development of pathology, you need to follow the recommendations of the gynecologist, observe the daily routine, eat well, eliminate stress and bad habits. A pregnant woman should know that worries and experiences negatively affect her own health, as well as the well-being of the baby. Preventive measures, reading useful literature, a healthy lifestyle are the path to successful childbirth and the postpartum period.