Basic rules for knowing when to do a pregnancy test

Each woman, while in the planning stage of pregnancy, often asks herself the question: "When to do the test?".The correctness of the results depends on the correct timing of the self-diagnosis.

In order to eliminate the error, one should understand some of the basic concepts associated with early pregnancy determination.

Principle of operation of the

device The home tests are designed in such a way that the concentration of a pregnancy hormone called human chorionic gonadotropin( hereinafter referred to as hCG) in the urine of a pregnant woman is determined. This hormone produces cells of the future placenta immediately after the introduction of the fetal egg into the wall of the uterus - implantation.

It is considered that in the blood the quantitative index of hCG on the day of implantation is 2 mIU / ml and is doubled approximately every 2 days. In the urine, the hormone is excreted a few days later, so its concentration will be lower. Most of the tests for home diagnostics have a sensitivity of 25 mIU / mL.Consider when such an instrument will be able to determine the hormone of pregnancy.

It is generally believed that implantation occurs on average 7 days after ovulation. By simple mathematical calculations, it turns out that on day 7 after implantation, hCG is 2 mIU / ml. At day 9, the concentration will be 4 mIU / ml. At 11 - again doubled and equal to 8 mIU / ml. At 13, it went up to 16 mIU / ml, and on day 15( the first day of menstruation delay), the hCG level reached 32 mIU / ml. It is on the first day of delay of monthly gonadotropin concentration that the threshold of sensitivity of a home pregnancy test for the first time will cross, which will show a positive result.

It should be noted that the classical situation is considered in the calculation, when the cycle length is 28 days, ovulation occurred on day 14 of the cycle, and implantation of the fetal egg - on day 7 after ovulation. But the organism of every woman is individual. The results of testing may be affected by late ovulation and implantation. Therefore, many manufacturers recommend conducting diagnostics only after the onset of a delay. In addition, there are recommendations to start testing immediately after waking up, because it is at this time the concentration of hCG in the urine is maximal.

After the answer to the question "When to make a test?" Is found, it is necessary to determine which test is right for you.

Types of tests

The modern medical technology industry offers a wide variety of different pregnancy tests, as the simplest test strips with a sensitivity of 25 mIU / ml, to highly sensitive cassettes with a threshold of hCG determination of 10 mIU / ml.

The latter can determine pregnancy 3-4 days before the delay of the expected menstruation and are more expensive than usual tests. Therefore, if you are impatient to know beforehand whether a conception has occurred, you should make a device for early detection of pregnancy. This can be both a hypersensitive home test and a diagnosis of blood in the laboratory. The latter method is the most reliable and allows you to exclude the error.

Controversial situations in determining early pregnancy

There are situations when it is absolutely unexpected to buy a test. For example, in some women, menstrual bleeding occurs at the onset of pregnancy, as a result of which a woman thinks, then conception did not happen. It should be noted that in this case, menstruation is less intense and prolonged and causes doubts. Therefore, it is worthwhile to conduct a test after menstruation, which are different from usual ones. If you get a positive result, you need to contact your doctor gynecologist to avoid the threat of termination of pregnancy.

It happens that tests show dubious results, when you need to do a pregnancy test again. This happens for several reasons:

• was diagnosed too early;
• used inadequate quality tests;
• violated the rules of the diagnostic, specified in the instructions;
• presence in a woman of diseases that increase the concentration of hCG.

In all these cases, it is recommended that you buy a new test for early detection of pregnancy and carry out a diagnosis after a delay with observance of all rules. It is better to choose tests from different manufacturers.

In conclusion, it must be said that devices for self-determination of pregnancy have become an ordinary subject for a modern woman. But, like any thing, even the simplest, they require competent use.