Express tests of the definition of pregnancy in the post-Soviet space became especially popular about 15 years ago. At the dawn of their "success" they cost a lot of money and they could not be found in every pharmacy. Whether it's now - they are at the ticket offices in supermarkets,they can be purchased at any pharmacy and even a cosmetic store.
The mechanism of all rapid tests of pregnancy determination is the same.
It is based on the identification in the urine of a woman's chorionic gonadotropin. It is a hormone that is produced by the structures of the embryo after it is attached to the uterus or the fallopian tube. Normally this hormone does not exceed 5 international units per ml. But already on 7 - 10 day after conception the level of hCG reaches 25 !!! Mme / ml. The test surface of the test is coated with a special reagent: it consists of antibodies to HCV. If a woman is waiting for a baby, then these antibodies, upon contact with the urine, react with hCG, showing two strips. Chorionic gonadotropin is produced in the blood of a future mummy, and then - is excreted through the kidneys, but because the tests are equally effective both for the definition of normal and abnormal - ectopic - pregnancy. The test strips used by most women "testing" themselves for pregnancy are usually placed for a few seconds in a clean container from the urine to the level outlined on it, then they are extracted and after some time the result is evaluated . The result is manifested within 5-7 minutes. Further, the reagent loses its force and ceases to function. This test is best done in the morning - when in urine the highest concentration of chorionic gonadotropin.
The minimum error rate is possible in more advanced tests - tablet. To conduct such a test, you just need to drop urine. But it's not easy to find tablet systems, so they are not very popular yet. In contrast, for example, from test-systems. The latter are very simple in research, they do not need to search for additional containers: it is substituted directly under the urine stream, you can carry out such at any time of the day. And the result is actually one hundred percent.
Of course, tests can be wrong. But, as a rule, in most cases the responsibility for the error rests with the "tested" one. In particular, on how correctly she did everything, did not violate the instruction, whether there was water instead of urine in the test system.
Tests can be wrong and if they are substandard. But do not think that the more expensive it is, the better. This is completely wrong. The quality of the test depends on the manufacturer. According to the surveys, the greatest "errors" are given by tests of the firms "Vera", "Eva-test", "Mon Ami", "Frau-test". Errors and "I-test", "Bee-Sure".
The test that has expired is also not going to give you the right result, so it's good to see if the integrity of the package is broken.
If the time has not passed after the alleged conception, the test is also mistaken. He will not show the correct result of a pregnant woman with kidney pathology or hormonal imbalance. But if the test gives a false-positive response, then this may indicate the presence of tumor diseases - and, in any place.
Depends on the test result for determining pregnancy and on the method of applying antibodies to the test strip, and on the quality of the reagents, and on the storage conditions.
On average, the reliability of the tests on the first day of the delay of 90% 5%. After a week, the absence of menstruation is higher - 94-100% with proper use.
In any case, do not forget - nothing is insured against errors, so it will not be a problem if you run the test again to make sure the result is correct. But you should not rely on the test alone. What would not be the statistics, and "yes" or "no" to your alleged pregnancy can only be told by the doctor - after