Every day thousands of women in the world are tested for a home pregnancy which can be bought in pharmacies, usually with the appearance of a few lines, after detecting urine, whether we are pregnant or not. But how do pregnancy tests work? To what extent are they reliable?
The operation of the pregnancy test is very simple. Although externally there are differences, inside these sticks, one end of which must be impregnated in urine, there is a reactive absorbent strip that detects the presence of hormone called chorionic gonadotropin in the urine
We must keep in mind that urine pregnancy tests will only be positive when there is a sufficient level of hGC in the blood, so at the beginning of gestation, a pregnancy test can be negative and yet we are pregnant. In general, with hGC level below 25-50 mLU / mL, the test will be negative.
The level increases if the urine is more concentrated, so you should test the first morning urine. If not, it is enough to wait a few days to perform the test; remember that it is recommended to do the test when there is a delay in menstruation for regular cycles, so that the hormone levels of pregnancy have increased and to be detected by the test.
In general, urine tests require 20 to 100 mIU/mL of concentration of the hormone of pregnancy to give positive. Blood tests detect the hormone at much lower concentrations, so they are more reliable even before the first menstrual period.
The pharmacy tests have a reliability of between 75 and 97 percent if the result is negative, while if the result is positive, the reliability is greater. Remember that a urine test can give us false positives or false negatives as well.
To conduct the test, remove the cap that protects the strip and impregnate it in urine. It is recommended to wet it directly when urinating for a few seconds and then cover it again without coming in contact with any other substance, and wait for a few minutes leaving it on a flat surface.
After three to five minutes, we can read the result, which will be indicated in a different way according to each brand. That’s why you should read the instructions in each case. The most common is that in a little window of the stick appear two lines to give a positive. In addition, there are also digital pregnancy test devices that give us a more complete reading, being able to even indicate the week of pregnancy if it is a positive result. You can now buy online Walgreens digital pregnancy test as well which is more convenient and reliable way.