Modern tests for the determination of pregnancy inState to inform a woman about the interesting situation that has come about almost from the first day of the delay of menstrual bleeding. Nevertheless, they do not give an absolute guarantee, it can happen for several reasons.
Today's market for pregnancy tests atThe first look is very diverse, but if you look closely, you can see that they all work on the same principle. Introduced in the endometrium, a fertilized egg contributes to the production of a specific hormone, human human chorionic gonadotropin, abbreviated as hCG. Since the first days of pregnancy, it is present in the blood of a woman, in a slightly lower concentration in the urine and the amount of it increases day by day. And the cheapest test strip, and steep electronic tests - they all work on the same principle: they contain a special substance that reacts to hCG staining in red or blue. Their accuracy is quite high. Nevertheless, sometimes there are flaws.
Recently, tests have appeared on the market,Able to determine the onset of pregnancy for 3 or even 6 days before the delay, while the percentage of errors in these tests is quite high. There are many cases when so long the expected and seemingly new pregnancy ended with banal menstrual bleeding. And it's not about the poor quality of the test. Physicians have long proven that a rather high percentage of pregnancies ends before a woman realizes that she was pregnant at all. This is because nature at the initial stage of development produces a so-called selection, when an embryo with obvious genetic defects is literally discarded, and pregnancy is interrupted in a natural way.
When is the best time to conduct a test
But if you hold a test, after waiting at least 2-3Days of delay, his testimony can be trusted almost 100%. Well, maybe at 99. It is quite possible that the test for some time after the delay remains negative, and pregnancy is confirmed only after a few days or even weeks. This is not unusual if we assume that in the previous cycle, ovulation occurred later than usual, and hCG in the urine has not yet reached the concentration required for the reaction. In the instructions for the test, manufacturers always note this point and they propose to wait a couple of days before performing the repeated testing.
False positive reactions
False positive test results, tooMeet, but much less often, and for their appearance there must be a reason. HCG does not disappear from the blood instantaneously, some of it continues to circulate in the body after an interrupted previous pregnancy or special injections made, for example, during the IVF procedure.
And we must not forget about possible fakes, allStill seeping into the trade in illegal ways. Some brands of tests are known for their false positive reaction and are able to show pregnancy not only in women, but also with her husband, and even with a glass of beer, so do not rely on cheapness, but give preference to well-proven products that are likely to give the right Result of testing.