Unfortunately, in a pregnancy test, the second strip can not always be seen clearly, it can be barely noticeable. How do you get an accurate result, you ask? To answer this question, let’s look at how pregnancy tests work and what factors affect their accuracy.
How do pregnancy tests work?
They all use the same principle – they react to an increase in the hCG hormone in the urine. After conception, the girl’s body immediately begins internal restructuring, so the placenta, which produces the hCG hormone, actively begins to develop. It is no coincidence that it is also called the “pregnancy hormone”.
For girls who are not pregnant, the hCG rate is 0-5 mm. The hCG level begins to rise immediately after conception. After 1-2 weeks, it already exceeds the norm, is 25-100 mMems, at 6-7 weeks it reaches a maximum of 27300-233000 mMems, after which a gradual decrease begins.
Manufacturers guarantee the accuracy of home pregnancy tests at a level of at least 95%. But most of them tend to overestimate this figure and indicate the accuracy of 99%, in fact, it depends, among other things, on the correctness of the procedure performed. When using the test, do not be lazy, read carefully the instructions for it, follow all the recommendations.
In the late 90s of the last century, a survey was conducted, the results of which showed that if a woman followed the instructions correctly, the accuracy of the household test was about the same as in the laboratory – 97,4%. If the woman did not follow the instructions, the accuracy dropped to 75%. That is, in such cases, the risk of an erroneous test result is high.
A false positive is a test result when there is no pregnancy and the test indicates a positive result. It can be caused by:
- taking medications that contain hCG;
- the presence of tumors;
- a little time has passed after the termination of pregnancy (the level of hCG has not yet had time to decrease).
False negative – a test result in which there is pregnancy, but the test shows that the result is negative, i.e. the test does not show the onset of pregnancy. The reasons for this phenomenon are usually the following:
- the use of a large amount of liquid or diuretics (in this case, the hormone is diluted with the liquid, as a result of which the desired concentration is not achieved);
- the test was carried out very early (the level of the hormone has not yet had time to rise to the desired level);
- there are kidney diseases (in this case, HCG is not excreted in the urine in such an amount that is needed).
How can you achieve greater accuracy when conducting a pregnancy test? Here are the expert tips:
- the test should be carried out in the morning, when the concentration of HCG is highest;
- wait for a delay in menstruation, or at least wait 1 week after possible fertilization (the next day after conception, the test is useless to do, since it will not show anything);
- use two or three different tests.
How should the results of a pregnancy test be evaluated?
- you have both stripes – this indicates a positive result (you are pregnant);
- there is only one strip in the test, which means that the result is negative (there is no pregnancy);
- the second strip is faint or indistinct – also means a positive result (the fact is that the concentration of the hormone is still too low);
- missing strips on the test indicate an erroneous result, such a test cannot be trusted (perhaps the expiration date has expired or the test was performed incorrectly).
That is why it is always necessary to retest after 3-4 days. This diagnostic method, of course, does not replace a gynecological examination. If the critical days have not come, be sure to show yourself to me, no matter what the test showed. In any case, it is worth remembering that no matter what test you use, only a doctor can finally confirm the onset of pregnancy. If the test is positive, be sure to visit your gynecologist as well.
Never trust a test 100% to avoid disappointment. Remember, error is always possible.