What is the reason why the pregnancy test stick is invalid?

When it comes to pregnancy test sticks, most people are familiar with them. Everyone knows that early pregnancy test strips are used to detect whether you are pregnant. Usually, pregnancy test sticks are very simple to use, so most women have them at home, which is convenient for them to test at home, and the results of pregnancy test sticks are also very fast. Some people have invalid results after using pregnancy test sticks. What is the reason for the invalidity of pregnancy test sticks?

Why is the early pregnancy test paper invalid?

The usage and production of early pregnancy test strips are relatively simple. Early pregnancy test strips are just a simple piece of paper. A substance that can detect hCG in urine is added during the production process. The gold label method is commonly used. Because it is different from detecting the hCG content in the blood, the early pregnancy test strips appear to be a bit rough during the production and use process, so the results are not 100% accurate. Some early pregnancy test strips have low accuracy due to quality problems, so people are best to choose high-quality early pregnancy test strips when purchasing.

In addition, early pregnancy test strips have a shelf life, and the defective rate in the production process cannot be avoided. During the storage and sales process, poor storage environment of the pregnancy test strips may also cause the pregnancy test strips to become ineffective. If women find that the early pregnancy test paper they are using is ineffective, they can use it again the next morning, or buy another brand of early pregnancy test paper.

How long does it take to use the pregnancy test?

The working principle of self-testing pregnancy using early pregnancy test strips is to detect the hCG value, that is, the value of human chorionic gonadotropin. This hormone is produced by the placenta and begins to be secreted when a fertilized egg implants. After the fertilized egg implants, the level of this hormone in the urine is relatively small at first, and the level in the blood is more accurate. Therefore, blood tests for early pregnancy are more accurate, while hcg in urine will only be obvious after a week.

The working principle of self-testing pregnancy using early pregnancy test strips is to detect the hCG value, that is, the value of human chorionic gonadotropin. This hormone is produced by the placenta and usually appears in the urine a few days after pregnancy. However, due to the small amount, it is difficult to test it at the beginning and it only becomes increasingly obvious after 10-14 days.

It usually takes about 7 days from intercourse to pregnancy, which means that pregnancy can be tested on the day of pregnancy (equivalent to 7 days after intercourse), but the accuracy is not high. Generally, the test results will be more accurate if you test again 14 days after having sex.

The reason why early pregnancy test strips are invalid is generally due to improper operation and improper storage. If you want to get the best results, it is best to use early morning urine for testing, and do not drink too much water before the test, otherwise the urine will be diluted, and the hcg content in the urine will be less, making it more difficult for early pregnancy test strips to detect whether you are pregnant.