What is the principle of pregnancy test stick

The pregnancy test stick is a special tool used by women to check whether they are pregnant. The detection principle is based on the human chorionic gonadotropin (HCG) in the urine of the human body. If two lines are displayed on the pregnancy test stick, you are pregnant (positive).

HCG is a gonadotropin secreted by the embryo of pregnant women. It is distributed throughout the body with the blood and acts on target organs. A certain concentration of HCG is also present in the urine.

The vast majority of pregnancy test products on the market use the colloidal gold method, which uses the principle of double antigen sandwich chocolate to determine whether the pregnancy is confirmed by judging or semi-quantitatively testing HCG in the urine. It is important to note that this type of pregnancy test product is not 100% accurate. Some diseases may also cause an increase in the body's HCG concentration, leading to a positive result.

Instructions for use of pregnancy test sticks

Testing in the early stages of pregnancy: High sensitivity, that is, it can be detected two days after the sperm and egg combine in the uterus and the embryo implants, which is about 7 days before the next menstrual period.

Accuracy: High accuracy, because it uses double-layer ultra-sealed aluminum foil packaging to ensure that the product will not get damp for a long time. Even the product stored for 2 to 3 years still has a good quality level.

Response: Information results can be displayed within 1 minute, and as fast as 30 seconds. You don't have to wait for a long time and can find out whether you are pregnant more quickly.

Result: The cloning technology is used, the processing technology is delicate, and the lines showing the results are clearer and more prominent.

Pregnancy test stick accuracy

The accuracy of a reliable pregnancy test stick is around 85% to 95%.

First of all, we need to clarify some issues: the ovulation period is around the 14th day of the menstrual cycle. If fertilization is successful at this time, it will take 6 or 7 days for the combination of sperm and egg to produce HCG, and the pregnancy test sticks are all determined by testing urine HCG. HCG actually starts to secrete in large quantities after the fertilized egg implants, and the transformed trophoblasts begin to secrete and produce HCG in large quantities. It takes at least 11 days for the fertilized egg and embryo to implant.

Therefore, for the first 6 days, if you want to be more precise, wait until 11 days, then it will be more accurate. You can infer it yourself.

The result of pregnancy (positive type) can be judged after 1 minute (30 seconds at the fastest), which means that if two lines are clearly displayed after 1 minute of the test, it shows the result of pregnancy (positive type) and there is no need to wait until 3 minutes later to judge.

The result of not being pregnant can only be confirmed after 3 minutes. This is because in the early stages of pregnancy, the HCG hormone content in the urine is very low, and a weak positive result may appear during the test. The weak positive result may not be displayed after 1 minute. With the increase in the reaction speed, it will take 3 minutes for two lines to be displayed. At this time, the appearance of two lines should still be judged as a pregnancy (positive) result; if there is still only one comparison line after 3 minutes, it can be judged as a not being pregnant (negative) result.

The result judged after 5 minutes is invalid! This is because the judgment within 5 minutes is the test basis for product design. The result of judgment beyond 5 minutes or even longer is not clear. Some people may have a positive result, but this result does not mean the specific situation.