Which line appears first on the pregnancy test stick?

For women who are using a pregnancy test stick for the first time, it is normal not to know how to use it correctly. At this time, we just need to follow the instructions. The principle of using a pregnancy test stick to detect pregnancy is that the substance on the pregnancy test stick can react chemically with a substance called HCG in the body, and the pregnancy can be detected from the chemical reaction. When we use a pregnancy test stick, we only need to bring our urine into contact with the substance on the pregnancy test stick.

1. Principle of pregnancy test stick detection

The pregnancy test stick mainly determines whether a woman is pregnant by measuring the HCG value in her body. HCG, or human chorionic gonadotropin, is a glycoprotein secreted by trophoblast cells of the placenta. After the fertilized egg implants, during the development of the fetus, the placental syncytiotrophoblast cells produce a large amount of human chorionic gonadotropin (HCG), which is excreted into the urine through the pregnant woman's blood circulation. Therefore, during the 1st to 2.5th week of pregnancy, the HCG levels in serum and urine will increase rapidly, reaching a peak in the 8th week of pregnancy. Therefore, the pregnancy test stick determines pregnancy based on the measurement of HCG value.

2. How to use a pregnancy test stick

After purchasing the pregnancy test stick, first tear open the packaging film along the notch and take out the pregnancy test stick. You can see that there is a plastic strip with a window at one end of the pregnancy test stick. Secondly, pinch one end of the handle of the pregnancy test stick tightly with your thumb and tilt the end with the urine suction hole downward. Note that the observation side of the pregnancy test stick should face downward and the direction of the plum blossom pattern should face upward. When urinating, aim at the urine suction hole on the side of the pregnancy test stick, allow the urine to pass through the urine suction hole, and maintain the urine collection time for 1 to 2 seconds. The specific instructions will have detailed illustrations. Then wait for the results to appear. Typically, the result may be displayed as a minus "-", a plus "+", or some specific color.

3. When is the most accurate time for testing?

How long after amenorrhea can a pregnancy test be used more accurately? This is the question women want to know most. Doctors suggest that if fertilization is successful at this time, it will take at least 6 or 7 days for the fertilized egg to produce HCG, and pregnancy test sticks are determined by testing urine HCG. HCG really starts to be secreted in large quantities after the fertilized egg implants, and the syncytial trophoblast begins to secrete large amounts of HCG. It takes at least 11 days for the fertilized egg to implant. So, the earliest is 6 days. If you want more accuracy, wait until 11 days, as it will be more accurate then.

It is relatively accurate to test within one month of pregnancy or 7-10 days after menopause. When using it, you should choose the first urination in the morning for higher accuracy. Generally, hCG will appear in the urine a few days after the fertilized egg and sperm combine, and it must reach a certain ratio to be detected. It also depends on the method of use. If it is used improperly, there will be errors.