1. The time of detection. HCG usually appears in the urine a few days after the fertilized egg is implanted, and it must reach a certain amount before it can be detected. Therefore, for women with normal menstruation, HCG may be detected in the urine only after the menstruation is delayed. However, women with long menstrual cycles or abnormal ovulation may not be detected until 40-44 days after menopause.
2. Some diseases and drugs may cause false positive results. Some tumor cells, such as hydatidiform mole, choriocarcinoma, bronchial carcinoma and kidney cancer, can also secrete HCG.
3. Do not use expired test strips. Because chemical reagents will lose their effectiveness after a long period of time, pay attention to the production date when purchasing.
4. Do not use test paper that has been damp.
If the self-test result is negative and your menstruation is still fluctuating after 1 week, you should do the self-test again. If it is not positive, it is best to see a doctor. Believe in your body. If you have all kinds of pregnancy symptoms, then regardless of the self-test results, you should think that the principle of the early pregnancy test strip is only a preliminary test, and there will be errors in the use of the early pregnancy test strip. The best way is to go to the hospital for HCG blood test, HCG urine test and B-ultrasound. If you are not ready to welcome your baby, it is necessary to detect the early signs of pregnancy and determine whether you are pregnant.
5. When women of childbearing age have early pregnancy reactions such as menopause, it is not possible to determine whether they are pregnant with just one early pregnancy test paper. The most reliable thing is to conduct a comprehensive examination, especially for those with weak positives, perform HCG blood test, HCG urine test and B-ultrasound examine. In order to take measures as soon as possible.
6. After three months of pregnancy, the HCG level will drop. If the early pregnancy test paper is used at this time, it may be negative or weakly positive.
7. After the use period, the effect will be lost, please go to the hospital for inspection in time! [1]
Colloidal gold early pregnancy test paper has a positive urine test
A positive urine test indicates that β-HCG≥25U/L, and the strength of the T line reflects the concentration of HCG.
1. Pregnancy:
(1) Normal pregnancy: During normal pregnancy, HCG reaches its peak value (about 50000-100000U/L) on 60-70 days after menopause.
Inspection Method
Inspection Method
It lasted for 1-2 weeks and started to drop to normal 2 weeks after delivery. The T line deepens with the increase of HCG in the early stage, and the "high concentration effect" appears when it is close to the peak (the T line weakens with the increase of HCG).
(2) Ectopic pregnancy: β-HCG does not fall to normal until 8-9 days after ectopic pregnancy. Urine test may also be positive.
2. Abortion or recovery period of childbirth: Generally, β-HCG will fall to normal after artificial abortion and spontaneous abortion. It takes 30 days and 19 days respectively, and it takes 12 days to return to normal when there is no placenta remaining in full-term delivery. The urine test may be positive before returning to normal.
3. Reproductive system diseases: β-HCG of reproductive system diseases such as mole, erosive mole, choriocarcinoma, and trophoblastic tumors are all abnormally increased (>100000U/L). The "high concentration effect" caused by excessive concentration makes the T line weaker.
4. Cross-reaction caused by homologous a-chain: A small number of women of childbearing age may cause false positives during the ovulation period due to homologous a-chain, especially when the level of hormones is high and the urine is concentrated.
Colloidal gold early pregnancy test paper has a negative urine test
1. Negative urine test indicates β-HCG<25U/L
(1) Not pregnant.
(2) Ectopic pregnancy: In patients with ectopic pregnancy, the β-HCG in urine may be lower than 25U/L. Therefore, it is necessary to combine blood β-HCG, clinical symptoms and imaging examinations to assist diagnosis in clinical practice.
2. High-concentration hook effect: When the concentration of β-HCG is too high, false negatives may occur due to the "high-concentration hook effect".
3. Improper use of reagents: When the urine sample exceeds the MAX line or the sample loading speed is too fast, the sample does not bind to the labeled colloidal gold antibody due to the chromatographic force, and directly migrates to the C and T line regions, regardless of β-HCG There are no C and T lines for the content.
4. Reagent failure: At this time, no matter how much β-HCG content is, there is no C, T line.