A pregnancy test meter is a simple device that is used to determine whether the woman is pregnant. Pregnancy markers are present in urine and blood, and the meter utilizes these markers to diagnose pregnancy.
One of the most important markers is human chorionic gonadotropin (hCG), which was discovered in 1930. HCG is be produced by the syncytiotrophoblast cells of the fertilised ova (eggs) and is a reliable marker of pregnancy. However, it cannot be detected in blood or urine until there is implantation of the fertilized ovum. This might create false negative results, particularly if the test is done in very early stages of pregnancy.
In a published review, it was mentioned when the meter is used by experienced technicians, results were as accurate as laboratory results, i.e. around 97.4%. However, when the consumers use this product, the accuracy fall to 75%. Misunderstanding or failure to execute the instructions properly on the part of the users contributes to both false positive and false negative results.
False negative results can come on the meter if testing is done too early as mentioned early since implantation occurs around 6 to 12 days after ovulations. Since the hCG levels continue to rise till the 20th week of pregnancy, the probability of false negative results tend to reduce with time.
False positive meter readings may occur due to several reasons like errors of test meter, use of meters after their expiry dates, non-pregnant production of the hCG molecule, use of drugs containing the hCG molecule, consumption of other medications like phenothiazines, chlorpromazine, clomid, methadone, infertility treatment, diseases like enterocystoplasties, gestational trophoblastic neoplasms, choriocarcinoma, germ cell tumors, IgA deficiencies, gestational trophoblastic diseases (GTD), heterophile antibodies etc.
Steps to use the pregnancy test meter
- Step 1: the woman’s urine is collected in a clean, dry glass or plastic container.
- Step 2: the hCG strip is removed from the pouch and dipped in urine in the direction of the given arrow. The urine level must not go above the maximum line.
- Step 3: the meter is taken out of the urine after 3 seconds and placed on a clean dry surface. The result can be checked in 5 minutes.
- Step 4: when the test strip is placed in urine sample, urine goes to the covering by capillary action. When hCG reaches the test zone area, there is formation of a colored line. Absence of colored line implies negative result.
- Step 5: only 1 colored band, means negative result; 2 colored bands indicate positive result.