The pregnancy test can result in a false positive, however, this is a very rare situation that occurs most often in home-based pharmacy tests, mainly due to usage errors or because it is obsolete.
Another common cause of this result is the so-called chemical pregnancy, in which the egg is fertilized, but cannot be implanted correctly in the uterus and ultimately does not develop. When this happens, the body begins to produce hormones that lead to pregnancy and therefore the first test is positive. However, because pregnancy doesn’t last, a new test a little later can be negative.
- In addition.
- Women who undergo infertility treatment with hCG injections or who have tumors capable of producing this hormone may also have a false positive result on a pregnancy test.
- Either at a pharmacy or in a blood test.
Changes in results usually occur when the test is out of date, and therefore it is very important to confirm the expiration date before using it. However, if successful, there are other causes such as:
Before using the pregnancy test in pharmacies, it is important to read the manufacturer’s instructions, especially as far as the time it takes to read the result. In fact, some tests may show a change in the result after the recommended reading time.
In addition, before using the test, it is also recommended to wash the intimate area with water, as some soaps or intimate creams may react with the test, resulting in the appearance of a false positive or negative, for example.
Learn how to take the pregnancy test at pharmacies and understand the outcome.
This type of pregnancy occurs when the egg is fertilized, but the embryo has not been able to attach to the uterus. In these cases, the body begins to produce the hormone hCG and therefore can be detected in urine or blood tests, however, as the embryo was not in the womb, is eliminated and a bleeding miscarriage occurs, which may be wrong. with delayed menstruation.
Some medications used to treat infertility problems contain high amounts of hCG, the hormone that is evaluated in pregnancy tests and can therefore result in a false positive shortly after treatment.
In addition, other common medications such as certain anticonvulsants, diuretics or tranquilizers may also alter the outcome. For example, it’s important to read the instructions or have a blood test in the hospital, informing your doctor of the medications used.
Although rarer, false positives can also occur in cases of disease, especially in cases of hormone-producing tumors, such as breast or ovarian cancer.
To avoid having a false positive result, it is very important to follow all the instructions in the pharmacy test box and, after passing the test, make sure:
However, the most reliable way to avoid changes in the result is to do a blood test with a beta-hCG evaluation, because in these cases, there is less chance of changing the result. In addition, before the test, your doctor performs an evaluation to determine if there are medications or other conditions that may cause a false positive. Learn more about the hCG beta exam.