When the Pregnancy Test can give a False Positive

The pregnancy test can give the result of false positive, however, this is a very rare situation that occurs more frequently in pharmacy tests performed at home, mainly due to errors in the mode of use or because the product is found defeated.

Another common cause for this result is the so-called chemical gravity, in which the egg is fertilized but fails to implant properly in the uterus, so it does not develop. When this occurs, the body begins to produce hormones to maintain pregnancy and, therefore, the first test can be positive. However, as the pregnancy does not continue, if a new test is performed sometime later, the result should be negative.

In addition to this, women who perform infertility treatment with hCG injections or who have tumors that can produce this hormone may also have a false-positive result both in the pharmacy test and in the blood test.

Main Causes of a False Positive

Alterations in the result generally occur when the test is expired and, therefore, it is very important to confirm the expiration date before using it. However, if it is correct, such as:

1. Incorrect use Mode

Before using the pharmacy pregnancy test it is important to read the manufacturer's instructions, especially about the time to wait to read the result. This is because some tests may present changes in the result after the recommended reading time.

In addition to this, before using the test it is also recommended to wash the intimate region with water, since some soaps or intimate creams may react with the test, causing a false positive or negative, for example.

See how to perform the pharmacy pregnancy test and how to understand the result.

2. Chemical Pregnancy

This is a type of pregnancy that occurs when the egg was fertilized, but the embryo failed to attach itself to the wall of the uterus. In these cases, the body begins to produce the hCG hormone, being detected in the urine or blood test, however, as the embryo was not maintained in the uterus, a spontaneous abortion with bleeding occurs, which can be confused with late menstruation.

3. Use of some Medications

medications used in the treatment of infertility problems contain a high amount of hCG, the hormone that is evaluated in pregnancy tests, so it can give a false-positive result shortly after treatment.

In addition to this, other more common medications such as some anticonvulsants, diuretics or tranquilizers can also cause changes in the outcome. In this way, it is important to read the medication leaflet or perform the blood test in the hospital, informing the bioanalyst about the medications used.

4. Health Problems

Although it is rarer, the false positive can also arise in cases of disease, especially in cases of hormone-producing tumors, such as in breast or ovarian cancer, for example. See more about breast cancer.

How to Avoid the False Positive

To avoid having a false-positive result, it is very important to follow all instructions on how to use them inside the pharmacy test box. Also, after having the pregnancy test you must:

• Repeat the test 3 to 5 days later;
• Do not reconfirm the test after the indicated time;
• Mark a consultation at the gynecologist after 4 to 5 weeks.

However, the most reliable way to avoid changes in the result is to have a blood test with evaluation of the beta hCG hormone, since in these cases there is less chance of changes in the result. Learn more about the hCG beta test.

In addition to this, before the exam, the doctor performs an evaluation to identify if there are medications or other situations that can cause a false positive.