Pregnancy tests, including home pregnancy tests, are generally a very reliable way to determine whether or not a woman is pregnant. Home pregnancy tests are, generally, around 97% accurate. While this is not a bad percentage, it does mean that 3% of the time you will have a false reading. 3% doesn’t sound so bad until, of course, you are in that 3%. However, it is important to understand the things that can alter a pregnancy test, including how medications, such as Elavil, may or may not alter a pregnancy test.

First, it is important to understand exactly how a pregnancy test works. Home pregnancy tests measure a hormone known as, human chorionic gonadotropin, also known as hCG for short. For a pregnancy test to show a positive result, your body must be producing a level of hCG that the test can detect. Not all pregnancy tests are the same, however. Some tests are more sensitive than others and will show a positive result earlier than tests that are less sensitive. More sensitive tests look for lower amounts of hCG. Here is where some medications can alter a pregnancy test.

Medications that contain hCG, such as Novarel, Profasi, and Pregnyl can, occasionally, alter a pregnancy test. For this to happen, however, the medications need to still be in the system at the time that the pregnancy test is taken. Generally, for drugs that are given by injection, this means that the injection must occur within a week or two of taking the pregnancy test. Medications that do not contain hCG, such as Elavil, are not known to alter a pregnancy test.

There are other things that can alter a pregnancy test. Waiting too long may make lines fade, for example, on some types of tests. Reading the test too early can also leave an invalid result. A chemical pregnancy, which refers to a miscarriage in the first couple of weeks after fertilization, can also leave a false positive pregnancy test, as can evaporation lines on the testing equipment.

The most reliable way to determine pregnancy is to confirm with a health care provider, who can use more advanced testing measures, to determine if anything has altered the results of your pregnancy test.

This entry was posted in Getting Pregnant.