Pregnancy tests are generally easy to read and can be up to 97 percent accurate. But the pale or faint lines that sometimes appear in the pregnancy test window can frustrate a woman who is counting on the test to provide an accurate result. Although a faint line on a pregnancy test can be considered a positive result, sometimes it can be caused by an evaporation line, which leads to a false result.
In most cases, if you are pregnant, you will see a dark, unmistakable result. The lines, or occasionally symbols such as plusses or minuses, are made from special chemicals that turn a dark color when they react with certain hormones. In most tests there are two results. The first one is the one that tells you if you’ve done the test right, reacting with molecules that are normally present in urine. The second one, the one that tells you if you’re pregnant, reacts with a pregnancy hormone called human chorionic gonadotropin (hCG).
Causes for Faint Line on Pregnancy Test Results
There could be a couple of different reasons why your pregnancy test is giving faint line or mixed results, rather than unmistakable ones:
Failure to follow instructions properly – Unfortunately this is the number one reason why pregnancy tests yield false results, as well as faint lines instead of bold ones. There are two types of at home pregnancy tests; one that has you urinate on a stick, and one that has you urinate into a dry, clean cup or container. It’s truly important that you don’t read the results too soon or too late, rather reading them in the allotted time given, usually 5-10 minutes. Reading the results before or after the time slot given, can leave evaporation lines, which in themselves are faint or pale in color. It can look like a faint positive, but it’s really just the result of the urine evaporating and leaving a residue behind.
Too early in the pregnancy – Home pregnancy tests look for the hormone hCG in your urine, however this hormone needs a little bit of time to reach the correct concentration for the at-home tests to pick up on. From conception until about a week after your period, the hCG levels are too low for an at-home test to accurately register. In some cases, there might be just enough levels of hCG for a test to yield a faint line within the window. It’s important to know how sensitive your test is, as different brands have different sensitivity levels that can pick up on hCG levels sooner than others.
Evaporation Lines – Evaporation lines are faint in color, and usually show up after the time frame in which the test calls for. They can be misread as a positive result, when in actuality they are the result of the urine evaporating and leaving a residue behind. They can happen to any brand, so again, it’s important you check for results by reading the test within the time frame given.
Positive pregnancy result – If you are using an at-home pregnancy test kit, sometimes it does yield a faint line as a positive result instead of a bold line, as long as you’re reading the results within the time allotted and you followed the instructions properly. It’s really important that you retest yourself, generally in the morning right after waking up, to ensure a positive result.
Diluted urine – As mentioned before, it’s best to test for hCG in the morning, right after you wake up since this is the time of day that the concentration levels of hCG are at their highest. As you drink water and other fluids throughout your day, your hCG levels decrease.
Chemical pregnancy has occurred – A chemical pregnancy is referred to as an early miscarriage. Meaning implantation takes place (hCG is produced for a short time) followed by a miscarriage (generally, before any other pregnancy symptoms are detected). This can be devastating to those trying to conceive, however, it can be the cause of a faint line on a pregnancy test.
What To Do About a Faint Line on a Pregnancy Test
If you’ve taken a pregnancy test at home and gotten a faint line as a result, the best thing to do is to take the test again. You may want to try different brands with different sensitivity levels. Another option is to visit your healthcare provider and have him or her administer a blood test.