Evaporation Line on Pregnancy Test

Pregnancy tests aren't as easy as they seem

If you've ever taken a home pregnancy test, you may wonder what an evaporation line on a pregnancy test means.

Home Pregnancy Tests

Depending on what type of home pregnancy test you purchase, your results may involve looking for one or two colored lines. The color differs depending on the brand, which is why it's so important to fully read the directions so that you know what you're looking at when you read your results. For some home tests, just one line indicates a positive result, while other tests will show two lines when you're pregnant.

What is an Evaporation Line on Pregnancy Test?

In addition to reading the line results correctly, there's also the time factor. Pregnancy results are meant to be read in an indicated amount of time, usually within five to ten minutes. If you wait longer than that to read your results, they may be interpretted inaccurately. This is because the urine that's on the test strip eventually evaporates and dries and can lead to misleading lines. A negative result that's read within two minutes of testing may then read positive if you wait 15 more minutes. This doesn't mean you're pregnant...it simply means that the results are too old to be interpreted accurately.

An evaporation line can show up as a faint line on a pregnancy test. Generally, they don't have a specific color, as a positive or negative line would. Evaporation lines usually show up as a shadowy line.

Avoid Reading the Wrong Results

So what should you do when taking a home pregnancy test to ensure that you get accurate results? This is important for women who want to conceive as well as those who are trying not to get pregnant (in which case, a variety of contraceptives are available and should be used correctly):

Read the directions fully: Different home tests may have different directions. If you use more than one test too make sure you're getting the right results, read the directions for each test and follow them to the letter.

Take a home pregnancy test at the right time: Some early pregnancy tests claim accurate results the very first day that you miss your period, while others recommend waiting until your period is a few days late. The brand of test you use should tell you in the directions how early pregnancy can be detected.

Read your results within the right time frame. After this time frame is up, you may get inaccurate results due to an evaporation line on a pregnancy test. Some tests will give you results within a minute, while others tell you to wait about five minutes before reading the results. If you use different brands, make sure you adhere to the recommended time for each brand to get the correct results.

If You See an Evaporation Line

If you see a shadowy line after you read the results of your home pregnancy test and you're not sure what this means, it's best to either take another test (the next day, first thing in the morning, when pregnancy hormones will be at their peak in your urine) or take a test in your doctor's office. Whether you're trying to conceive or not, having the correct results is important, for you as well as the potential fetus.