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What Are Evaporation Lines?

What Are Evaporation Lines?

Written by TRACI HOUSTON, WHOLE BODY FERTILITY COACH 

Yes, it is true that a line is a line on a pregnancy test. No matter how dark, light, thick, thin. A second line means that you are, in fact, 100% pregnant! Wrong! While some of us are veterans at trying to conceive and know the ins and outs, some people may not be as familiar with this type of stuff. So why isn’t a line and line on a pregnancy test?

The answer to this question is evaporation lines. What is an evaporation line you ask…

An evaporation line on a pregnancy test is a line caused by the evaporation of urine on the test area causing a false positive result. An evaporation line may be caused by waiting too long and reading the result after the time limit. Although the time limit is usually the culprit for creating an evaporation line it is not always the cause and an evaporation line may develop even within the time limit.

So, a line is a line, is a line, and I am pregnant? Or is a line an evaporation line and I am not pregnant? Hmm, kind of confused here.

An evaporation line does not indicate that a woman is pregnant. When an evaporation line appears, it is best to take another test for an accurate result. 

So how do you tell if it’s an evaporation line or a real line? First of all, you can use pink dye pregnancy tests rather than blue dye pregnancy tests. The blue dye tests have been known to be more likely to give you an evaporation line than the pink dye tests.

You can also only read the result within the time limit! Each brand on pregnancy test should indicate on the box when the test results should be read. It is usually somewhere under 10 minutes with the Fertility2Family tests you need to leave the test for 3 minutes, and after this period the results will be ready to read. Do not interpret test results after 5 minutes. Reading the result after this time frame allows the urine time to evaporate on the test resulting in, yes you guessed it, an evaporation line!

Study the line closely. Does it have colour to it? Or is it more of a grey, a white or an indent. A positive pregnancy test result should be pink (or blue) just like the control line. It should also run from the top of the test window to the bottom of the test window. And have the same thickness as the control line. So basically the test time needs to look like the control line but it does not need to be as dark as the control line.

Another tip to avoid the dreaded evaporation line is to dispose of any damaged or expired tests. They cannot be trusted!

A mark on a pregnancy test may be an evaporation line if:

  • More than 10 minutes have passed since taking the test.
  • The mark is faint and colourless, and it resembles a water spot.
  • The mark has no visible dye in it.

If the control line on the test does not change colour, this means that the test has failed.

A line on a pregnancy test may show a positive result if:

  • There is visible dye in the line, even if the colour is faint.
  • The line appears within the period specified on the instructions, which is usually 3–5 minutes.
  • A woman has taken an early-result test at least 11 days after ovulation.
  • A woman has taken a regular test at least 14 days after ovulation.
  • A woman has missed her period.

So how do you decrease the chances of seeing an evap line?

  1. Don’t test too early. The earlier you test, the lowest your hormone (hCG) levels will be. If you have a real squinter, test again in a day or two. As hCG rises, a true positive test will darken.
  2. Take a more sensitive test. Different test types and brands have different hCG thresholds in order to display a positive result. Because of this, cheap tests that you order online (such as Fertility2Family tests) are more reliable when you test early than digital tests. Keep in mind that the downside of testing early is that you are more likely to find out if you have a chemical pregnancy. These very early miscarriages are quite common, they usually do not signify any kind of underlying fertility problem, and before the advent of highly sensitive pregnancy tests, women might have had chemical pregnancies without even realising it.
  3. Don’t over-hydrate. If you have been drinking a lot of water and/or urinating frequently, your urine may be too dilute for an accurate reading. It’s best to hold your urine for two or three hours to ensure it is not too diluted. First morning urine is usually more concentrated than urine from random hours during the day.
  4. Try urinating in a cup before taking the test, then dipping the test in the urine for the duration specified on the packet. This technique prevents too much urine from splashing onto the test.
  5. Do not use a pregnancy test that is past its expiration date.
  6. Avoid storing pregnancy tests in very hot or cold locations.

Waiting for the results of a pregnancy test can be agonising. A simple way to help ensure accuracy is to take two tests. If both show a line, even a faint one, the result is likely positive.

Anyone who is unsure of the results should give hCG levels time to rise and take another test in a few days. This can reduce the risk of false negatives.

A doctor can provide the most accurate results by testing the blood or the urine.

You can find more posts by TRACI HOUSTON on Instagram