Blue Dye Pregnancy Test: What Is It?

Not too sure which pregnancy test you should take?

You may have heard of pink dye pregnancy tests — they’re probably the most common types you can buy in your local drugstore.

But, are you clued up on blue dye pregnancy tests? 💙

Are they different to pink dye, and which one is better for the most accurate test?

We’ve got you covered.

Let’s explore pink vs blue dye pregnancy tests in detail, and work out which is best for you. 👇

In this article: 📝

What are blue dye pregnancy tests?

Put simply, blue line pregnancy tests are a type of home pregnancy test you can use.

You can get blue dye tests in either standard pregnancy test stick form (the traditional pee-on-a-stick) situation, or as pregnancy test strips you can dip into a pot of urine instead.

Once you’ve peed on the stick, or dipped the test in urine, blue dye will show up to let you know the results. 💙

It will either show one blue control line, which shows the test has worked (and you’re not pregnant), or will it show two blue lines — telling you that you’re pregnant. 👶

How do blue dye pregnancy tests work?

All home pregnancy tests are on the hunt for a hormone called hCG in your urine.

This crafty little hormone helpfully lets you know when you’re pregnant, as hGC levels rise significantly in pregnant women.

So, by combining the test with your pee (be sure to read the instructions carefully, as the step-by-step can vary between brands!), it’ll be able to tell you whether you’re pregnant or not.

In the first 4 weeks of pregnancy, your hCG levels typically double about every 2 to 3 days — which means, the longer you wait to test, the more chance there’ll be for a positive test to show up if you’re pregnant.

So, that little blue dye really can do wonders! 💫

Are blue dye tests more accurate?

So, all pregnancy tests work in the same way.

But, some people do prefer pink dye tests.

And that’s probably because, with pink dye tests, people say there’s less chance of evaporation lines happening.

“An evaporation what?!”

An evaporation line happens when you read the result after the wait-time window, and the urine has dried on the test*.

It looks like a positive result, but it’s actually just an evaporation line. 😖

And because an evaporation line can be a gray-ish color, it’s harder to tell against the blue dye test if it’s an evap line or a BFP.

So, some believe that pink dye tests may be more accurate than blue dye, but it’s mainly to do with how you read the results.

But, how do blue line pregnancy tests compare to digital tests?!

Digital pregnancy tests work in the same way dye tests do, but display the results in word form, as either ‘Pregnant/Not pregnant’ or ‘Yes/No’.

Super handy and easy to read! 🔍

Most digital tests say they’re 99% accurate (depending on the brand), but some people find digital tests more accurate visually, as there’s less room for error from interpreting the results.

Do blue dye tests give false positives?

As mentioned above, blue dye tests can often create the illusion of false-positives, also known as evaporation lines.

This is generally more common in blue dye tests rather than pink dye tests because a gray-ish colored evap line can look pretty similar to a blue positive line.

Whereas, an evap line compared to the pink is a little bit more obvious.

But, although blue dye tests can give the impression of a false-positive, so can pink dye… it may just be easier to tell the difference on a pink dye test. 🤷‍♀️

How common are blue evaporation lines?

Well, that’s the thing — it can happen at any time.

But they don’t happen all the time. 🤷‍♀️

It’s generally more likely to happen if you wait until after the time-period stated to check your test — so it’s really important to keep an eye on the time. ⏳

Some women may see this a few times, while others may never experience it.

Are blue dye pregnancy tests more sensitive?

Both blue and pink dye tests are in the same league of sensitivity levels (e.g. 25 mIU/ml).

But pink dye tests may be just slightly easier to read, with less chance of evap lines.

But that doesn’t mean they’re more sensitive — it just means the color of the dye can cause an evaporation line to go unnoticed!

What does a positive blue pregnancy test look like?

A positive blue dye test will show two lines.

This could either be two vertical lines: ⏸️

Or it could be shown in two lines making a plus sign: ➕

The results of a blue dye test are shown in the same way as a pink dye test— with the only difference being the color of dye. 💗 💙

What does a faint positive look like on a blue dye test?

Now, this is where we need to be careful, and get our inspection-eyes at the ready. 🔍

A faint positive line on a blue dye test could be a positive pregnancy test.

But it could also be an evaporation line. 🤷‍♀️

It can be really tricky to tell the difference between the two.

That’s why we say it’s best to wait until the first day of your missed period to take a test, just to make sure any hCG in your urine shows up to the party! 🥳

Is a faint line on a pregnancy test blue dye?

It could just be blue dye from an evap line.

But, it could also be a positive result.

Best thing to do is take another pregnancy test in the morning (as that’s when the hCG is most likely to come out to play), and compare your results.

If you think you do have a positive pregnancy test, you’ll then need to book in with your doctor who’ll do a blood pregnancy test to confirm. 👶

Blue or pink dye pregnancy test?

So, the big decision…

💓 or 💙?

It’s totally up to you — both will be able to tell you whether you’re pregnant.

But you may need to get acquainted with your line eyes if you choose blue dye. 😵‍💫

Both can be easily bought from your local drugstore, and are generally reasonably priced (not as costly as digital pregnancy tests!). 💰

Ready to take your test, but could do with some moral support?

We’re here with you every step of the way. 🤗

Join us on Peanut to chat with women in the same boat as you, and go through it all together. 🥜