You may hear in the online forums and blogs that pink-dye pregnancy tests are better than blue-dye tests. Is that true? Let’s dig in.
By Halle Tecco
There are a lot of pregnancy test options on the market. When it comes to analog options (you know, the one with two lines), you’ll find two types of tests: those with blue-dye results, and those with pink. You may hear in the online forums and blogs that pink-dye tests are better. Is that true? Let’s dig in.
Pregnancy test 101
Regardless of the dye a manufacturer uses, all pregnancy tests work the same way. Home pregnancy tests detect a hormone called human Chorionic Gonadotropin (hCG). hCG is released into the body when an embryo has been implanted in the uterine wall. If hCG is detected, a test line (pink or blue, depending on the test) will appear. The farther along in the pregnancy, the more hCG will be present in the urine and the darker the line.
Stepping back, what makes a good pregnancy test?
There are a lot of factors that go into making a good pregnancy test. They should be easy to read, accurate, affordable, and sensitive (if you want to test as early as possible).
Let’s start with easy to read. This is where the dye color makes a difference. Blue-dye tests are notorious for getting evaporation lines. It’s unclear if they actually have more evaporation lines, or if they are more likely to be confused for an actual line since a gray-ish evaporation line looks very similar to a blue positive line.
Now let’s talk about accuracy. This may be the most important factor, since you don’t want to get false-negative or false-positive results. It’s important to look at the accuracy stated on the box. Since all at-home pregnancy tests are FDA cleared, most brands have good accuracy these days.
Of course more important than dye-color is the sensitivity of the test. Every brand of pregnancy test has a numeric value of hCG at which it is supposed to detect it. Once your hCG level is at or above that level, you will get a positive result. Since this number varies between pregnancy test brands, one brand’s test may be negative while another will not. See our chart below for the best compilation of pregnancy test brands and their thresholds.
Blue dye vs. pink dye
So which one is better? All else equal, we prefer pink dye tests because they are less likely to confuse users with evaporation lines. That being said, even more important is going to be factors like ease of use, readability, accuracy, and sensitivity.