How to use Babyndex for ovulation prediction

Babyndex makes the saliva ovulation test easy to use and improves its accuracy.

You need an ovulation microscope

Babyndex is the first digital saliva test. The mobile app can automatically interpret the sample, and we supply the ovulation microscope that goes with it.

Take off the removable lens, add a drop of saliva to the glass, and let it dry. In about 10 minutes, put the lens back and press the built-in LED light button. You can read your body's signals by viewing the sample through the microscope.

Depending on where you are in your cycle, you might see dots and circles, fern-shaped crystals (full or partial), or a mix of these. Patterns get denser and sharper as ovulation approaches — the probability of crystals increases.

Babyndex can automatically detect saliva patterns

Instead of interpreting the patterns yourself, use the Babyndex app to detect fern-shaped crystals in your dried sample. Just take a photo with the app and it calculates the probability that ferning is present. It also stores your photos and the daily results, helping you see when you are close to ovulation.

The saliva test shows the fertile window

The rising probability of fern-shaped patterns predicts ovulation. The fertile window is the day of ovulation plus the five days before it — the best days to conceive.

The saliva test is not perfect: you might see ferning outside this window or when pregnant. But if you are ovulating or about to, the crystal-like patterns show up on consecutive days. Day-after-day high crystal probability is what pinpoints the window.

Use Babyndex every day for a full cycle

At first, do the saliva test every day for one full cycle. That is the only way to see how the test behaves for you. Later, you can test daily just before your expected fertile window. Best results come from testing within the five-day period around expected ovulation.

1. Test in the morning when hormone levels are high. Never test after eating, drinking, smoking, or brushing your teeth.
2. Clean the lens before use and carefully pull it out of the casing.
3. Place a drop of saliva on the surface of the lens.
4. Let the sample dry for about 10 minutes, then put the lens back into the housing.
5. Hold the lens against your phone camera and press the light button to take a picture with the Babyndex app.
6. Clean the lens after every use with a soft cloth or lens cleaner.

Common mistakes

Too little sample

With too little saliva there are a few sharp details, but not enough sample for crystals or other artifacts to show.

Too much sample

Too much saliva makes it impossible to tell structural patterns, crystals, and artifacts apart. Avoid creating air bubbles.

Too wet sample

If you don't wait for the sample to dry, details are visible but blurred. Let saliva dry for about 10 minutes before replacing the lens in the housing.

Advantages of Babyndex

Analogue saliva ovulation tests are hard to interpret and rarely live up to their potential. Babyndex is the first digital saliva test that can detect pattern changes automatically. A 2018 Harvard study found the same approach to be over 99% accurate — a much less intrusive and more affordable way to detect estrogen changes than urine or electrolyte tests.¹

Babyndex should not be used as a contraceptive device

The fern-like crystals begin to appear around 3–4 days before ovulation, thanks to the rise in estrogen and salt levels. In 2012, the FDA approved the saliva test for ovulation prediction.² Some sites advertise saliva tests for contraception — we do not, because they are not reliable for that. Likewise, a positive result does not guarantee pregnancy.