Science (Layout Example)

Plan your future confidently

Since inventing the world’s first fertility tracker in the mid-80’s, 
accuracy has always been our top priority. 

 

Backed by 40 years of scientific research, we’re proud to bring you 
cycle predictions you can trust — whatever your family plans may be.

Our fertility trackers are

Registered medical devices

Supported by 17 clinical studies

Created by doctors and scientists

Your fertility isn’t a guessing game

We get it – switching to a natural method of family planning 
can feel like a risky move if you’re not trying to build your family just yet. 
Without the right tools, it’s normal to worry if you can rely on it. 

We created these devices to provide women everywhere with a
safe, reliable, and non-invasive alternative to traditional methods.
So you can easily use basal body temperature (BBT) to
track your cycle and fertility stress-free.

How to track your cycle with basal body temperature

Basal body temperature (BBT) marks the low point of your body temp, just after a longer period of rest. Changes in BBT indicate where you are in your cycle:

During the follicular phase (from menstruation until ovulation), BBT remains stable around 97.7ºF. After ovulation, progesterone levels go up, causing BBT to rise between 0.4º – 0.81ºF. BBT stays elevated for around 12 – 16 days until the next period starts. If the egg isn’t fertilized, progesterone levels drop, causing BBT to go down. If BBT remains high for over 18 days, it can be an early indication of pregnancy.

Because the temperature change is so subtle, it’s vital to use a highly sensitive thermometer that measures beyond one decimal point. This level of precision is necessary to reliably use this method for family planning, and isn’t possible with other basal body thermometers and wearables.

Aside from ultrasound, BBT is the most accurate way to track ovulation.

You can learn more about the intricacies of fertility tracking with BBT in our e-book.

Tell me more about BBT

Get daily predictions you can count on

After just 60 seconds of measuring your temperature, Daysy and Lady-Comp display your fertility status with a red (fertile) or green (not fertile) light. Yellow means that the device is learning about your cycle.

Using your measurement data, the algorithm performs advanced statistical analyses to reliably predict your fertile window, or the 6 days per cycle when pregnancy is possible. You’ll see this as red and green days in your DaysyDay app or Lady-Comp display.

Even if your temp is elevated due to illness or stress, or you have an irregular sleep schedule, you can always rely on your device to give an accurate fertility prediction.

During the follicular phase (from menstruation until ovulation), BBT remains stable around 97.7ºF. After ovulation, progesterone levels go up, causing BBT to rise between 0.4º – 0.81ºF. BBT stays elevated for around 12 – 16 days until the next period starts. If the egg isn’t fertilized, progesterone levels drop, causing BBT to go down. If BBT remains high for over 18 days, it can be an early indication of pregnancy.

Because the temperature change is so subtle, it’s vital to use a highly sensitive thermometer that measures beyond one decimal point. This level of precision is necessary to reliably use this method for family planning, and isn’t possible with other basal body thermometers and wearables.

Aside from ultrasound, BBT is the most accurate way to track ovulation.

You can learn more about the intricacies of fertility tracking with BBT in our e-book.

Get reliable predictions

3 ways our devices ensure accuracy (Graphic)

Smart algorithm based on analysis of over 10 million cycles


Easy-to-use trackers that eliminate
the chance of human error


Sensitive sensor calibrated to a certified, traceable international standard
to provide an accurate reading to the 100th of a degree.

 

KEY SCIENTIFIC FINDINGS

Supported by decades of independent clinical research

99.4% accurate

Based on a 10-year analysis of 107,000 cycles, scientists confirmed that Valley’s algorithm distinguishes between non-fertile and fertile days with 99.4% accuracy.

See study
Detect ovulation with clinical reliability

Research presented at the International Meeting on Infertility and Assisted Reproductive Technology showed that Valley devices detect ovulation with similar results to ultrasound and hormone tests.

4.5 months

A 3-year study with 686 women found that 81% of those who wanted to get pregnant were successful. Conception often happened in the very first cycle, and the average time to conceive was 4.5 months.

0.5% unintended pregnancies

Following results from a 2016 study with 3,450 women, gynecologists concluded they can safely recommend our devices for women who cannot or choose not to take hormones.

See study

“The high measurement accuracy of the temperature sensors and the precise algorithm of thetemperature  calculation provide a high degree in method safety, which clearly stands out from competitive devices.” 

– Medical Evaluation, Dr. Andreas Marx

Not all cycle trackers are created equal

Here’s what sets our devices apart.

1️⃣ Registered medical device

Not every fertility tracker meets the standards for medical devices, which are subject to quality management and frequent regulatory inspections. 

2️⃣ All-in-one fertility tracker

Other cycle trackers require a separate thermometer and app, which can lead to inaccuracies from thermometer calibration or manual transfer of data. Valley devices take your temperature, store your data, and reliably calculate your fertility status in a single device. 

3️⃣ The most sensitive sensor on the market

Unlike other basal body thermometers, ours record only your real - not extrapolated - temperature value to provide the most accurate reading. If cold air enters your mouth during the measurement, the thermometer waits for your temp to stabilize. And provides a reading to the 100th of a degree.

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