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Here at Ava, we take data—especially fertility and pregnancy data—very seriously. Our team is led by premier data scientists, obstetricians, gynecologists, and reproductive endocrinologists, many of whom hold Ph.D.’s and decades of experience in their respective fields. So, when you read content on AvaWorld, you can trust that it’s backed by science and has been thoroughly researched and vetted by our experts.
See Five Fertile Days Per CycleDouble your chances to get pregnant with Ava*
There are only six days per month when it’s possible to conceive, and Ava is clinically proven to recognize five of them.
Unlike LH tests, which only give you one or two fertile days, Ava gives you and your partner more time for babymaking.track your fertility
Tracks your fertile window in real time
Unlike the temperature method, which only tells you when you’ve already ovulated and are no longer fertile, Ava can detect the beginning of the fertile window in real time.
Easy to use
With Ava, there’s no need to wake up early to take your temperature or remember to pee on a stick.
Just wear it at night and sync with the app in the morning to see your fertility status in real time.
Track your temperature, sleep, stress, and resting heart rate
In addition to fertility detection, Ava also tracks temperature, sleep quality and quantity, physiological stress levels, and resting pulse rate—so you can make sure you’re in a good place to make a baby.
What Ava can measure
- SKIN TEMPERATURE
- RESTING PULSE RATE
- BREATHING RATE
- HEART RATE VARIABILITY RATIO
The temperature of your skin at your wrist.
Skin temperature is one of the signals Ava uses to identify your fertile window. It rises by about one half of a degree after ovulation, and remains elevated until your next period begins. During pregnancy, temperature remains elevated. If you’ve ever tracked your basal body temperature orally, you’ll notice that Ava’s temperature reading is several degrees lower than your oral temperature. It’s normal for skin temperature to be lower than oral temperature, but we found that it exhibits the typical biphasic pattern during the cycle.
If you’ve ever tracked your basal body temperature orally, you’ll notice that Ava’s temperature reading is several degrees lower than your oral temperature. It’s normal for skin temperature to be lower and more variable than oral temperature.
Average skin temperature readings (when taken at a room temperature of 64.5 – 77 degrees Fahrenheit) are between 90.5 – 98.2 degrees Fahrenheit.
Average skin temperature readings (when taken at a room temperature of 18 – 25 degrees Celsius) are between 32.5 – 36.8 degrees Celsius.
How often your heart beats per minute at rest.
Scientific literature shows that resting pulse rate is lower during the follicular phasethan the luteal phase. Ava’s clinical research partner, the University Hospital of Zurich, identified further variation in resting pulse rate throughout the menstrual cycle: resting pulse rate rose by about 2.1 beats per minute at the beginning of the fertile window.
During pregnancy, resting pulse rate remains elevated.
Typical resting pulse rates are between 40 and 80 bpm. If you are very physically active, your resting pulse rate may be even lower than 40 bpm. Stress, illness, and alcohol can cause temporary increases in resting pulse rate.
Rate of respiration per minute.
Scientific literature shows that breathing rate is higher in the luteal phase than in the follicular phase. Breathing rate can vary widely during the course of a day due to your activities, but typical breathing rates during sleep are much more stable, and range from 10 – 25 bpm.
The lower your HRV ratio, the less stressed you are.
HRV is the variation in the time interval from one heartbeat to the next. It can be used as an indicator of physiological stress: when there is a lot of variation in the time interval between heartbeats—high HRV—it means you are more resilient and less stressed. Ava measures the ratio between low frequency and high frequency waves in your heart rate. Because Ava measures HRV using this ratio, a lower number means you are less stressed.
Normal HRV ratio varies widely from person to person, but by looking for an increase or decrease from your baseline HRV ratio, you can learn about your body’s physiological stress level.
The process of supplying blood to the tissues of your body.
As blood flows through your capillaries, it delivers nutrients to the tissues and helps sweep away waste. Then, the blood flows back to the heart, and begins the process all over again.
If you’ve ever had an elastic band around your finger and felt the blood flow being cut off, you’re already familiar with the process of perfusion. While you can limit perfusion with an elastic band, perfusion can also change naturally for different reasons. For example, your perfusion changes in order to keep you warm or cool you down. Perfusion also changes in relation to the menstrual cycle: it is lowest at the start of the fertile window and highest in the luteal phase.
Ava tracks your movement with an accelerometer.
This parameter allows Ava to distinguish between light and deep + REM sleep.
Total sleep hours and ratio of light to deep + REM sleep.
The quality and quantity of sleep you’re getting each night are important parameters to track for your fertility. Your menstrual cycle can affect your sleep, and your sleep, in turn, can affect your menstrual cycle. Pregnancy can also influence sleep.
Ava records the amount of sleep you get each night. Additionally, Ava tracks the percentage of combined deep and REM sleep. Deep sleep is important for feeling rested the next morning, while REM sleep is important for learning and storing memories.
Typical sleep cycles for adults include 50 – 65 percent light sleep and 35 – 50 percent deep sleep + REM.