Ava
Ava Fertility Tracking Bracelet
7.7/10 overallAround £249 one-off for the bracelet
A wearable worn overnight that tracks multiple physiological signals to predict the fertile window, without needing daily test strips or wands.
Ava is a wrist-worn sensor rather than a urine-based test or manual temperature reading — it tracks skin temperature, resting pulse, breathing rate and other signals overnight and uses the pattern to predict your fertile window a few days in advance, differing meaningfully from Femometer's single-metric basal thermometer already in this category. The advantage is passive data collection: no test strips, no daily readings to remember, just wearing the bracelet to sleep.
Against Natural Cycles' clinically-validated temperature approach also in this category, Ava predicts forward (giving advance notice of the fertile window) rather than confirming after the fact, which some find more useful for planning. The trade-off is a higher upfront cost for the wearable itself, and reliance on consistent overnight wear for the algorithm to build an accurate picture.
What we liked
- Fully passive tracking, no daily test strips or wands needed
- Predicts the fertile window in advance rather than after ovulation
- Tracks multiple physiological signals for a fuller picture
Where it falls short
- High one-off cost for the wearable
- Needs consistent overnight wear to build an accurate profile
- Prediction-based rather than a direct hormone confirmation
Specs
- Format
- Wrist-worn bracelet + companion app
- Charging
- Rechargeable, worn overnight
- Data collection
- Passive, no daily test strips
- Tracking method
- Multi-signal overnight wearable (temperature, pulse, breathing)
- Prediction window
- Advance fertile window prediction, typically 5 days
How we scored it
Prediction Accuracy
How reliably the tool identifies or confirms the fertile window.
Multi-signal overnight tracking gives good advance prediction, though not a direct hormone confirmation.
Ease of Daily Use
How simple it is to fit into a daily routine.
Fully passive — no daily test strips or manual readings needed.
Value for Money
Subscription or purchase cost relative to what you get.
High one-off cost, though no ongoing consumable expense unlike wand-based monitors.
Weighted by importance for this category — see our editorial policy for how we test.
The alternative
Femometer
Vinca Bluetooth Basal Body Thermometer
Measures to 1/100th degree accuracy and syncs to an app to chart temperature-based ovulation confirmation.