OvuSense vs Ava

When it comes to fertility tracking, the importance of accurate and real-time data cannot be overstated. Two products that have made significant strides in this field are OvuSense and Ava. Each offers a unique approach to tracking ovulation and fertility, but how do they compare?

Let's take a look.

What is OvuSense?

OvuSense is a fertility and ovulation monitor that predicts your ovulation using current cycle data and both predicts then confirms your ovulation. It does this by tracking continuous core body temperature through a vaginal device that is inserted and worn overnight with its OvuSense Advanced Fertility Monitor product.

The vaginal sensor is worn overnight and monitors fluctuations in progesterone levels throughout your cycle - this data is then synced to the OvuSense App in the morning via harmless NFC (the same connection contactless credit cards use).

This method provides a more accurate picture of your ovulation timing than traditional Basal Body Temperature monitoring devices, which rely on oral temperature measurements.

Furthermore, OvuSense has been clinically proven to provide 99% accuracy for confirming ovulation [a] plus 96% positive predictive value for predicting ovulation [a]. OvuSense offers an 8-day fertile window for women with regular or irregular cycles of any length, making it an invaluable tool for those trying to conceive.

What is Ava?

Ava is another well-known brand that offers a wrist-worn device to monitor various physiological parameters such as skin temperature, heart rate, and breathing rate to predict fertility. Ava's device is also worn overnight and syncs to an App in the morning, giving a 5-day fertile window for planning conception.

In terms of accuracy, Ava does not publish this information clearly on their website however the published clinical research indicates 78% accuracy for confirming ovulation and does not predict ovulation in advance. Ava offers a 5-day fertile window and is only marketed for women with cycle lengths of 24-35 days.

OvuSense vs Ava: Features comparison

Features OvuSense Ava
Type of Device Vaginal Sensor Wristband
Tracking Method Core body temperature Skin temperature
Ovulation Prediction Yes No
Ovulation Confirmation Yes Yes
Prediction Accuracy 96% [a] N/A
Confirmation Accuracy 99% [a] 78% (estimate, not published publicly)
Fertile Window 8 days 5 days
Irregular Cycles & PCOS Friendly Yes No
Clinically Backed Yes, multiple clinical trials Yes, 1 clinical trial
FDA Approved Yes, since 2013 Yes, since 2021
Compatibility iOS and Android iOS and Android
Sensor Connectivity NFC Bluetooth
Money-back Guarantee 90 days ovulation promise 6-12 months if you don't get pregnant (extra payment required, US-only)
Pricing Model One-time purchase or Subscription-based service One-time purchase
Price $279 - $399 one-time or $35/month ($99 up front) $279 - $359 one time

When comparing OvuSense and Ava, the most apparent difference lies in their methods of data collection. While OvuSense uses a vaginal sensor to track core body temperature and progesterone levels, Ava uses a wristband to monitor skin temperature and various physiological parameters.

In terms of accuracy, OvuSense has a 99% accuracy for confirming ovulation [a] plus 96% positive predictive value for predicting ovulation [a]. Ava has not publicly disclosed its accuracy rate for confirming ovulation (which we calculate from published clinical research to be 78%) and makes no claim to be able to predict ovulation.

OvuSense provides a larger fertile window (8 days) than most devices, which could be crucial for couples trying to conceive. On the other hand, Ava provides daily fertility updates, giving users a broader perspective on their overall fertility health.

Ava is marketed for women with cycle lengths of 24-35 day, making it unsuitable for those with irregular cycles or PCOS. OvuSense is marketed and clinically proven for women with all cycle types, including PCOS.

Finally, comfort and ease of use might be a deciding factor for some women. Ava's wrist-worn device could be seen as less intrusive compared to OvuSense's vaginal sensor. However, this ultimately depends on personal preference (OvuSense also offer the OvuSense Flex fertility monitor which includes a skin-worn sensor - this is not part of this comparison though).


Both OvuSense and Ava offer innovative solutions for fertility tracking. The choice between the two would depend on individual preferences for comfort, the level of detail desired, and the emphasis on accuracy.


[a] The accuracy of ovulation confirmation by OvuSense is based on the data set originally published at the 2013 ASRM meeting as a quality index: Papaioannou S, Aslam M (2013), and developed in the key publication outlining the accuracy and positive predictive value of advance prediction of ovulation shown at the 2014 ESHRE meeting: Papaioannou S, Delkos D, Pardey J (2014).