Accuracy of an Overnight Axillary-Temperature Sensor for Ovulation Detection: Validation in 194 Cycles

Area of Science:

• Reproductive endocrinology
• Biomedical engineering
• Women's health technology

Background:

• Reliable identification of ovulation and the fertile window is crucial for family planning and reproductive health.
• While various temperature monitoring methods exist, data on axillary temperature wearable devices is limited.

Purpose of the Study:

• To assess the accuracy of an axillary temperature armband sensor (Tempdrop) in identifying ovulation day and the fertile window.
• To compare the Tempdrop sensor's performance against a reference method, the Clearblue Connected Ovulation Test System.

Main Methods:

• Analysis of 194 cycles from 125 women (April 2023 - June 2024).
• Utilized the Clearblue Connected Ovulation Test System as the reference standard for ovulation confirmation.

Main Results:

• High performance parameters were observed: sensitivity (96.8%), specificity (99.1%), accuracy (98.6%), positive predictive value (96.8%), and negative predictive value (99.1%).
• Demonstrated a clear and significant temperature shift around the time of ovulation.
• The device provides a distinct temperature curve for luteal phase quality assessment.

Conclusions:

• The axillary temperature wearable sensor (Tempdrop) is an effective tool for determining ovulation timing.
• It serves as a viable alternative to traditional urine ovulation tests.
• Offers additional benefits by providing a clear temperature curve for evaluating luteal phase quality.