Basal Temperature Measurement Using a Multi-Sensor Armband in Australian Young Women: A Comparative Observational Study

Abstract

BackgroundThe menstrual cycle is a key marker of health in women of reproductive age. Monitoring ovulation is useful in health studies involving young women. The upward shift in basal body temperature, which occurs shortly after ovulation and continues until the next menses, is a potentially useful marker of ovulation, which has been exploited in clinical and research settings.ObjectiveWe investigated the utility of BodyMedia SenseWear (BMSW) in monitoring ovulation in young women by analyzing the correlation and agreement of basal temperatures measured using BMSW and a digital oral thermometer.MethodsKappa statistics were used to determine the agreement in ovulation detection between the two devices, for each participant, under each form of analysis. Participants also completed an online questionnaire assessing the acceptability of both devices.ResultsWe recruited 16 participants with 15 of them providing analyzable data (11 OCP non-users, 4 OCP users). Weak to moderate correlations were observed between thermometer and BMSW temperature measurements averaged over 5 different time intervals. However, no agreement between methods was observed using Bland-Altman plots. There was a significant difference in the range of temperatures that each device recorded (thermometer: 35.3-37.2°C, BMSW: 29.7-36.7°C) with BMSW temperatures significantly lower than thermometer temperatures: mean 34.6°C (SD 1.2) versus 36.4°C (SD 0.3) respectively, P<.001. Poor agreement was observed between devices under quantitative analysis of ovulation while fair agreement was observed under visual analysis. Under both quantitative and visual analysis, there was 0% agreement for evidence of ovulation.ConclusionsThis study demonstrated the importance of evaluating biomeasures collected using mobile monitoring devices by comparison with standard methods. It revealed a relatively poor correlation between BMSW and oral thermometer temperature readings and suggested that BMSW is unlikely to detect an upward shift in basal body temperature. Participant behavior suggested poor compliance in the use of BMSW for basal temperature measurement and that the basal body temperature method may not be suitable for use in unselected samples of young women. There is a need for research tools for monitoring ovulation that are simple, self-administered, and inexpensive, yet appealing to young women.

The Accuracy of Wrist Skin Temperature in Detecting Ovulation Compared to Basal Body Temperature: Prospective Comparative Diagnostic Accuracy Study

“…Krauchi et al [4] reported a similar pattern of temperature changes in a menstrual cycle between BBT and skin temperature. In contrast, Wark et al [13] reported poor agreement between BBT and the mean upper arm skin temperature measured at 10-, 30-, 60-, 90-, and 120-minute intervals before waking.…”

“…After the initial test, the participant continued doing the LH test daily until a positive result, which was shown as a stable smiling face symbol on the device, or until the next menstruation. A positive result indicates an LH surge, which typically occurs 1 day before ovulation [13]. Participants reported the LH test results in the dedicated field of their Ava app.…”

“…This explains why it detected more temperature shifts than BBT. Few studies have compared the two temperature curves [4,13]. Krauchi et al [4] reported a similar pattern of temperature changes in a menstrual cycle between BBT and skin temperature.…”

“…In addition, lifestyle factors may strongly influence the reliability of this method [6]. A number of devices offering continuous temperature measurements at different body sites have been developed over the past decade [7][8][9][10][11][12][13]. In our previous studies, we have shown that continuously measured wrist skin temperature during sleep also presented a biphasic pattern in menstrual cycles, with 82% of the observed cycles having a sustained 3-day temperature shift [9,12].…”

Development of a permanent device for fertility period detection by basal body temperature and analysis of the cervical mucus potential of hydrogen

“…It should be noted, however, the days when the temperature would have been influenced by other events such as illness, medication, or a sleepless night. [ 10 11 ]…”