JMIR Publications

ABSTRACT

Background:

Despite its importance to female reproductive health and its impact on women's daily lives, the menstrual cycle, its regulation, and its effects on health remain poorly studied. As conventional clinical trials rely on infrequent in-person assessments, digital studies with wearable devices enable the collection of longitudinal subjective and objective measures.

Objective:

The aim of this study was to explore the technical feasibility of collecting combined wearable and digital questionnaire data and its potential for gaining biological insights on the menstrual cycle.

Methods:

This prospective observational cohort study was conducted online over 12 weeks. 42 biological women were recruited by their local gynecologist in Berlin, Germany, and received a Fitbit inspire 2 device and access to a study app with digital questionnaires. Statistical analysis included descriptive statistics on user behavior and retention, as well as a comparative analysis of symptoms from the digital questionnaires with metrics from the sensor devices at different phases of the menstrual cycle.

Results:

The average time spent in the study was 63.3 (±33.0) days with nine out of 42 individuals dropping out within two weeks of study start. We collected partial data of 114 ovulatory cycles from 33 participants with complete data from a total of 50 cycles. Participants reported a total of 2,468 symptoms in the daily questionnaires that were asked during the luteal phase and menses. Despite difficulties with data completeness, the combined questionnaire and sensor data collection was technically feasible and produced interesting biological insights. We observed an increased heart rate in the mid and end luteal phase compared to menses and participants with strong PMS were walking significantly fewer steps (average daily step count 10,283 ±6,277) during the luteal phase and menses compared to participants with no/low PMS (11,694 ±6,458).

Conclusions:

We demonstrate the feasibility of using an app-based approach for collecting combined wearable device and questionnaire data on menstrual cycles. Dropouts in the first study weeks showed that engagement efforts would need to be improved for larger studies. Despite the challenges faced in collecting wearable data on consecutive days, the collected data provided valuable biological insights, suggesting that the use of questionnaires in conjunction with wearable data may provide a more complete understanding of the menstrual cycle and its impact on daily life. The biological findings should motivate further research in understanding the relationship between the menstrual cycle and objective physiological measurements from sensor devices.