Period tracker applications: What menstrual cycle information are they giving women?

Abstract

Background: Period tracking applications (apps) allow women to track their menstrual cycles and receive a prediction for their period dates. The majority of apps also provide predictions of ovulation day and the fertile window. Research indicates apps are basing predictions on assuming women undergo a textbook 28-day cycle with ovulation occurring on day 14 and a fertile window between days 10 and 16. Objective: To determine how the information period tracker apps give women on their period dates, ovulation day and fertile window compares to expected results from big data. Methods: Five women’s profiles for 6 menstrual cycles were created and entered into 10 apps. Cycle length and ovulation day for the sixth cycle were Woman 1—Constant 28 day cycle length, ovulation day 16; Woman 2—Average 23 day cycle length, ovulation day 13; Woman 3—Average 28 day cycle length, ovulation day 17; Woman 4—Average 33 day cycle length, ovulation day 20; and Woman 5—Irregular, average 31 day cycle length, ovulation day 14. Results: The 10 period tracker apps examined gave conflicting information on period dates, ovulation day and the fertile window. For cycle length, the apps all predicted woman 1’s cycles correctly but for women 2–5, the apps predicted 0 to 8 days shorter or longer than expected. For day of ovulation, for women 1–4, of the 36 predictions, 3 (8%) were exactly correct, 9 predicted 1 day too early (25%) and 67% of predictions were 2–9 days early. For woman 5, most of the apps predicted a later day of ovulation. Conclusion: Period tracker apps should ensure they only give women accurate information, especially for the day of ovulation and the fertile window which can only be predicted if using a marker of ovulation, such as basal body temperature, ovulation sticks or cervical mucus.

A survey of women’s experiences of using period tracker applications: Attitudes, ovulation prediction and how the accuracy of the app in predicting period start dates affects their feelings and behaviours

“… 10 This is supported by Zwingerman et al, 11 whose appraisal of menstrual tracking apps showed 22.1% of apps to contain serious inaccuracies. A study by Worsfold et al 12 analyzed the ability of period tracker apps to accurately predict the length and dates of five different cycle profiles representing a range of real-life cycles. They found variation between apps in their prediction of fertile days, day of ovulation and period start dates.…”

Analysis of the menstrual chart observation characteristics, meeting the typical cycle criteria among women of procreation age according to the symptom-thermal double-check method

“…28.4 days was the length recorded by Tawara (Tawara, et al, 2012). In the study by Worsfold et al conducted on a very small group, one woman reported regular menstrual cycles lasting 28 days, one woman had irregular cycles with the mean length of 31 days, and in three other women cycles varied from 23 to 33 days on average (Worsfold, et al, 2021). In the WHO study, the average duration of menstrual cycles was 28.5 days (World Health Organization: A prospective multicentre trial of the ovulation method of natural family planning, 1983).…”

“…The mean duration of highly fertile mucus in our study approached 4 days. In the study by Worsfold et al, highly fertile mucus continued for 6 days (Worsfold, et al, 2021). In the study by Najmabadi et al, the average number of days of highly fertile mucus per cycle during a year was 6.4 days (Najmabadi, et al, 2021).…”

“…A study from 2017 examined 284 women and analysed 1635 cycles (Crawford, Pritchard, Herring, 2017). The 2021 study was conducted with the participation of five women who provided data on 30 cycles (Worsfold, Marriott, Johnson, Harper, 2021). In the same year, 528 women participated in a study with 2488 cycles analysed (Najmabadi, Schliep, Simonsen, Porucznik, Egger, Stanford, 2021).…”

The popularity and usability of mobile applications for women and expecting mothers

“…With many women using period tracker apps, it gives the ideal opportunity for women to have a platform to learn about their menstrual cycle health. 6 Women highly appreciated evidence-based information, expert opinions, and tailored advice available on the apps. Efforts should be made by health professionals, app developers, and policymakers to ensure quality apps be developed for providing timely health promotion information.…”