Journal of Women's Health (2002), 30(6), 782-788, 2020
Contraceptive Effectiveness of an FDA-Cleared Birth Control App: Results from the Natural Cycles U.S. Cohort
Jack T Pearson, Simon P Rowland, Eleonora Benhar
Berglund Scherwitzl E , Juan Acuna, Gemzell Danielsson K , Kristina Gemzell‐Danielsson, Elina Berglund Scherwitzl , Magda Chelstowska , Kristina Gemzell-Danielsson , Helena Kopp Kallner, Raoul Scherwitzl
Digital fertility awareness-based methods of birth control are an attractive alternative to hormonal or invasive birth control for modern women. They are also popular among women who may be planning a pregnancy over the coming years and wish to learn about their individual menstrual cycle. The aim of this study was to assess the effectiveness of the Natural Cycles app at preventing pregnancy for a cohort of women from the United States and to describe the key demographics of current users of the app in such a cohort.
Materials and Methods
This prospective real-world cohort study included users who purchased an annual subscription to prevent pregnancy. Demographics were assessed through answers to in-app questionnaires. Birth control effectiveness estimates for the entire cohort were calculated using 1-year pearl index (PI) and 13-cycle cumulative pregnancy probability (Kaplan-Meier life table analysis).
Results
The study included 5879 women who contributed an average of 10.5 months of data for a total of 5125 woman-years of exposure. The average user was 30 years old with a body mass index of 24 and reported being in a stable relationship. With typical use, the app had a 13-cycle cumulative pregnancy probability of 7.2% and a 1-year typical use PI of 6.2. When the app was used under perfect use, the PI was 2.0.
Conclusions
The data presented in this study give insights into the cohort of women using this app in the United States, and provide country-specific effectiveness estimates. The contraceptive effectiveness of the app was in line with previously published figures from Natural Cycles (PI of seven for typical use and two for perfect use).
Natural Cycles app contraceptive effectiveness United States, digital fertility awareness based method birth control, FDA cleared birth control app pearl index, Natural Cycles typical use perfect use pregnancy rates, fertility awareness app prospective cohort study, Kaplan Meier cumulative pregnancy probability contraception, pearl index calculation real world contraceptive effectiveness, digital health technology family planning effectiveness, basal body temperature app contraceptive method, Pearson Natural Cycles US cohort contraception study, FABM app-based method typical use failure rate
PMID 33370220 33370220 DOI 10.1089/jwh.2020.8547 10.1089/jwh.2020.8547
Cite this article
Pearson, J. T., Chelstowska, M., Rowland, S. P., Benhar, E., Kopp-Kallner, H., Berglund Scherwitzl, E., Acuna, J., Gemzell Danielsson, K., & Scherwitzl, R. (2021). Contraceptive Effectiveness of an FDA-Cleared Birth Control App: Results from the Natural Cycles U.S. Cohort. Journal of women's health (2002), 30(6), 782-788. https://doi.org/10.1089/jwh.2020.8547
Pearson JT, Chelstowska M, Rowland SP, Benhar E, Kopp-Kallner H, Berglund Scherwitzl E, et al. Contraceptive Effectiveness of an FDA-Cleared Birth Control App: Results from the Natural Cycles U.S. Cohort. J Womens Health (Larchmt). 2021;30(6):782-788. doi:10.1089/jwh.2020.8547
Pearson, J. T., et al. "Contraceptive Effectiveness of an FDA-Cleared Birth Control App: Results from the Natural Cycles U.S. Cohort." Journal of women's health (2002), vol. 30, no. 6, 2021, pp. 782-788.
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