Natural Cycles USA Corp, New York, New York, USA.
Department of Clinical Sciences at Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden.
J Womens Health (Larchmt). 2021 Jun;30(6):782-788. doi: 10.1089/jwh.2020.8547. Epub 2020 Dec 23.
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. 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). 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. 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).
基于数字化生育意识的避孕方法对于现代女性来说，是一种有吸引力的荷尔蒙或侵入性避孕方法的替代方案。对于那些可能在未来几年内计划怀孕并希望了解自己个体月经周期的女性来说，它们也很受欢迎。本研究旨在评估 Natural Cycles 应用程序在美国女性群体中预防怀孕的有效性，并描述该应用程序当前用户的主要人口统计学特征。 这项前瞻性真实世界队列研究包括购买年度避孕订阅的用户。通过应用内问卷回答评估人口统计学特征。使用 1 年珍珠指数（PI）和 13 个周期累积妊娠概率（Kaplan-Meier 生命表分析）计算整个队列的避孕效果估计值。 该研究包括 5879 名女性，平均贡献了 10.5 个月的数据，总暴露时间为 5125 名女性年。平均用户年龄为 30 岁，体重指数为 24，报告处于稳定关系中。在典型使用情况下，该应用程序的 13 个周期累积妊娠概率为 7.2%，1 年典型使用 PI 为 6.2。当应用程序在完美使用条件下使用时，PI 为 2.0。 本研究提供的数据深入了解了在美国使用该应用程序的女性群体，并提供了特定国家的有效性估计值。该应用程序的避孕效果与 Natural Cycles 之前公布的数据一致（典型使用时的 PI 为 7，完美使用时的 PI 为 2）。
