Apple’s Women’s Health Study set out to identify abnormal uterine bleeding (AUB) patterns and their prevalence in participants and to confirm existing and expected associations between AUB patterns, demographics, and medical conditions. The results are in, have been published in AJOG, and suggest that 16.4% of women in the study experience AUB.
2.9% had irregular menses, 8.4% had infrequent menses, 2.3% had prolonged menses, and 6.1% had spotting. Prevalence of infrequent periods was higher in Black participants and those with class 1, 2, and 3 obesity. Increased prevalence of AUB was noted with class 3 obesity and conditions such as polycystic ovary syndrome, fibroids, thyroid disease, and cervical dysplasia.
How was the study conducted?
Apple Women’s Health Study participants from November 2019 through July 2021 who contributed menstrual tracking data and did not report pregnancy, lactation, use of hormones, or menopause were included in the analysis. Four abnormal uterine bleeding patterns were evaluated: irregular menses, infrequent menses, prolonged menses, and irregular intermenstrual bleeding (spotting). Monthly tracking confirmation using survey responses was used to exclude inaccurate or incomplete digital records. We investigated the prevalence of abnormal uterine bleeding stratified by demographic characteristics and used logistic regression to evaluate the relationship of abnormal uterine bleeding to a number of self-reported medical conditions.