Menstrual characteristics are important signs of women's health. Here we examine the variation of menstrual cycle length by age, ethnicity, and body weight using 165,668 cycles from 12,608 participants in the US using mobile menstrual tracking apps. After adjusting for all covariates, mean menstrual cycle length is shorter with older age across all age groups until age 50 and then became longer for those age 50 and older. Menstrual cycles are on average 1.6 (95%CI: 1.2, 2.0) days longer for Asian and 0.7 (95%CI: 0.4, 1.0) days longer for Hispanic participants compared to white non-Hispanic participants. Participants with BMI ≥ 40 kg/m2 have 1.5 (95%CI: 1.2, 1.8) days longer cycles compared to those with BMI between 18.5 and 25 kg/m2. Cycle variability is the lowest among participants aged 35-39 but are considerably higher by 46% (95%CI: 43%, 48%) and 45% (95%CI: 41%, 49%) among those aged under 20 and between 45-49. Cycle variability increase by 200% (95%CI: 191%, 210%) among those aged above 50 compared to those in the 35-39 age group. Compared to white participants, those who are Asian and Hispanic have larger cycle variability. Participants with obesity also have higher cycle variability. Here we confirm previous observations of changes in menstrual cycle pattern with age across reproductive life span and report new evidence on the differences of menstrual variation by ethnicity and obesity status. Future studies should explore the underlying determinants of the variation in menstrual characteristics.
PMID 37248288 37248288 DOI 10.1038/s41746-023-00848-1 10.1038/s41746-023-00848-1 Li et al. 2023, Li 2023
Cite this article
Li, H., Gibson, E. A., Jukic, A. M. Z., Baird, D. D., Wilcox, A. J., Curry, C. L., Fischer-Colbrie, T., Onnela, J. P., Williams, M. A., Hauser, R., Coull, B. A., & Mahalingaiah, S. (2023). Menstrual cycle length variation by demographic characteristics from the Apple Women's Health Study. NPJ digital medicine, 6(1), 100. https://doi.org/10.1038/s41746-023-00848-1
Li H, Gibson EA, Jukic AMZ, Baird DD, Wilcox AJ, Curry CL, Fischer-Colbrie T, Onnela JP, Williams MA, Hauser R, Coull BA, Mahalingaiah S. Menstrual cycle length variation by demographic characteristics from the Apple Women's Health Study. NPJ digital medicine. 2023;6(1):100. doi:10.1038/s41746-023-00848-1
Groenman AP et al., 2022·Autism : the international journal of research and practice
Autism spectrum conditions were once seen as a predominantly male condition, but this has caused research to have little focus on women. Therefore, little is known about menstruation and menopause in autism spectrum conditions. Some smaller studies indicate that autistic individuals might suffer from increased difficulties surrounding these events. This study aimed to investigate whether autistic women experience more frequent premenstrual dysphoric disorder, causing extreme physical, emotional, and functional impairment. In a partly overlapping sample, we also examined whether women with autism spectrum condition experience increased complaints surrounding menopause. We did not find an increased prevalence of premenstrual dysphoric disorder in autism spectrum conditions (14.3%) compared with non-autistic women (9.5%). Those with autism spectrum conditions did experience increased menopausal complaints. These menopausal complaints were associated with higher levels of depression and autistic traits. In non-autistic women, menopausal complaints were associated with increased inattention, hyperactivity/impulsivity (i.e. attention deficit hyperactivity disorder traits), and depression. With this work, we show the important role that major reproductive milestones can have in an autistic woman's life.
Jerilynn C Prior et al., 2011·Front Biosci (Schol Ed)·
Perimenopause, rather than a time of declining estrogen, is characterized by three major hormonal changes that may begin in regularly menstruating women in their mid-thirties: erratically higher estradiol levels, decreased progesterone levels (in normally ovulatory, short luteal phase or anovulatory cycles), and disturbed ovarian-pituitary-hypothalamic feedback relationships. Recent data show that approximately a third of all perimenopausal cycles have a major surge in estradiol occurring de novo during the luteal phase. This phenomenon, named "luteal out of phase (LOOP)" event, may explain a large proportion of symptoms and signs for symptomatic perimenopausal women. Large urinary hormone data-sets from women studied yearly over a number of years in the Study of Women Across the Nation (SWAN) and in the Tremin data will eventually provide a more clear prospective understanding of within-woman hormonal changes. Predicting menopause proximity with FSH or Inhibin B levels is documented to be ineffective. Anti-Mullerian hormone levels may prove predictive. Finally, there is an urgent need to change perimenopause understandings, language and therapies used for midlife women's symptoms to reflect these hormonal changes.
There are many types of ovarian activity that occur in women. This review provides information on the relationship between the hormone values and the degree of biological response to the hormones including the frequency and degree of uterine bleeding. The continuous process is termed the 'Continuum' and is thus similar to other processes in the body. This review draws on information already published from monitoring ovarian activity by urinary oestrogen and pregnanediol measurements using timed 24-h specimens of urine. Much of the rationalization was derived from 5 to 6 year studies of girls progressing from childhood to adulthood, women progressing through menopause, and the return of fertility post-partum. During these times, all the reported types of ovarian activity were encountered. All cycle types can be understood in terms of steps in the normal maturation of fertility at the beginning of reproductive life, its return post-partum and its demise at menopause. Each step merges into the next and therefore the sequence is termed the 'Continuum'. Unpredictable movement from fertile to infertile types and back can occur at any time during reproductive life. Stress is a major causative factor. Hormonal definitions for each step, the relevance of the various cycle types in determining fertility and in the initiation of uterine bleeding and the roles of the pituitary hormones in causing them, are presented. The findings explain the erratic fertility of women and why ovulation is not always associated with fertility. They provide an understanding of the various types of ovarian activity and their relation to pituitary function, fertility and uterine bleeding.
The purpose of this review is to put into a useful clinical context the changing over time of basic ovarian-pituitary-hypothalamic relationships during perimenopause. "Perimenopause" means changes in ovarian hormones, feedback relationships, and clinical experiences beginning in women ages 35-50 with regular flow and ending 1 yr after the final menstrual flow. A key observation must be explained--estradiol levels are increased in perimenopause. Inhibin B levels are lower and activin may be higher in midlife, menstruating women. These changes probably cause higher follicular phase FSH levels--"endogenous ovarian hyperstimulation" results. The positive estradiol feedback on LH is also disturbed--midcycle LH peaks and mid-luteal slow-frequency, high-amplitude LH pulses are less frequent. In addition to higher levels, estradiol receptors may increase in tissues of symptomatic women. Despite hyperstimulation of follicles, progesterone levels and luteal phase lengths are paradoxically decreased--reasons probably include LH peak disruptions and estrogen-stimulated greater corticotrophin-mediated reproductive suppression. In summary, disturbed feedback relationships causing higher and unpredictable estrogen and lower progesterone levels occur throughout perimenopause, especially during regular cycles. Prospective, population-based research is needed to systematically relate these feedback hormonal changes to clinical characteristics and to allow a diagnosis of perimenopause in regularly cycling midlife women.