Perimenopause, a complex physiological transition for midlife women, begins with changes in experiences many years before cycles become irregular, oestradiol levels decrease or follicle-stimulating hormone levels increase. Erratic and average higher oestradiol levels as well as shorter luteal phase lengths and lower progesterone levels occur during perimenopause. These ovarian changes may be causally related to lower inhibin production but the dynamic prospective inter-relationships within women are not well documented. This review will first define perimenopause and then explore the limited published data on ovulatory characteristics in perimenopause. In addition, it will report preliminary prospective observational data on menstrual cycles and ovulation in initially ovulatory women followed through the perimenopause. Prospective data suggest that ovulation disturbances begin early in perimenopause and increase with irregular cycles. Combined with higher oestradiol levels they may cause menorrhagia. It is not yet known whether disturbances of ovulation relate to bone loss in perimenopausal, as in premenopausal, women. It is also not known whether progesterone therapy can effectively counteract the end organ (breast, endometrial, brain) effects of higher/erratic oestradiol levels and effectively treat perimenopausal vasomotor and other symptoms.
Prior, J. C. (2002). The ageing female reproductive axis II: ovulatory changes with perimenopause. Novartis Foundation symposium, 242, 172-192.
Prior JC. The ageing female reproductive axis II: ovulatory changes with perimenopause. Novartis Found Symp. 2002;242:172-192.
Prior, J. C. "The ageing female reproductive axis II: ovulatory changes with perimenopause." Novartis Foundation symposium, vol. 242, 2002, pp. 172-192.
Related articles
Cycle Across the Lifespan · Cycle and General Health
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.
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.
Women have twice the incidence of major depression compared with men. They are prone to develop episodes of depression during times of reproductive hormonal change at puberty, with use of oral contraceptives, during the premenstrual phase of the menstrual cycle, postpartum and during the perimenopause (see review: ). describes the variety of disturbances in biological rhythms observed in mood disorders. In this report, we describe the chronobiological disturbances observed in female-specific mood disorders, namely, premenstrual dysphoric disorder, pregnancy and postpartum depression and menopause. We hypothesize that changing reproductive hormones, by affecting the synchrony or coherence between components of the circadian system, may alter amplitude or phase (timing) relationships and thereby contribute to the development of mood disorders in predisposed individuals.
Cycle Across the Lifespan · Cycle and General Health
Bouchard TP et al., 2026·Journal of ovarian research·
Open Access
Reproductive hormones of the fertile window are often referenced to women in regular cycles, but this may not be representative of the hormonal profiles of women in different circumstances like polycystic ovarian syndrome, the postpartum period, and the perimenopause transition. This observational cohort study sought to identify the variability in the reproductive hormones in various clinical circumstances and to establish potential thresholds for each category based on hormone measurements with the Mira urinary hormone monitor. A total of 57 women (ages 22-51) in various circumstances (regular cycles, polycystic ovarian syndrome, postpartum and perimenopause) tracked Mira urine hormone measurements (estrone-3-glucuronide, luteinizing hormone, pregnanediol glucuronide), contributing 444 cycles of data. Using additive mixed models, hormone values were stratified by the four different reproductive categories. The perimenopause and polycystic ovarian syndrome groups demonstrated relative hypoestrogenic states, while the perimenopause group showed low luteal pregnanediol glucuronide and the polycystic ovarian syndrome/polyendocrine metabolic ovarian syndrome (PCOS/PMOS) group showed high luteal pregnanediol glucuronide. The perimenopause group had significantly higher luteinizing hormone values throughout the whole cycle. The fertile window hormone thresholds vary depending on a woman's specific reproductive category. Women in different circumstances should not necessarily use the same hormonal thresholds for the fertile window and ovulation. A larger dataset with ultrasound correlation to ovulation is required to delineate the fertile window with more precision. Hormone differences across the menstrual cycle could be used for targeted treatments in polycystic ovarian syndrome and perimenopause women.