Nomenclature and endocrinology of menopause and perimenopause

Abstract

The early and late perimenopausal transition is characterized by changing cycle length as well as by menopausal symptoms in some women, including increasing hot flashes and night sweats. Breast tenderness decreases as women enter the late transition. This review, as part of the clinical reviews on the menopausal woman with comorbidity, covers the endocrine phenomena of perimenopause, terminology and the observed clinical characteristics of the transition. It should be noted that the definitions covering this period vary between publications. The average duration of perimenopause is approximately 5 years. The earliest detectable hormonal change is a fall in ovarian secretion of inhibin B, with a subsequent rise in follicle-stimulating hormone and maintained or increased levels of estradiol. As women transit the perimenopause, cycle irregularity increases, with the more frequent occurrence of prolonged ovulatory and anovulatory cycles. Levels of follicle-stimulating hormone and estradiol fluctuate increasingly and luteal function declines. Vasomotor symptoms tend to be most frequent around the time of final menses. The perimenopause is thus a time of cycle and hormone variability and single hormone measurements provide little useful information, with the clinical history being the most appropriate method of assessing menopausal status. This information will be very helpful to the clinician treating the concerned and symptomatic patient. It will also aid clinicians to avoid unnecessary laboratory testing and help them educate their patients about their perimenopause.