Chapter 185 - The Menstrual Cycle, Sleep, and Circadian Rhythms

Abstract

Women experience monthly variations in reproductive hormones throughout their reproductive years. These hormonal variations can influence sleep and circadian rhythms, and in turn, sleep impacts reproductive physiology in pubertal girls and women. The menstrual cycle is associated with changes in body temperature rhythms and sleep architecture, most notably a blunted amplitude of the body temperature rhythm, increased spindle frequency activity during sleep, and reduced rapid eye movement (REM) sleep in the luteal phase compared with the follicular phase. There are strong circadian and sleep influences on reproductive hormones that vary depending on pubertal stage and age. Luteinizing hormone (LH) pulse initiation is uncommon during REM sleep, and amplification of pulsatile LH secretion is strongly linked with sleep in pubertal girls (and boys), with slow wave sleep seeming to encourage LH pulse initiation. In contrast, LH pulse frequency slows with sleep in adult women during the follicular phase, with pulse initiation tending to follow brief awakenings. Also, the LH surge that provokes ovulation is under circadian control, at least in some mammalian species. The interaction between reproductive function and sleep and circadian rhythms is apparent from studies in female shift workers, who are more likely to have menstrual-related disturbances. Menstrual-related disorders are also linked with altered sleep; for example, women with polycystic ovary syndrome are at risk for developing sleep-disordered breathing, which may contribute to insulin resistance and other metabolic abnormalities. Women with severe premenstrual syndrome or dysmenorrhea (painful menstrual cramps) may have transient sleep disturbances or insomnia, coupled with their other mood and/or physical symptoms before and during menstruation. Assessment of sleep complaints in women should include an investigation of any association between symptoms and menstrual cycle phase or menstrual-related disorders.