Women and sleep Joan L.F. Shaver, PhD, RN, FAAN* University of Illinois at Chicago, College of Nursing, 845 South Damen, Chicago, IL 60612, USA Female reproductive hormones, menstrual status, and sleep Female reproductive hormones regulate the potential for, or support of, conception and pregnancy, and through their central nervous system actions, affect many functional outcomes, including sleep and thermoregula- tion. Sleep in women, therefore, may be influenced by the cyclicity of repro- ductive hormones, which have multiple periodicities, including daily and monthly, and vary according to several phases and stages. Phases and stages include becoming and being fertile (follicular, ovulatory and luteal phases), adapting to fertilization failure (menstruation), being pregnant, being post- partum and lactating, and various phases of advancing to cessation of fer- tility (climacteric and menopausal). In particular, the menstrual cycle, pregnancy, and menopausal transition form a set of contexts within which sleep has been studied in women. Cyclical and aging menstrual status changes in women create challenges to the design of studies. Interpretation of sleep patterns and detection of abnormalities across individuals is based on comparisons to ÔnormalÕ or across contexts or time. To make successful cross-sectional comparisons, standardization of physiologic status is needed. These comparisons are not easy, nor is detecting appropriate phases or stages for longitudinal studies. Because women at various chronological ages can exhibit varied biological age outcomes, multiple assessments can be needed to confirm or track the cycle phase or stage and rule out pregnancy or perhaps menopause transi- tional status. Examples of methods for standardizing the context for studies of young menstrual women, include confirming ovulation (body tempera- ture monitoring, hormone assays), assessing ovarian hormone concentra- tions, pregnancy tests, documenting parity, determining menstrual phase, and selecting women ÔonÕ or Ôoff Õ exogenous hormones. Standardizing for studies of pregnant and postpartum women includes determining weeks * E-mail address: jshaver@uic.edu (J.L.F. Shaver). 0029-6465/02/$ - see front matter Ó 2002, Elsevier Science (USA). All rights reserved. PII: S 0 0 2 9 - 6 4 6 5 ( 0 2 ) 0 0 0 3 3 - 6 Nurs Clin N Am 37 (2002) 707–718