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Scientific Definitions for Menopause Related Terminology

Established By The International Group

Throughout the world, misuse of terminology related to the field of menopause has caused a great deal of confusion and misinformation among healthcare providers, those in research, the media, and the public. To help ensure a standardized definition of key words used in the field, the International Menopause Society (IMS) commissioned a project through its international policy organ the Council of Affiliated Menopause Societies (CAMS).

Because terms such as premature menopause and perimenopause have not had specific scientific definitions, their use has caused confusion among those in the menopause field. In fact, even the definition of menopause itself is not the same around the world.

The following list of menopause-related definitions was approved by the Board of the IMS on October 11, 1999, in Yokohama, Japan. Wherever possible, current accepted definitions in the medical literature were left intact to avoid adding confusion to this area.

The IMS and CAMS organizations - including the North American Menopause Society - urge all those involved in menopause health care and research to adopt these refined definitions. Only through proper communication can we work together toward improving the health of women as they reach menopause and beyond.

CAMS Menopause-Related Definitions

Term Source
Menopause (natural menopause). The term natural menopause is defined as the permanent cessation of menstruation resulting from the loss of ovarian follicular activity.

Natural menopause is recognized to have occurred after 12 consecutive months of amenorrhea, for which there is no other obvious pathological or physiological cause. Menopause occurs with the final menstrual period (FMP) which is known with certainty only in retrospect a year or more after the event. An adequate biological marker for the event does not exist.

Perimenopause. The term perimenopause should include the period immediate prior to the menopause (when the endocrinological, biological, and clinical features of approaching menopause commence) and the first year after menopause. WHO
Menopausal transition. The term menopausal transition should be reserved for that period of time before the FMP when variability in the menstrual cycle is usually increased. This term can be used synonymously with "premenopause," although this latter term can be confusing and preferably should be abandoned. WHO
Climacteric. The phase in the ageing of women marking the transition from the reproductive phase to the non-reproductive state. This phase incorporated the perimenopause by extending for a longer variable period before and after the perimenopause. IMS
Climacteric Syndrome. The climacteric is sometimes, but not necessarily always, associated with symptomatology. When this occurs, it may be termed the "climacteric syndrome". IMS
Premenopause. The term premenopause is often used ambiguously to refer to the one or two years immediately before the menopause or to refer to the whole of the reproductive period prior to the menopause. The group recommended that the term be used consistently in the latter sense to encompass the entire reproductive period up to the FMP. WHO
Postmenopause. The term is defined as dating from the FMP, regardless of whether the menopause was induced or spontaneous. WHO
Premature Menopause. Ideally, premature menopause should be defined as menopause that occurs at an age less that two standard deviations below the mean estimated for the reference population. In practice, in the absence of reliable estimates of the distribution on age at natural menopause in populations in developing countries, the age of 40 years is frequently used as an arbitrary cut-off point, below which menopause is said to be premature. WHO
Induced Menopause. The term induced menopause is defined as the cessation of Menstruation which follows either surgical removal of both ovaries (with or without hysterectomy) or iatrogenic ablation of ovarian function (eg by chemotherapy or radiation). WHO


  1. Utain WH and Serr D. The Climacteric Syndrome. In: Consensus on Menopause Research. Van Keep PA, Greenblatt Royal Brisbane Hospital and Albeavx-Fernet M (eds), MTP Press, Lancaster, 1976 pp. 1-4.
  2. Utian WH. Ovarian function-therapy oriented definition of menopause and climacteric. Experimental Gerantol 29, 245-251, 1994.
  3. WHO Scientific Group on Research on the Menopause in the 1990's. WHO Technical Report Series 866, Geneva, Switzerland, 1994.

Last Updated August 2008

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