A woman is born with four million eggs. Each month, one egg ripens and passes into the uterus and about 10,000 eggs deteriorate. When she runs out of functioning eggs, she is in the menopause.

The average woman in North America goes into menopause at age 52, but she can run out of eggs at any age. A women can go into menopause at birth or any year after that. Smoking, low educational attainment, being separated/widowed/divorced, being out-of-work, or having a history of heart disease are associated with early menopause; while having a lot of kids, having taken oral contraceptives, or Japanese race/ethnicity are associated with later age at menopause.

All women will develop osteoporosis if they live long enough, and they lose the most bone for the first three years of menopause, a woman should get a blood test called FSH when her periods become irregular. When her FSH starts to rise, she in the menopause and should get a bone density test to determine if she already has weak bones. If she does, she should start estrogen or bone strengtheners.

Factors associated with age at natural menopause in a multiethnic sample of midlife women. American Journal of Epidemiology, 2001, Vol 153, Iss 9, pp 865-874. EB Gold, J Bromberger, S Crawford, S Samuels, GA Greendale, SD Harlow, J Skurnick. Address Gold EB, Univ Calif Davis, Dept Epidemiol & Prevent Med, TB168, 1 Shields Ave, Davis,CA 95616 USA

Checked 4/9/13

Get our newsletter