Women may expect to spend more than a third of their lives after menopause. Beginning in the sixth decade, many chronic diseases will begin to emerge, which will affect both the quality and quantity of a woman's life. Thus, the onset of menopause heralds an opportunity for prevention strategies to improve the quality of life and enhance longevity. Obesity, metabolic syndrome and diabetes, cardiovascular disease, osteoporosis and osteoarthritis, cognitive decline, dementia and depression, and cancer are the major diseases of concern. Prevention strategies at menopause have to begin with screening and careful assessment for risk factors, which should also include molecular and genetic diagnostics, as these become available. Identification of certain risks will then allow directed therapy. Evidence-based prevention for the diseases noted above include lifestyle management, cessation of smoking, curtailing excessive alcohol consumption, a healthy diet and moderate exercise, as well as mentally stimulating activities. Although the most recent publications from the follow-up studies of the Women's Health Initiative do not recommend menopause hormonal therapy as a prevention strategy, these conclusions may not be fully valid for midlife women, on the basis of the existing data. For healthy women aged 50–59 years, estrogen therapy decreases coronary heart disease and all-cause mortality; this interpretation is entirely consistent with results from other randomized, controlled trials and observational studies. Thus. as part of a comprehensive strategy to prevent chronic disease after menopause, menopausal hormone therapy, particularly estrogen therapy may be considered as part of the armamentarium.

An increasing number of options are available for women who wish to preserve their fertility, particularly before cancer treatment: oophorectomy with cryopreservation, embryo cryopreservation, and aspiration of oocytes for cryopreservation immediately or after ovarian hyperstimulation. This article also describes the natural process of oocyte loss and methods of testing for decreased ovarian reserve.

The polycystic ovary syndrome (PCOS) is an extremely common disorder that occurs in 4% to 7% of women of reproductive age. Although PCOS is known to be associated with reproductive morbidity and increased risk for endometrial cancer, diagnosis is especially important because PCOS is now thought to increase metabolic and cardiovascular risks. These risks are strongly linked to insulin resistance and are compounded by the common occurrence of obesity, although insulin resistance and its associated risks are also present in nonobese women with PCOS. Women with PCOS are at increased risk for impaired glucose tolerance, type 2 diabetes mellitus, and hypertension. Cardiovascular disease is believed to be more prevalent in women with PCOS, and it has been estimated that such women also have a significantly increased risk for myocardial infarction. Many lipid abnormalities (most notably low high-density lipoprotein cholesterol levels and elevated triglyceride levels) and impaired fibrinolysis are seen in women with PCOS. Early diagnosis of the syndrome and close long-term follow-up and screening for diabetes and cardiovascular disease are warranted. An opportunity exists for preventive therapy, which should improve the reproductive, metabolic, and cardiovascular risks.