Hysterectomy is the most common gynecological operation performed in the US. There are various types of hysterectomy which may be carried out for various reasons. Of the 600,000 hysterectomies performed yearly, about half of them are accompanied by removal of both ovaries (bilateral oophorectomy).

The justification for this is that it prevents the development of ovarian cancer which has poor survival rates mainly due to late detection and poor response to anti-cancer chemotherapy.

If a hysterectomy is done for non-cancerous conditions, the rationale for this decision becomes somewhat questionable. This is especially when one considers that there are 16,000 deaths yearly in women in the US due to ovarian cancer, 28,000 due to colon cancer, 40,000 and 48,000 for breast cancer and hip fracures respectively and 490,000 from heart disease.

Ovarian cancer is relatively uncommon in the absence of high risk factors such as a family history of this family in close relatives.

The ovaries are important in all stages of a woman's life. Before menopause, they produce estrogen, progesterone and the androgens (male sex hormones) testosterone and androstenedione. After menopause, they continue to produce androgens. These androgens are converted to estrone (a less potent estrogen than estradiol) in the fat cells, skin and muscle cells. Thus, while progesterone levels fall drastically at menopause, estrogen levels may be up to 40% of their premenopausal levels for several years.

The reduced levels of estrogen still have some protective effects on the heart and bones which are maintained up to the age of 75 years (though decreasing gradually over time).

Women who have their ovaries removed after the age of 50 have a 40% greater chance of having a myocardial infarction (heart attack) compared to women whose ovaries are intact.

Estrogens and androgens slow down the rate at which the bones are re-absorbed while androgens in particular, increase bone formation. This helps to slow down the development of osteoporosis. Post-menopausal women who have had oophorectomies are 50% more likely to have osteoporotic fractures.

The health implications are even greater for pre-menopausal women who have "protective" oophorectomies which may result in the gradual or sudden onset of menopausal symptoms. Apart from the reduction in their quality of life, they are put at greater risk of developing heart disease, osteoporosis and strokes.

The conventional response to this has been to offer hormone replacement therapy (HRT) in the form of combined estrogen/progesterone supplements, the most popular being Prempro.

However, following results of studies carried out under the Women's Health Initiative (WHI) on various aspects of menopausal health, only about 17% of women have elected to keep taking conventional HRT. Women have also been very reluctant to start HRT with the onset of menopausal symptoms.

In addition, of women who start taking bisphosphonates and statins as non-hormonal alternatives to prevent osteoporosis and heart disease, less than 20% are still using them after one year.

Thus, medical therapies cannot be substituted for th body's natural defences against menopause-related conditions.

If you are considering having a hysterectomy, you must weigh the potential risks and benefits of having a preventive oophorectomy against your own personal and family history and risk factors. You should work closely with your doctors to make the decision (for or against ovarian conservation) that is right for you.

The old 'one cap fits all' mentality and guidelines regarding preventive oophorectomy must be revised to tailor decisions to the individual needs of each woman.