Ask The Doctor: Birth Control... Health Article

Joan Bengtson, M.D., is assistant professor of obstetrics, gynecology and reproductive biology at Harvard Medical School and a member of the Department of Obstetrics, Gynecology & Reproduction at Brigham and Women's Hospital.

Question:

I take birth control pills (Yasmin). My gynecologist said that if I continue using them, my menopause transition would be much easier. But I am concerned about the risk of breast cancer. Does the pill contain the same medication as Prempro, the hormone-replacement drug that has been linked to breast cancer?

Answer:

Yes, birth control pills and Prempro both contain an estrogen and a progesterone hormone. However, the dose is much higher in the pill than in Prempro. The higher dose is needed for the pill to prevent pregnancy. The lower dose in Prempro is designed to replace hormone levels normally secreted by the ovaries.

The Women's Health Initiative showed that women who used estrogen/progesterone hormones for more than four years after menopause had a higher risk of breast cancer. Short-term use did not pose a significant increase in the risk. Because menopausal symptoms usually go away in one to two years, most women can consider using hormones, if necessary, to control hot flashes, irregular bleeding and sleep disturbances.

Many studies have examined the relationship of birth control pill use by premenopausal women with their subsequent risk of breast cancer. Most studies show no increased risk, even with long-term use. The reasons for the differences in risk are not completely understood. The age of the patient, menopausal status, and hormone dose are some factors that might influence the risk.

References:

Hankinson SE et al. Cancer Causes Control 1997 8(1): 65-72.

Chlebowski RT, et al. JAMA 2003; 289(24): 3243-53.