Does Hysterectomy Cause Early Menopause?

Abstract & Commentary

By Frank W. Ling, MD, Clinical Professor, Dept. of Obstetrics and Gynecology, Vanderbilt University School of Medicine, Nashville, is Associate Editor for OB/GYN Clinical Alert.

Synopsis: Hysterectomy is associated with an earlier onset of menopause while hysterectomy with unilateral oophorectomy may be associated with an even earlier onset of menopause.

Source: Farquhar CM, et al. The association of hysterectomy and menopause: a prospective cohort study. BJOG. 2005;112:956-962.

In this New Zealand investigation, 257 premenopausal women undergoing hysterectomy were prospectively compared to 259 cohorts who did not have a hysterectomy. Over the 5 years of the study, 53 (20.6%) of the hysterectomy group experienced menopause as defined by a follicle stimulating hormone (FSH) level of > 40 IU/L compared to 19 (7.3%) of the controls. Women in the hysterectomy group with a baseline level of FSH < 10 IU/L underwent menopause 3.7 years earlier than the comparison group.

Within the hysterectomy group, 28 had a unilateral oophorectomy. These women experienced menopause 4.4 years earlier than women who retained both ovaries at the time of hysterectomy. These findings were independent of baseline FSH, smoking status, and body mass index.

Commentary

We all know that the average age of menopause is approximately 50-51. It's part of our counseling as we advise patients about incidental oophorectomy at the time of hysterectomy. How we counsel patients about the effect of hysterectomy on menopause may be something that we need to pay more attention to because of data such as that presented from this large, prospective study. In the past, studies have certainly suggested that hysterectomy is associated with earlier menopause, but these investigators seem to have further defined the extent.

This study is telling us that not only does menopause come earlier in women undergoing hysterectomy, but unilateral oophorectomy does make a difference also—approximately 4 years. The impact on our practice should not be enormous, but the implications should be discussed with patients, particularly since menopause does carry its own health risks and lifestyle issues. Admittedly, the patient and physician should not base the decision on whether a hysterectomy is performed or not on whether the menopause comes sooner or not. The hysterectomy should still have the appropriate indications, but since most cases are elective, ie, for quality-of-life rather than life-or-death reasons, potentially earlier menopause should at least be mentioned in the pre-operative counseling.

The authors provide no explanation for this phenomenon, so we are left with trying to answer the “Why?” on our own. We can certainly surmise that blood flow is compromised or that the pathology that required the surgery would have brought on an earlier menopause anyway. Most important is the recognition by the gynecologist that the removal of the uterus does, indeed, have effects that reach beyond the uterus itself. Unilateral oophorectomy at the time of hysterectomy should similarly be well thought out and performed recognizing the implications for the function of the remaining ovary.

Yes, a little knowledge can be a dangerous thing, but in this case, this little bit of knowledge can help us better inform and serve our patients who are considering hysterectomy. Will the possibility of an earlier menopause possibly dissuade a woman from undergoing hysterectomy? Maybe, but if that is the compelling reason to put off the surgery, you've got to ask how “necessary” the hysterectomy was in the first place. I liked the article because it made me think about how I counsel my own patients about both hysterectomy and oophorectomy.