The Association of Hysterectomy and Menopause: A Prospective Cohort Study
Farquhar CM, Sadler L, Harvey SA, Stewart AW
Summary and Viewpoint
Hysterectomy is one of the most common surgical procedures performed in Western countries, with as much as one third of women in the United States reporting a history of hysterectomy by age 60. Although it has the attendant risks that are associated with any major surgical procedure, its ubiquity has made it appear fairly benign for both physician and patient alike. Indeed, hysterectomy has been associated with a number of good outcomes. In a cohort study of 418 women undergoing hysterectomy for benign conditions, hysterectomy not only improved pelvic symptoms but also self-assessed mental health, general health, and activity in patients at 1 year following the procedure.
Also noted in the above cohort study, however, was a rate of hot flashes of 13% at 1 year. This piece of data highlights a concern that hysterectomy may promote earlier menopause. Data from the National Health and Examination Survey III indicated that women who had undergone hysterectomy with unilateral oophorectomy had an adjusted odds ratio of 2.4 for a follicle-stimulating hormone (FSH) level greater than 20 compared with age-matched controls who had an intact uterus and ovaries. The odds ratio for elevated FSH was 1.5 for women who had a hysterectomy without oophorectomy. Similarly, in a prospective study of women with dysfunctional uterine bleeding undergoing either hysterectomy or endometrial ablation, the FSH values rose in both groups significantly in the 1-year follow-up after the procedure. The extent of the FSH increase was similar in the hysterectomy and endometrial ablation cohorts.
This study by Farquhar and colleagues is the first study to prospectively follow FSH levels in women undergoing hysterectomy for 5 years. An FSH level of at least 40 IU/L was used as a marker of ovarian dysfunction that could be considered truly menopausal. Women who underwent hysterectomy were likely to experience menopause an average of nearly 4 years earlier than women who did not undergo hysterectomy. In addition, women who had unilateral oophorectomy with hysterectomy experienced menopausal concentrations of FSH 4 years earlier than those women undergoing hysterectomy with preservation of both ovaries.
This study is limited by several factors. Women in the hysterectomy group were more likely to be non-European, smokers, overweight, and multiparous than women in the control group. However, multivariate analyses accounting for these factors did not significantly alter the study's main findings. Another possible study flaw was the inclusion of women receiving hysterectomy for dysfunctional uterine bleeding, a symptom that could herald the advent of menopause. To account for this possible confounding factor, the study authors recruited only women with initial FSH levels in the normal range for premenopausal women. In addition, a post hoc analysis of data based on the indication for hysterectomy did not significantly alter the study's main findings.
Earlier menopause does not only mean that symptoms of menopause will commence sooner, but it places the patient at some significant health risk as well. This is especially true now that the use of hormone therapy for chronic disease prevention in menopausal women is discouraged. Earlier menopause increases the risk for osteoporosis, and a cohort study of 12,115 postmenopausal women demonstrated that each year of delay of the beginning of menopause was associated with a 2% reduced risk for cardiovascular mortality.
Many women who present with benign indications for possible hysterectomy, including dysfunctional uterine bleeding or chronic pelvic pain, are referred to the operating room without much regard for future ovarian function. Many of these women may also have "soft" indications for surgery. Physicians should consider all of the risks, including a possible earlier menopause, that are associated with surgery and balance these risks with the possible benefits of hysterectomy for each individual patient. When the patient and the physician understand this balance, then a conscientious decision regarding surgery can be made together.
Medscape Family Medicine. 2005;7(2) © 2005 Medscape
Cite this: Viewpoint: Does Hysterectomy Promote an Earlier Menopause? - Medscape - Oct 06, 2005.