Objective: To determine whether or not hysterectomy leads to an earlier onset of the menopause.
Design: A prospective cohort study.
Setting: Gynaecology service of large urban hospital.
Population: Premenopausal women with and without hysterectomy.
Methods: Multivariate survival analysis techniques were used to adjust for differences in initial follicle stimulating hormone (FSH) levels, body mass index, smoking and unilateral oophorectomy between the groups.
Main outcome measures: FSH levels were measured for five years following hysterectomy and compared with the comparison group. Menopause was defined as a single FSH measurement of at least 40 IU/L.
Results: Two hundred and fifty-seven women undergoing hysterectomy were compared with 259 women who had not undergone a hysterectomy. Fifty-three women (20.6%) in the hysterectomy group and 19 women (7.3%) in the comparison group reached menopause over the five years of the study. Women in the hysterectomy group with a pre-operative FSH <10 IU/L reached menopause 3.7 years (95% CI 1.5-6.0 years) earlier than women in the comparison group independent of BMI, smoking and unilateral oophorectomy. Twenty-eight women in the hysterectomy group had unilateral oophorectomy and 10 (35.7%) of these women reached menopause over the five years of follow up. Women in the hysterectomy group with unilateral oophorectomy reached menopause 4.4 years (95% CI 0.6, 7.9 years) earlier than women with both ovaries in the hysterectomy group independent of baseline FSH, BMI and smoking.
Conclusions: Hysterectomy is associated with an earlier onset of menopause. Hysterectomy with unilateral oophorectomy is associated with an even earlier onset of the menopause in this study.