The association of hysterectomy and menopause: a prospective cohort study

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.