Background: The purpose of this study was to compare the effects of hysterectomy and a levonorgestrel-releasing intrauterine system (LNG-IUS) on serum FSH levels and menopausal symptoms.
Methods: A total of 236 women referred for menorrhagia to five university hospitals were randomly assigned to treatment with hysterectomy (n = 117) or LNG-IUS (n = 119). Menopausal symptoms were characterized by the Kupperman menopausal distress test. Serum FSH and estradiol levels were measured at baseline and 6 and 12 months after hysterectomy or application of LNG-IUS. Analyses were by intention to treat.
Results: After 6 months, there was no difference between the groups, but 12 months after follow-up hysterectomized women had higher FSH levels than women with LNG-IUS (P = 0.005). There was a significant association between FSH levels and treatment modality (P = 0.020). Hot flushes increased significantly in the hysterectomy group (P = 0.02). There was a significant association between hot flushes and both treatment modality and age (P = 0.02 and P = 0.01, respectively).
Conclusion: Hysterectomy may impair ovarian function shown by rising serum FSH levels and hot flushes. However, these results should be interpreted with caution, and longer follow-up is needed.