The effect of hysterectomy or levonorgestrel-releasing intrauterine system on premenstrual symptoms in women treated for menorrhagia: secondary analysis of a randomized controlled trial.

Objective: To study the effect of hysterectomy or levonorgestrel-releasing intrauterine system (LNG-IUS) on premenstrual symptoms in women treated for menorrhagia.

Design: Secondary analysis of a randomized controlled trial.

Setting: Five university hospitals in Finland.

Sample: A cohort of 236 women, aged 35-49 years (mean 43 years) referred for menorrhagia between 1994 and 1997. Women were not diagnosed with premenstrual syndrome.

Methods: Women were randomized to treatment by hysterectomy (n=117) or LNG-IUS (n=119). Analyses were performed using the intention-to-treat and actual treatment principles. Women using estrogen therapy and women who underwent bilateral salpingo-oophorectomy were excluded from the analyses.

Main Outcome Measures: The occurrence of premenstrual symptoms evaluated by questionnaires at baseline and at follow-up visits six and 12 months after the treatment and five years after the randomization.

Results: Premenstrual symptoms decreased significantly in both groups by six months (p≤0.028) without significant differences between the groups, except that in the LNG-IUS group the decrease of breast tenderness was seen first by 12 months (p=0.048). Even though 42% of the women assigned to treatment with LNG-IUS were hysterectomized during the follow-up period, the results of intention-to-treat and actual treatment analyses were comparable.

Conclusions: Both hysterectomy and LNG-IUS seem to alleviate premenstrual symptoms of women treated for menorrhagia, while the effect of these treatments on premenstrual syndrome remains unsettled.