The available evidence shows that the use of local estrogen treatment may improve the symptoms of urinary incontinence in postmenopausal women but that systemic estrogen worsens incontinence, according to an interventional review and meta-analysis conducted by the Cochrane Incontinence Group.1
To evaluate whether local or systemic estrogen therapy has any effect on urinary incontinence, researchers identified 34 randomized or quasi-randomized controlled trials that in at least 1 arm studied local or systemic estrogen in women with stress, urgency, or mixed urinary incontinence or other urinary symptoms in postmenopausal women. These 34 trials involved 19,675 women; of these, 9599 women received estrogen therapy. Estrogen was administered vaginally to 1464 of the women who received estrogen therapy.
The researchers found that women who were administered oral systemic estrogen reported worsening incontinence than women who received placebo (risk ratio, 1.32). The researchers explained that this result was strongly influenced by a subgroup of women, all of whom had undergone a hysterectomy, from a large study that used conjugated equine estrogen and had a 1-year follow-up.2 However, the same result—a significant worsening of incontinence—was also found among women whose uterus was intact who received combined estrogen and progestogen. (risk ratio, 1.11).
When estrogen was used locally, such as via vaginal creams or pessaries, women reported a slight improvement—1 or 2 fewer voids in a 24-hour period—in symptoms related to incontinence (risk ratio, 0.74). Women who received local estrogen therapy also reported less frequency and urgency. There were some reports of vaginal spotting, breast tenderness, and nausea associated with local estrogen use, but there were no cases of serious adverse events reported in the included trials. Pelvic floor muscle training, however, may lead to a greater improvement in incontinence symptoms than local estrogen therapy (risk ratio, 2.30), reported the authors after evaluating one small trial included in the analysis.
Interestingly, the use of systemic estrogen replacement in women who are continent may actually be associated with the development of incontinence. One large study that was evaluated in this review showed that incontinence was more likely to develop in continent women who received systemic estrogen replacement with or without progestogens for a reason other than incontinence. In addition, heart disease, stroke, and breast and uterine cancer may be associated with the long-term use of systemic estrogen therapy.
- Symptoms of urinary incontinence may be improved with the use of local estrogen treatment.
- Systemic hormone replacement therapy with conjugated equine estrogen may worsen urinary incontinence.