Estrogen effects on the urethra: beneficial effects in women with genuine stress incontinence.

The urethra, which originates from the urogenital sinus, is under the influence of estrogen just like the vagina. The concentration of estrogen receptors in the urethral mucosa is similar to that of the vaginal mucosa. Estrogen deprivation will result in atrophic urethritis and sometimes urinary incontinence, and estrogen replacement therapy may reverse this trend. Estrogens have been shown to increase urethral pressure in up to 30 per cent of women and to significantly improve or cure stress urinary incontinence in many cases. Adding alpha-sympathomimetic drugs to estrogens may further improve symptoms in women with stress incontinence. It seems that vaginal estrogens have more beneficial effect on the urethra, compared with the oral medication, although prospective control studies have not always supported these findings. Overall, it seems that estrogens have beneficial effects on urethral function in women with postmenopausal stress incontinence, although more prospective randomized control studies are needed to assess the effect of estrogens on the lower urinary tract.