Hormone replacement therapy aggravates postmenopausal urinary incontinence.

(1) In the WHI trials, which involved more than 20 000 women, the frequency of urinary incontinence increased among postmenopausal women taking hormone replacement therapy compared with placebo. Among women who were continent at enrollment, the frequency of stress incontinence at 1 year was 16% with an oestrogen-progestin combination, compared with 9% with placebo (relative risk 1.87, 95% confidence interval: 1.61-2.18). Among women who were already incontinent, the relative risk of aggravation with hormone replacement therapy compared with placebo was about 1.40. (2) The results of another trial involving nearly 3000 women were similar. (3) Other, smaller trials failed to show any positive impact of oestrogen-progestin therapy on urinary incontinence in postmenopausal women. (4) In practice, postmenopausal hormone replacement therapy does not protect against urinary incontinence; on the contrary, it may trigger or worsen urinary incontinence.