Urinary tract infections (UTI’s) are common in sexually active women of all ages, but they’re often more frequent in midlife post-menopausal women because of physiologic changes in the genitals and urinary tract associated with the loss of estrogen. This condition, called genitourinary syndrome of menopause (GSM), can cause symptoms that include pain with sex, vaginal dryness and irritation, and recurrent UTI’s. With the loss of estrogen at menopause, the vaginal pH changes. In premenopausal women with normal estrogen levels, the vagina is acidic with a pH of around 4-4.5, and is colonized with healthy lactobacilli ("friendly" bacteria). After menopause, the loss of estrogen results in an increase in vaginal pH to 5.5-6. Lactobacilli can’t survive in this more alkaline environment; instead, unhealthy bacteria take over. This change, along with thinning of the vulvovaginal tissue, [and prominence of the urethra and other physiologic changes can result in more frequent UTI’s.
Local vaginal estrogen therapy can be an effective way to prevent recurrent infections in women especially prone to them.