Are vaginal estrogens effective for preventing urinary tract infection in postmenopausal women?

Urinary tract infection commonly affects postmenopausal women, probably because of the changes in vaginal flora secondary to estrogen deficiency. So, the use of vaginal estrogens could revert this process and then decrease the risk of infection. However, it is not clear whether they are really effective.

To answer this question we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach.

We identified seven systematic reviews including four primary studies overall and all were randomized trials. We concluded it is not clear whether vaginal estrogens decrease the risk of symptomatic urinary infection because the certainty of the available evidence is very low.