When vaginal estrogen was provided to hypoestrogenic women to avoid recurrent urinary tract infections, the frequency of UTIs fell by more than 50% over the following year supporting the fact that vaginal estrogen is effective in reducing urinary tract infections.
The study results were presented at the 2022 scientific meeting of the American Urogynecologic Society and the International Urogynecological Association, Austin, TX, and published in the American Journal of Obstetrics & Gynecology on May 11, 2023.

Urinary tract infections (UTIs) are substantial health problems among females and a considerable burden to the healthcare facility. Many women suffer from breakthrough infections despite being on antibiotics. Presently vaginal estrogen is considered the standard of care to prevent recurrent UTIs among women with hypoestrogenism to avoid multidrug resistance due to antibiotics. As there are only smaller trials that studied the efficacy of vaginal estrogen in hypoestrogenic women, researchers from Kaiser Permanente, San Diego, California conducted a study to assess the association between vaginal estrogen prescription and the frequency of urinary tract infections over the following year in a diverse population of women with hypoestrogenism.
A multicenter retrospective review was carried out by including women who were prescribed vaginal estrogen for the indication of recurrent urinary tract infection from January 2009 through December 2019. Patients were asked to fill their prescriptions and continue care within Kaiser Permanente Southern California system for at least one year. Exclusion criteria included anatomic abnormalities, malignancy, or mesh erosion of the genitourinary tract.

Recurrent urinary tract infection was defined as having ≥3 positive urine cultures (separated by at least 14 days) in the 12 months preceding the index vaginal estrogen prescription.
Adherence was captured through refill data after the index prescription. Low adherence was defined as no refills; moderate adherence was defined as one refill; high adherence was defined as ≥2 refills.
Data were abstracted from the electronic medical record system using the pharmacy database and diagnosis codes. Pre- and post-prescription urinary tract infections over the year preceding and following the vaginal estrogen prescription were compared using paired t-tests. Predictors of post-prescription urinary tract infection were evaluated by multivariate negative binomial regression.
What did the study Find?
Cohort details are as follows:
No. of participants (n) 5638 women
Mean (±standard deviation) age
70.4 (±11.9) years
body mass index
28.5 (±6.3) kg/m2
baseline urinary tract infection frequency
3.9 (±1.3)
Race
White (59.9%) or Hispanic (29.7%)
postmenopausal
93.4%
The mean urinary tract infection frequency was reduced by 51.9% after the index prescription (from 3.9 to 1.8).
During the index prescription, 55.3% of patients experienced ≤1 UTIs and 31.4% experienced none.
Significant predictors of the post-prescription urinary tract infection included age (75 to 84 years), increased baseline urinary tract infection frequency, urinary incontinence, urinary retention, diabetes mellitus, and moderate or high medication adherence.
Patients with high medication adherence demonstrated more frequent post-prescription urinary tract infections than patients with low adherence.
The present study has reiterated the fact that vaginal estrogen is effective in reducing UTIs in hypoestrogenic women,
Further reading: Efficacy of vaginal estrogen for recurrent urinary tract infection prevention in hypoestrogenic women. https://doi.org/10.1016/j.ajog.2023.05.002