Estrogen Supplementation in the Treatment of Urinary Incontinence
Source: Fantl JA, et al. Obstet Gynecol 1996;88:745-749.
For many years the use of estrogens—either systematic or topical—has been a commonly prescribed treatment to help correct and/or prevent urinary incontinence, despite little evidence of its efficacy. Because estrogen receptors have been shown to be present in the urethra, bladder, and pelvic floor musculature, it has been assumed that the use of estrogen in postmenopausal women might help to increase pelvic floor tone and thus decrease urinary incontinence.
In this study, 83 hypoestrogenic females were recruited to participate in a prospective, randomized, double-blind, placebo-controlled trial. All women were documented to have urinary incontinence. Each underwent urodynamic evaluation, maintained a micturition calendar, completed several different health surveys, and were asked to provide their subjective perception of improvement, if any. Appropriate exclusions were made. The statistical analyses were straightforward and simple.
After three months of oral estrogen or placebo, there was no difference between the groups with regard to episodes of incontinence, amount of loss, number of voids per day, or quality of life. Fifty-four percent of the estrogen-treated and 45% of the placebo-treated groups had a perception of improvement. Estradiol levels were appropriately increased in the treated women, but remained the same in the control group. A power analysis provided by the authors suggests that the study’s negative outcome is believable.
Comment by Kenneth L. Noller, MDThis is a straightforward study designed to determine whether oral estrogen therapy decreases urinary incontinence in postmenopausal women. The authors were unable to detect any improvement in any measurement. This is an important finding because estrogens are widely touted by clinicians to "tone up" the pelvic floor and thus reduce involuntary loss of urine. This study puts that myth to rest.
A number of questions do remain unanswered. For example, if a woman is started on estrogen at the time of menopause and continued on it, is she less likely to develop incontinence? The subjects of this study were all incontinent before the study began. Perhaps estrogen would work to prevent incontinence (but clearly does not work to treat it). Likewise, it is possible that estrogens promote faster healing in women who have undergone vaginal surgery, though this has not been tested in a rigorous manner.
Several years ago, I participated in an ACOG task force that reviewed and critiqued the drafts and final version of the AHCPR document on urinary incontinence. The committee that was tasked with writing the report by the federal government first reviewed the world’s literature on urinary incontinence. One of their conclusions was that there was little or no evidence that estrogens prevented or improved involuntary loss of urine. This came as a shock to many gynecologists who had been using such therapy for decades. This article appears to uphold the AHCPR conclusion.
Dr. Noller is Professor and Chairman, Department of OB/GYN, University of Massachusetts Medical Center, Worcester.