Effects of estrogen on urethral function in women with urinary incontinence.

In a prospective study, 2 gm of conjugated estrogen vaginal cream was administered daily for a total of 6 weeks in a group of 11 postmenopausal women with urodynamically proved genuine stress incontinence. Midurethral cytologic studies and a complete clinical and urodynamic evaluation were performed twice at 6-week intervals. Clinically, six of the 11 patients (54.5%) were cured or improved significantly after estrogen treatment, whereas the other five patients (45.5%) were clinically unchanged. The favorable clinical response correlated with urodynamic findings of increased urethral closure pressure and improved abdominal pressure transmission to the proximal urethra (p less than 0.05); in the patients who had a poor clinical response to estrogens, no significant changes in urethral dynamics were noted. Changes in urethral cytologic findings also correlated well with clinical and urodynamic findings. Patients with a favorable response to estrogen showed a maturation change from transitional to intermediate squamous epithelium (p less than 0.02), whereas nonresponders showed no significant changes in urethral cells.