VAGINAL ADMINISTRATION OF LOW-DOSE CONJUGATED ESTROGENS - SYSTEMIC ABSORPTION AND EFFECTS ON THE ENDOMETRIUM

Objective: To test the hypothesis that a very-low-dose regimen of vagi nal estrogen would provide effective relief from atrophic vaginitis wi thout endometrial proliferation. Methods: Twenty postmenopausal women with symptoms, signs, and cytologic evidence of atrophic vaginitis wer e enrolled. Each subject was treated with 0.3 mg of conjugated estroge ns, administered vaginally 3 nights per week for 6 months. We examined the following outcomes: symptoms, vaginal cellular (cytologic) maturi ty, endometrial histology, sonographic evaluation of endometrial thick ness, Doppler measures of uterine artery blood now, and serum levels o f estrone and estradiol. Pre- and posttreatment data were compared for each subject. Results: Satisfactory relief of symptoms occurred in 19 of 20 cases. Vaginal cellular maturation improved significantly with therapy (P<.01). There were no significant changes in endometrial thic kness, uterine artery blood flow, or serum estrogen levels. Endometria l proliferation was observed in one case. Conclusions: Relief from atr ophic vaginitis can be achieved with 0.3 mg of conjugated estrogens ad ministered vaginally three times per week. Endometrial proliferation m ay occur at this low dose, albeit rarely.