Summary

Objectives: To assess the effect of a vaginal ring delivering estradiol and progesterone in postmenopausal women and to determine whether continuous administration can relieve climacteric symptoms, produce an acceptable pattern of vaginal bleeding and control endometrial proliferation.

Methods: Twenty-nine postmenopausal women with an intact uterus were studied. All had climacteric symptoms. The vaginal rings contained 0.36 g estradiol and either 3.6 g progesterone (high dose progesterone) or 1.8 g (low dose progesterone), and were kept in place for 4–6 months. Serum progesterone, estradiol and estrone were measured and endometrial thickness determined. All women kept a daily diary of bleeding/spotting and completed a questionnaire on climacteric symptoms at monthly intervals. The low dose progesterone group comprised 14 women and the high dose progesterone group 15 women.

Results: A total of 18 patients (9 in each group) completed the study. Mean levels of estradiol, estrone and progesterone were at their peak after 2 to 4 weeks. All rings were effective in alleviating vasomotor symptoms, although there was evidence of the "escape from effect" in month 6. Endometrial thickness increased in 6 of the 29 women but biopsy in each case showed no evidence of hyperplasia. Of the 18 women who completed the study, 5 had amenorrhea throughout, 7 had amenorrhea after 3 months, and the remainder had one or two bleeding episodes after 3 months. Therapy was discontinued in 11 women.

Conclusions: A vaginal ring delivering estradiol and progesterone controlled climacteric symptoms, prevented endometrial proliferation, and provided an acceptable bleeding pattern. It should be viewed as a promising alternative for short-term estrogen-progesterone therapy.