Effects of trimonthly progestin administration on the endometrium in elderly postmenopausal women who receive hormone replacement therapy: a pilot study.

Abstract

The purpose of this study was to determine the effect of trimonthly progestin administration on the endometrium in elderly postmenopausal women who receive hormone replacement therapy. This was a prospective, randomized, double-blind, placebo-controlled study at a university teaching program. Twenty-five postmenopausal women who were >or=75 years old with an intact uterus were assigned randomly to receive conjugated equine estrogens (0.625 mg/d plus medroxyprogesterone acetate 5 mg/d for 13 days every 3 months (n = 13) or placebo (n = 12) for 9 months). At the end of the 9 months, patients in the hormone replacement therapy arm continued therapy for an additional 9 months. Statistical analysis was performed with the Student t test, the chi(2) test, and the Fisher exact test. Transvaginal sonography was performed at baseline and at 9 and 18 months. Endometrial biopsy was performed if the endometrial thickness was >4 mm or as clinically indicated at 18 months. Patients in the hormone replacement therapy group demonstrated a significant increase in endometrial thickness between baseline (3.9 + 0.8 mm) and 9 months (8.0 + 4.8 mm). There were no cases of endometrial hyperplasia at the 18-month endometrial biopsy. Trimonthly progestin administration in elderly postmenopausal women who receive hormone replacement therapy may be a reasonable alternative to the monthly administration of progestin in hormone replacement therapy.