Objective: Our objective was to characterize the endometria of women of various ages placed on similar estrogen/progesterone replacement regimens prior to attempted donor embryo transfer using histologic, ultrasonographic, and steroid receptor markers in order to determine if advancing age has a detrimental effect on uterine responsiveness to pharmacologic sex steroid replacement therapy.
Study design: This was a prospective open clinical trial. Functionally agonadal women aged 25 to 60 years receiving hormone replacement therapy underwent transvaginal ultrasound examination of the uterus followed by a timed endometrial biopsy on artificial cycle day 21. Endometrial histology and estrogen and progesterone receptors were analyzed from biopsy material. Subjects were assigned to three groups according to age: Group I, aged 25 to 39 years (n = 48); Group II, aged 40 to 49 years (n = 61); and Group III, aged 50 to 60 years (n = 13). Endometrial preparation was accomplished in all patients using the same sequential regimen consisting of oral micronized estradiol and intramuscular progesterone.
Results: Similar histologic, ultrasonographic, and steroid receptor characteristics were noted in all groups of patients regardless of age. A normal appearing midluteal secretory endometrium was demonstrated histologically in 85% of biopsies. However, 15% of biopsies exhibited intraluminal papillary excrescences within the glands and/or increase in the normal gland-to-stroma ratio. Three patients, one from each group, did not initially respond to replacement therapy and required further treatment.
Conclusion: Functionally agonadal women exhibit normal or near-normal endometrial responses to sex steroid replacement therapy designed to imitate the natural cycle through the sixth decade of life.