Influence of hormone replacement therapy on postmenopausal pelvic organs.

Objective: To assess the influence of hormone replacement therapy (HRT) on the pelvic organs of postmenopausal women by vaginal ultrasonography.

Design: The study (case-control) included 753 consecutive, postmenopausal women who were referred for routine transvaginal ultrasound examination. A total of 290 women who were using HRT at the time of examination (study group) were compared with 463 who were not treated (control group).

Results: The women using HRT were younger and had been menopausal for a shorter period, compared with those who had not been treated. Mean uterine volume, endometrial thickness and ovarian area were all increased in the HRT group, compared to the control group. A negative correlation was found between menopausal age and uterine volume, and ovarian area in both treated and untreated groups. However, endometrial thickness was negatively correlated with menopausal age in the untreated group only. After controlling for various parameters, a multivariate logistic analysis demonstrated that endometrial thickness was treatment status-dependent only. Uterine volume was also treatment status-dependent, but was also negatively correlated with menopausal age. As expected, the endometrium was thicker and the uterine volume was larger in the treated group. Ovarian area was not found to be treatment-dependent for all menopausal ages.

Conclusions: Postmenopausal women treated with HRT have a larger uterus and thicker endometrium than those of non-treated matched controls. There is a negative correlation between menopausal age and uterine and ovarian size. Endometrial thickness was found to be negatively correlated with menopausal age in only the untreated group, and is almost entirely HRT-dependent. In contrast to the uterus and the endometrium, the ovaries are not influenced by HRT.