Endometrial evaluation with transvaginal ultrasound during hormone therapy: a prospective multicenter study.

Objective: To assess the value of endometrial thickness as a marker of endometrial abnormality risk during hormone therapy (HT) and to study the correlation between abnormal bleeding and abnormal endometrial histology in patients with thick endometrium.
Design: Prospective multicenter study.
Setting: University and general hospitals outpatient centers.
Patient(s): Postmenopausal women (702) on HT.
Intervention(s): Biendometrial thickness was measured by transvaginal sonography (TVS) between day 5 and day 10 after the last P intake and, when present, after the end of the menstrual-like bleeding.
Main Outcome Measure(s): Hysteroscopy and biopsy were performed within 5 days from TVS on all patients with an endometrial thickness 4.5 mm (precision scale 0.5 mm).
Result(s): Endometrial thickness 4.5 mm was observed in 20.5% of patients. One hundred sixteen hysteroscopies and biopsies were performed. Hyperplasia, polyps, and endocavitary fibroids were detected in 15%, 24%, and 8% of cases, respectively. The positive predictive value of TVS examination was 47%. Endometrial thickness was the only variable significantly and independently associated with histologic abnormalities and endocavitary fibroids. Abnormal bleeding occurred in 17.1% of patients. Among 17 patients detected with thick endometrium and hyperplasia, 8 cases showed abnormal bleeding.
Conclusion(s): Sonographic endometrial thickness of 4.5 mm provides a sensitive tool to select HT patients who might benefit from hysteroscopy and biopsy. Abnormal bleeding is not a sensitive sign of hyperplasia in patients with thick endometrium.