Association of endometrial thickness with lesions in postmenopausal asymptomatic women: risk factors and diagnostic thresholds.

Purpose: This study aimed to explore the relationship between endometrial thickness and lesions in asymptomatic postmenopausal women and identify diagnostic thresholds for lesions.

Methods: A total of 279 postmenopausal asymptomatic women aged 40 years or older with endometrial thickness ≥ 4 mm were retrospectively selected in our hospital, from January 2018 to June 2023, there were 33 cases's operations which were failed due to the cervical stenosis, 8cases who used hormone replacement therapy within the past year, 7 cases with hysteromyoma that affect the shape of the uterine cavity line, and 5cases's hysteroscopic tissue acquisition were failed. Finally, A retrospective study was conducted on the endometrial thickness of 226 postmenopausal asymptomatic women measured by transvaginal ultrasound and those with thickening were subjected to hysteroscopy and pathological examination of endometrial biopsy tissues, and were divided into a normal group (80 cases), benign lesion group (143 cases), and malignant lesion group (3 cases) according to the pathology results. The endometrial thickness results measured by vaginal ultrasound were compared with the endometrial histopathologic results.

Results: 1. There were 226 cases in all, including 117 cases of endometrial polyps (51.7%);2. BMI ≥ 25 kg/m² is a risk factor to postmenopausal asymptomatic women. OR = 1.132 P < 0.05,95%CI (1.039,1.234);3. endometrial thickness ≥ 4 mm is a risk factor to postmenopausal asymptomatic women. OR = 7.927 P < 0.05, 95%CI (3.015,20.839);4. The results of the Receiver Operating Characteristic (ROC) analysis of the subjects show that the optimal cut-off value for screening endometrial pathology by endometrial thickness in asymptomatic postmenopausal women is 5.65 mm, and its area under the curve for identifying endometrial lesion was 0.679.

Conclusion: 1. The main cause of endometrial thickening after menopause was endometrial polyps (51.7%). 2. Overweight (BMI ≥ 25 kg/m²) is a risk factor for asymptomatic endometrial thickening after menopause. 3. endometrial thickness ≥ 4 mm is a risk factor to postmenopausal asymptomatic women. 4. The appropriate diagnostic threshold of vaginal ultrasound diagnosis is 5.65 mm in asymptomatic postmenopausal women.