Background: Abnormal uterine bleeding (AUB) is a common and serious problem in women of late reproductive age and an indication for endometrial biopsy as an invasive method. On assessing AUB, in some cases, even with the observation of normal thicker endometrium in ultrasonography, abnormal biopsy is reported. Thus, this study was carried out to assess the role of measuring endometrial thickness by transvaginal ultrasonography as a screening tool for premenopausal women with abnormal uterine bleeding.

Materials and Methods: In this diagnostic study, 154 premenopausal women with AUB referred to Naghavi Clinic of Kashan university of medical sciences during 2010-11. Transvaginal ultrasonography was performed to assess endometrial thickness before the Pipelle endometrial biopsy at the first day of menstruation. The biopsies were then sent to a pathologist unaware of the results of transvaginal ultrasonography and finally, the Roc curve was utilized to determine the best cut-point.

Results: Forty-eight out of 154 cases (31.2%) had abnormal endometrium (hyperplasia 23.2% polyps 3.9% and asynchronous 3.9%). The reported thickness of endometrium with the sensitivity and specificity of 76.2% and 41.1% (PPV=33.6%, NPV=82.1%, LR+=1.29 and LR-=0.58) was 7 mm.

Conclusion: Although endometrial thickness of ≤7mm in premenopausal women with abnormal uterine bleeding is less likely to be associated with malignant pathologies, assessing the endometrial thickness merely with transvaginal ultrasonography is not merely suggested for the diagnosis of endometrial abnormalities.