Transvaginal ultrasound is often recommended as a preliminary ‘non-invasive’ technique for assessing the endometrium in women with PMB. Unfortunately, it cannot give a definitive answer as to the presence or absence of malignancy, although it can sometimes be helpful in the assessment of uterine polyps. There is no consensus in the literature as to what the cut-off value for normal endometrial thickness should be. It has been reported as anywhere from 4–8 mm. Obviously the lower the cut-off value, the higher the sensitivity for detection of endometrial cancers and its precursors but at a cost of lower specificity and increased false positives.