Interpreting Endometrial Thickness

Interpretation Based on Menopausal Status

In postmenopausal women, an endometrial thickness of 6.6 mm exceeds the 5 mm threshold that generally prompts endometrial tissue sampling, as it may indicate underlying pathology 1, 2
An endometrial thickness ≥5 mm in postmenopausal women has been associated with endometrial hyperplasia, polyps, or malignancy 1
The negative predictive value for cancer approaches 100% when the endometrium measures ≤4 mm in postmenopausal women, but risk increases with greater thickness 1, 2
In premenopausal women, an endometrial thickness of 6.6 mm may be entirely normal depending on the phase of the menstrual cycle 1, 2
There is no validated absolute upper limit cutoff for endometrial thickness in premenopausal women 1
Normal endometrial thickness varies throughout the menstrual cycle in premenopausal women, making the 6.6 mm measurement less concerning than in postmenopausal women 2

For postmenopausal women with an endometrial thickness of 6.6 mm, endometrial sampling is recommended as this exceeds the 5 mm threshold 1, 2
Abnormal echogenicity and texture of the endometrium correlates with underlying uterine pathology regardless of thickness 1, 2
Consider sonohysterography if focal abnormality is suspected 1

Transvaginal ultrasound should be combined with transabdominal ultrasound to fully evaluate pelvic structures 1, 2
Color and spectral Doppler should be used to evaluate internal vascularity, which can help identify vessels within endometrial polyps or cancer 1
While endometrial thickness measurement is sensitive, it cannot reliably determine the etiology of endometrial thickening 1, 2
If initial ultrasound findings are inconclusive, sonohysterography may be considered to further characterize endometrial abnormalities 2