Endometrial thickness

The endometrialEndometrial thickness is a commonly measured parameter on routine gynaecological ultrasound and MR imaging. The appearance as well as the thickness of the endometrium will depend uponon whether the patient is of reproductive age or post-menopausal and if of reproductive age, at what point in the menstrual cycle they are examined.

Radiographic assessment

Ultrasound (trans-vaginal)

The endometrium should be measured in the long-axis or sagittal plane. The measurement is of the thickest echogenic area from one basal endometrial interface across the endometrial canal to the other basal endometrium. Care should be taken not to include the hypo-echoic myometrium in this measurement.

ValuesNormal range

Commonly accepted trans-vaginal ultrasound values are as follows.

Pre menopausal

In pre menopausal patients it significantly varies according to the stage of the menstrual cycle.

• during menstruation ^1,4 : 2 - 4 mm
• early proliferative phase (day 6-14 ) : 5-7 mm
• late proliferative - pre ovulatory phase : up to 11 mm
• secretory phase : 7-16 mm
• following dilatation and curettage or spontaneous abortion : < 5 mm  : If higher be suspicious of - if it is thicker consider retained products of conception.

Post menopausal

Will depend on the use of use of hormonal therapy / Tamoxifen

• if on no medication ⁵ : < 5 mm
  • if there is vaginal bleeding, the risk of carcinoma is ~ 7% if endometrium is > 5 mm ⁸
  • if there is no bleeding, the risk of carcinoma is ~ 7% if the endometrium is > 11 mm ⁸
• if on hormonal therapy ⁶ : 8-15 mm upper limit
• if on Tamoxifen ³ :  < 6 mm (although ~ 50% of those receiving Tamoxifen have been reported to have thickness of > 8 mm ⁷)

See also

• Tamoxifen associated endometrial changes
• endometrial hyperplasia
• endometrial atrophy
• abnormally thickened endometrium