Endometrial thickness in premenopausal women varies with their menstrual cycle and between women. There is no cut off for normal endometrial thickness, but average thickness varies from four to fourteen millimeters during different parts of the cycle. The lining is thinnest four to six days after menstruation begins, and thickest immediately prior to menstruation. If you have normal menses without heavy or unusual bleeding
, your uterine lining is likely normal.
Endometrial thickness is much more important in older, postmenopausal women who are having abnormal bleeding. For those women, thick endometrium can be an important sign of endometrial cancer, and will often result in a biopsy
. However, the lining thickness is not as helpful in premenopausal women, even if they have abnormal bleeding.
If you have concerns about your reproductive system, it is very important to schedule an appointment with your physician. He or she will be able to assess your other medical conditions, history, and current physical exam to determine if further evaluation is warranted.