Purpose: To define the median endometrial thickness (ET) in office gynecology is thought to be important for clinical practice. However, there are few reports about ET that have included the general female population on a large scale. The median ET was determined prospectively in premenopausal women who attended office gynecology for cervical cancer screening.
Methods: In total, 849 women were enrolled. The median ET was determined by using transvaginal ultrasound and the relationships between the ET and various clinical factors were analyzed.
Results: The participants' median age was 38.5 years. The median ET was 8.6 mm (90% and 95% quantiles: 13.8 and 15.8 mm). The ET was not related to their age, symptoms, obstetric history, geographical location, or risk factors for endometrial cancer. In the women with a menstrual cycle length of 28-30 days, the ET was 7 mm on days 1-6, but it increased from 5.4 mm immediately after menstruation (day 7 or 8) to 9.2 mm on days 13-14. Subsequently, the ET increased further to 11.1 mm on day 18.
Conclusion: In all the women, the upper limit of the ET was 13.8 mm and 15.8 mm in the 90% and 95% quantile, respectively, in office gynecology.
Keywords: endometrial thickness; menstruation cycle; office gynecology; premenopausal women; transvaginal sonography.