The endometrium is the mucous membrane that lines the inside of the uterus (womb).

The endometrium changes throughout the menstrual cycle. It becomes thick and rich with blood vessels to prepare for pregnancy. If the woman does not get pregnant, part of the endometrium is shed, causing menstrual bleeding.

Current as of: February 20, 2015

Author: Healthwise Staff

Medical Review: Sarah Marshall, MD - Family Medicine & Femi Olatunbosun, MB, FRCSC - Obstetrics and Gynecology