Is 5mm endometrial thickness normal?

The endometrium is an important component of the uterus and is very important for women because it can ensure the health of their reproductive system and fertility. If there is a disease in the endometrium, it will also cause great pain to women. The endometrium has a certain thickness, and the thickness of the endometrium varies at different stages. Next, I will introduce to you the normal thickness of the endometrium.

The thickness of the endometrium is related to the cyclical changes of the endometrium. The cyclical changes of the endometrium include histological changes and biochemical changes of the endometrium. The normal thickness of the endometrium and the histological changes of the endometrium are affected. How thick is the normal endometrium? The normal thickness of the endometrium can be 1-10mm depending on the cycle. The functional layer of the endometrium is the site where the embryo implants. It is regulated by changes in ovarian hormones and has periodic proliferation, secretion, and shedding changes. The specific histological changes divide the menstrual cycle into three stages: proliferation, secretion, and menstruation (taking a normal menstrual cycle of 28 days as an example):

1. Proliferation stage

Day 5-14 of the menstrual cycle. During this period, the thickness of the endometrium increases from 0.5mm to 3-5mm. The proliferation period is divided into early proliferation period, middle proliferation period and late proliferation period. In the early proliferation stage, which is 5-7 days in the menstrual cycle, the endometrium is relatively thin, only 1-2mm. The mid-proliferative phase is the 8th to 10th day of the menstrual cycle, when the endometrial glands increase in number and size. By the 11th to 14th day of the menstrual cycle, it has entered the late proliferation stage, and the endometrium further thickens to 3-5mm.

2. Secretory phase

Day 15-28 of the menstrual cycle. The endometrium increases from 5mm to 10mm. This phase corresponds to the luteal phase of the ovarian cycle. The secretory phase is divided into early secretory phase, middle secretory phase and late secretory phase. The early secretory period is from the 15th to the 19th day of the menstrual cycle, during which the endometrial glands are longer and more curved. The mid-secretory phase is from the 20th to the 23rd day of the menstrual cycle, and the endometrium is thicker than before and has a serrated shape. On the 24th to 28th day of the menstrual cycle, this period is the pre-menstrual period, which is equivalent to the luteal phase regression stage. The endometrium at this stage is spongy and up to 10 mm thick.

3. Menstrual period

Days 1-4 of the menstrual cycle. This is the period when the spongy functional layer of the endometrium disintegrates and falls off from the basal layer, which is the final result of the withdrawal of progesterone and estrogen.