Definition - What does Proliferative Endometrium mean?
A proliferative endometrium is normally seen in the first half of a menstrual cycle when the inner lining of the uterus regrows and thickens after being shed as menstrual bleeding. Its presence during the second half of a menstrual cycle typically indicates a failure of the ovaries to release the developing egg. In women of a fertile age, the presence of a proliferative endometrium is diagnostic of anovulation (lack of ovulation) which is helpful in the evaluation of infertility. A proliferative endometrium can also be seen in patients who are taking estrogen and in women around and after menopause.
FertilitySmarts explains Proliferative Endometrium
During a menstrual cycle, the uterus also undergoes cyclical changes in response to changes in hormone levels in the blood, mainly estrogen and progesterone. The uterine cycle can be described in 3 stages:
- Menstruation: When the released egg is not fertilized, the corpus luteum slowly disappears and stops releasing progesterone. As a result, the uterus sheds the internal lining of the uterus, the endometrium that gives rise to menstrual bleeding.
- The proliferative phase: As the maturing ovarian follicle releases estrogen hormones, the endometrium responds by increasing the number and layers of cells and tissue. The endometrium grows and becomes thick during this phase.
- The secretory phase: After the release of an egg, a follicle turns into a corpus luteum and starts producing progesterone. The endometrium becomes rich in blood vessels and the glands in the endometrium releases substances that help to keep the integrity of the inner cell lining. The secretory phase prepares the uterus for the possible implantation of a fertilized egg.
The nature of the endometrium can be studied by obtaining a sample from the endometrium and then examining the cells under a microscope. This is called endometrial biopsy and can be performed by inserting an instrument into the uterine cavity through the vagina.
An evaluation of the endometrium is not the only test that can help in the diagnosis of anovulation. There are other less invasive blood tests and imaging studies that can give useful information about the state of ovulation, but an endometrial biopsy has the added advantage of being able to detect other abnormalities of the endometrium such as endometrial cancer.