Midwest Reproductive Center

Endometrial Biopsy

An endometrial biopsy (EN-doh-MEE-tree-al BY-op-see) is a test that evaluates the endometrial tissue that lines the inside walls of your uterus.

Around the time you ovulate (release an egg from your ovary), your endometrium (inside lining of your uterus) grows thick with blood vessels, glands, and stored nutrients to allow a fertilized egg to implant and grow. If fertilization does not occur, the endometrial tissue sheds as menstrual flow to mark the beginning of your next cycle. Progesterone and estrogen control the growth and stabilization of the endometrial tissue. If your body doesn’t produce enough of these hormones, your uterus may not be able to maintain a pregnancy. An endometrial biopsy is taken by your doctor and then sent to a pathologist who will examine the sample of your endometrial tissue under a microscope. Your doctor can tell if your body is producing enough of these hormones by its thickness and pattern. If your body is not producing enough hormones, medications may be prescribed to regulate them.

How this test is performed

Your doctor will place a speculum inside your vagina, insert a small catheter through your cervix into your uterus, and remove a small sample of the endometrial lining. It usually takes just a few seconds. You may feel a pinch or some cramping.

Questions & Answers

Q. What can I expect after the procedure?

A. You may have mild cramps an hour or so after the procedure and you may also have vaginal spotting. Light bleeding and spotting can last until you have your period.

Q. When will I receive the results of this test?

A. It may take as long as 7 to 10 days to prepare and interpret the biopsy.

Q. Does this test have to be done on a specific day of my cycle?

A. Yes. This test is usually done 1 to 3 days before you expect your period. Your endometrium should be very thick at this time in your menstrual cycle. You will need to let your doctor know when your period actually begins. Your doctor will compare the date your period actually started with the date it should have started, based on the thickness and pattern of the tissue sample. If there is a big difference between these dates, it may mean that your endometrium is not sufficient to support a pregnancy.

Q. What are the risks of this procedure?

A. There is a slight chance that the biopsy may disrupt an early pregnancy if you happen to be pregnant when the test is performed. To avoid this potential problem, your doctor may want you to avoid pregnancy during the month you are taking this test. You may also have to take a pregnancy test before you have the biopsy to make sure you’re not pregnant.