An endometrial biopsy is a way for your doctor to take a small sample of the lining of the uterus (endometrium). The sample is looked at under a microscope for abnormal cells. An endometrial biopsy helps your doctor find any problems in the endometrium. It also lets your doctor check to see if your body's hormone levels that affect the endometrium are in balance.

The lining of the uterus changes throughout a woman's menstrual cycle. Early in the menstrual cycle, the lining grows thicker until a mature egg is released from an ovary (ovulation). If the egg is not fertilized by a sperm, the lining is shed during normal menstrual bleeding.

There are several ways to do an endometrial biopsy. Your doctor may use:

• A soft, straw-like device (pipelle) to suction a small sample of lining from the uterus. This method is fast and is not very painful.
• A sharp-edged tool called a curette. Your doctor will scrape a small sample and collect it with a syringe or suction. This is called a dilation and curettage (D&C). A D&C may be done to control heavy uterine bleeding (hemorrhage) or to help find the cause of bleeding. This is done with general or regional anesthesia.
• An electronic suction device (Vabra aspiration). This method can be uncomfortable.
• A spray of liquid (jet irrigation) to wash off some of the tissue that lines the uterus. A brush may be used to remove some of the lining before the washing is done.

When a woman is having a hard time becoming pregnant, an endometrial biopsy may be done to see whether the lining of her uterus can support a pregnancy.

An endometrial biopsy may also be done to find the cause of abnormal uterine bleeding, to check for overgrowth of the lining (endometrial hyperplasia), or to check for cancer.

An endometrial biopsy is sometimes done at the same time as another test, called hysteroscopy, which allows your doctor to look through a small lighted tube at the lining of the uterus.

Why It Is Done

An endometrial biopsy is done to:

• Check for cancer. For example, an endometrial biopsy may be done to help determine the cause of some abnormal Pap test results.
• Find the cause of heavy, prolonged, or irregular uterine bleeding. It is often done to find the cause of uterine bleeding in women who have gone through menopause.
• See whether the lining of the uterus (endometrium) is going through the normal menstrual cycle changes.

How To Prepare

Tell your doctor if you:

• Are or might be pregnant. An endometrial biopsy is not done during pregnancy.
• Are taking any medicines.
• Are allergic to any medicines.
• Have had bleeding problems or take blood-thinners, such as aspirin or warfarin (Coumadin).
• Have been treated for a vaginal, cervical, or pelvic infection.
• Have any heart or lung problems.