This test is designed to evaluate the endometrial lining of the uterus and historically to obtain an objective assessment of ovulation or to rule out “luteal phase defect” (LPD). LPD is defined as either a short luteal phase (less than 12 days) which is the second part of the menstrual cycle after ovulation and until menstruation or inadequate progesterone production. Currently, LPD diagnosis is questionable and the practice of doing an endometrial biopsy solely to document ovulation is no longer acceptable. The most common reason for an endometrial biopsy is to rule out precancerous growth in the uterine cells called endometrial hyperplasia or endometrial cancer.
The test can be done anytime but preferably before ovulation (first part of the cycle) to avoid interference with a possible pregnancy in the uterus. Historically, it has been done in the second part of the cycle to document ovulation and changes in the endometrial cells. This approach was used to document any discrepancy in the morphological appearance of the cells compared to the days post-ovulation in the luteal phase and to diagnose LPD. Microscopic evaluation of the endometrial cells provides information regarding the luteal phase of the cycle, documentation of ovulation and secretory changes in the endometrium, and also regarding endometrial hyperplasia (precancerous endometrial cells) and endometrial cancer. In certain cases, it may be combined with hysteroscopy (camera to visualize the inside of the uterus) to allow a directed biopsy of a suspected lesion in the endometrial cavity.
A pregnancy test will be performed in the office before the biopsy is done, if the timing of the test corresponds to the luteal phase or in patients who have irregular menses. A speculum is then inserted into the vaginal cavity (similar to a pap smear preparation) and the cervix is cleansed with an iodine solution. A small flexible thin catheter is passed through the cervix and a tiny sample of the lining of the uterus is obtained. One may expect to have some menstrual cramps as the test is performed, but some women do not have any discomfort at all. The test itself is quite fast, and any discomfort that patients may have subsides rapidly.
We recommend that patients take pain medication (Tylenol or Motrin) one hour prior to the procedure. We also recommend that patients not skip breakfast or lunch, whichever meal prior to the time the test is scheduled because patients don’t need to fast for this procedure. This will reduce the chance of nausea, lightheadedness or fainting after the procedure, which are quite rare. Some women will have spotting for a few hours after the biopsy, which should not be perceived as the menses. The test results are generally available within 7-10 days. If you have not heard back regarding the biopsy results within two weeks following the procedure, you should call your doctor’s office to follow up.