An endometrial biopsy is a medical procedure where some tissue from the inner lining of the womb (uterus) is removed, and then examined under a microscope. It is a short day-case procedure. The sample is taken with a tube which is passed through the vagina.
What is an endometrial biopsy for?
The point of an endometrial biopsy is to check the lining of the womb. Most commonly, this is done to check abnormal vaginal bleeding. For example in women who have bleeding after their menopause, or bleeding between their menstrual periods. The test is done to make sure the abnormal bleeding is not caused by cancer of the uterus (endometrial cancer). It is also to look for a thickening of the lining of the womb, called endometrial hyperplasia. Most times, when this test is done, it shows that there is no cancer, but it is important to be sure.
An endometrial biopsy is also sometimes done in women who are having treatment for infertility. In this case, the biopsy is to see if the lining of the womb has grown enough to be ready for a fertilised egg to be implanted.
What does the procedure involve?
An endometrial biopsy is a very quick test, and takes about 10 to 15 minutes. It is done as an outpatient procedure, in a hospital or community clinic, or sometimes a GP surgery.
You will be asked to undress from the waist down and to lie on the examination couch with your knees bent and your legs apart. It is similar to having a smear test. Also, as in a smear test, a plastic instrument called a speculum is put into your vagina to open it up. The health professional doing the biopsy will then be able to see the neck of the womb (cervix) at the end of the speculum. A local anaesthetic is sometimes applied to the cervix. Sometimes a forceps-type instrument called a tenaculum is used to grip the cervix and hold it steady.
A thin tube is then passed through the speculum in your vagina, through the cervix and into the womb. Most commonly the type of tube used currently is a Pipelle® cannula, although there are other types. The tube is moved up and down the inside lining of the womb, and sucks up some tissue as it does so. This is done a number of times to reach several parts of the lining of the womb. This tissue is then placed in liquid (called formalin) to preserve it until it reaches the lab where it will be examined under the microscope.
Once the sample has been taken, the speculum is removed, and you can get dressed and go home.
Will it hurt?
For most women it is not very painful, but let's be honest, it won't be fun. As when you have a smear test, it is not very dignified, and rather uncomfortable. If you can manage to relax the muscles of your vagina as the speculum is inserted, it is less uncomfortable. Those muscles are under your control (try it now!) and if they are not squeezed tightly shut, the speculum will pass more easily. It may be painful as the tube is passed through your cervix, and you may feel a cramping pain as the sample is being taken from the lining of the womb. It is exactly the same pain as a period, because the pain is caused by the same muscles of the uterus contracting. So for most women this is familiar and bearable.
You may continue to have some period-like cramping pains for a day or so afterwards, and if you need a painkiller you can use whatever you normally use for period pains. For example ibuprofen, or paracetamol.
How will I feel after an endometrial biopsy?
As above, you may have some crampy period pains in the lower part of your tummy on and off for a day or two after the procedure. You may also have some light bleeding, like a period. This does not usually last longer than a few days. Use a sanitary towel if you need one.
You should be able to drive straight after the procedure and go about your normal day.
Are there any complications?
It is very unusual to have complications after an endometrial biopsy. Rarely, the tube used can go right through the womb wall (perforate it). Occasionally there can be a lot of bleeding afterwards. Occasionally an infection can develop afterwards.
If you experience severe pain, have a lot of bleeding, or develop a smelly discharge or fever in the week after the procedure, then see your doctor urgently.
How long do the results take?
This will depend on your local laboratory, but usually takes between one and four weeks. The health professional who did the test will usually notify you of the result. They would normally tell you at the time of the biopsy how this will happen - it might be by phone, by letter, or in person at your next appointment.
Who can't have an endometrial biopsy?
In certain circumstances, an endometrial biopsy is not advisable. This includes:
- If you are pregnant.
- If you have a condition which causes you to bleed more easily, such as problems with your blood clotting system.
- If you have an infection of your womb, cervix, vagina or pelvis.
Further reading and references
Dickson JM, Delaney B, Connor ME; Primary care endometrial sampling for abnormal uterine bleeding: a pilot study. J Fam Plann Reprod Health Care. 2017 Oct43(4):296-301. doi: 10.1136/jfprhc-2017-101735. Epub 2017 Aug 19.
Narice BF, Delaney B, Dickson JM; Endometrial sampling in low-risk patients with abnormal uterine bleeding: a systematic review and meta-synthesis. BMC Fam Pract. 2018 Jul 3019(1):135. doi: 10.1186/s12875-018-0817-3.