Endometrial biopsy

An endometrial biopsy removes a small sample of the endometrium, the tissue lining the inside of your uterus. The sample is examined under a microscope by a pathologist, a doctor who specializes in identifying changes in cells and tissues.

A clinician usually passes a thin, flexible tube through your vagina and cervix into your uterus. Suction draws a small amount of tissue into the tube. There is no skin incision.

The procedure is usually brief, but it can cause strong period-like cramps. Most people go home shortly afterward.

An endometrial biopsy helps find the reason for bleeding that is unusual for you. This may include bleeding after menopause, bleeding between periods, very heavy or prolonged periods, or bleeding patterns that have not improved with treatment.

The biopsy can look for:

• Endometrial hyperplasia, an overgrowth of the uterine lining
• Atypical cells, which have changes that may become cancerous
• Endometrial cancer
• Hormonal effects on the uterine lining
• Changes during follow-up of previously abnormal tissue

It may also be used in some fertility assessments, although it is not needed for everyone having difficulty becoming pregnant.

A biopsy samples only part of the lining. It may miss a small polyp or another abnormal area that occupies one spot. If bleeding continues despite a reassuring result, further testing may still be appropriate.

You may be offered an endometrial biopsy when your bleeding pattern, age, medical history, ultrasound findings, or risk factors make tissue testing useful. The goal is to find out whether the lining is normal or needs treatment.

The procedure should not be performed during a known or possible pregnancy because it could disrupt the pregnancy. Tell your healthcare team if pregnancy is possible, even if you have had some bleeding.

A biopsy may need to be delayed if you have an active pelvic or cervical infection. Symptoms such as fever, unusual discharge, or significant pelvic pain should be assessed first.

Extra planning may be needed if you:

• Take a blood thinner or have a bleeding disorder
• Have severe cervical narrowing
• Cannot tolerate a pelvic examination
• Have previously had a difficult or unsuccessful office biopsy
• Need sedation because of pain, anxiety, disability, or past trauma

In these situations, hysteroscopy or sampling under anaesthesia may be a better option. Hysteroscopy uses a small camera to look inside the uterus and take tissue from a specific area.

Your treating facility's own instructions take priority because preparation may differ based on your health and whether sedation is planned.

Tell the facility about all medicines and supplements you take, especially blood thinners like warfarin or apixaban. Do not stop a prescribed medicine unless the healthcare professional managing it gives you specific instructions.

Ask whether you should take pain medicine before the appointment. Do not exceed the label instructions or take a medicine that is unsafe for you.

Fasting is not usually needed for an office biopsy without sedation. If sedation or anaesthesia is planned, you may need to stop eating and drinking beforehand.

Before the appointment:

• Tell the team if pregnancy is possible
• Report allergies, bleeding problems, or infection symptoms
• Ask whether someone must drive you home
• Bring a sanitary pad for light bleeding afterward

You may be asked to provide a urine sample for pregnancy testing. The procedure can sometimes be done during menstrual bleeding, but contact the facility if the bleeding is unusually heavy.

You undress from the waist down and lie on an examination table with your feet supported. A clinician places a speculum in your vagina, similar to the instrument used for cervical screening. This allows them to see your cervix.

The cervix may be cleaned. A small instrument may be used to hold it steady. In some cases, the clinician measures the depth of the uterus or gently opens a narrow cervix.

A thin sampling tube is then passed through the cervix into the uterus. The clinician creates gentle suction and moves or rotates the tube to collect tissue. More than one pass may be needed.

You may feel pressure followed by a short period of strong cramping. Slow breathing and relaxing your pelvic muscles may help. Tell the clinician if you need them to pause.

The tube and speculum are removed. The tissue goes to a pathology laboratory. If the tube cannot enter the uterus or too little tissue is obtained, another procedure may be needed.

Pain: Period-like cramps are common for several hours. Mild cramping may continue into the next day. Use only the pain relief recommended for you.

Eating: You can usually eat and drink normally right away if you did not have sedation. Follow separate instructions after sedation or anaesthesia.

Activity: Light bleeding or spotting can occur for a few days. Use a pad so you can monitor it. Follow your facility's advice about tampons, sex, swimming, and strenuous exercise while bleeding.

Driving: You can usually drive if you had no sedative and feel able to brake and move comfortably. Do not drive after sedation or anaesthesia; arrange for someone to take you home.

Work: Many people return to work the same day or the following day. You may want more time if your work is physically demanding or your cramps are uncomfortable.

Cramping and light bleeding are expected effects rather than complications. Some people also feel dizzy, sweaty, or faint during or shortly after the biopsy.

Less common complications include:

• Infection of the uterus or pelvis
• Bleeding that is heavier or lasts longer than expected
• Injury to the cervix
• Perforation, meaning the instrument makes a small hole in the uterus
• An inadequate sample that does not provide an answer

Uterine perforation may require observation or additional treatment, particularly if there is ongoing pain or bleeding. Tell the team immediately if you develop severe pain during the procedure.

The pathology laboratory usually reports the result within several days to two weeks. Ask when and how the facility will contact you.

A result may show normal tissue, hormonal changes, a polyp, endometrial hyperplasia, atypical cells, cancer, or an insufficient sample. An insufficient sample means there was not enough tissue to make a reliable assessment; it does not by itself mean that something abnormal was found.

Follow-up may involve monitoring, medicine, hysteroscopy, another biopsy, or surgery. The next step is based on the result, your symptoms, ultrasound findings, and whether bleeding continues.

Keep routine follow-up appointments even if the result is reassuring. A blind biopsy can miss a small, localized abnormality, so persistent or recurring bleeding may need further evaluation.

The appropriate alternatives depend on why the biopsy was offered.

• Transvaginal ultrasound: A probe placed in the vagina measures the lining and looks for fibroids or other structural changes. It is less invasive but does not provide tissue or identify cell changes.
• Saline infusion sonography: Fluid placed inside the uterus improves ultrasound views of polyps and fibroids. It shows the shape of the cavity but does not usually provide a tissue diagnosis.
• Hysteroscopy with directed biopsy: A camera allows the clinician to see and sample a specific area. It is better for focal changes but involves more equipment and may require anaesthesia.
• Dilation and curettage: The cervix is opened and more tissue is removed. It can obtain a larger sample but is more invasive and is often performed with anaesthesia.
• Monitoring: In selected low-risk situations, symptoms and imaging may be followed without immediate biopsy. This avoids the procedure but may delay a definite tissue diagnosis.

Ask what information each option can provide and how choosing it might affect the timing of diagnosis or treatment.

Contact your healthcare team during routine hours if spotting or cramping lasts longer than your instructions indicated, your original bleeding continues, or you have not received results by the expected date.

Seek urgent same-day advice for:

• Fever or chills
• Worsening pelvic or abdominal pain
• Foul-smelling vaginal discharge
• Bleeding that rapidly soaks through pads
• Dizziness or weakness with ongoing bleeding

Call emergency services for very heavy bleeding with fainting, difficulty breathing, chest pain, confusion, or severe pain with collapse.

Will I be asleep for an endometrial biopsy?

Usually not. Most office biopsies are performed while you are awake without sedation. Local anaesthetic may be offered in some settings. Sedation or general anaesthesia may be used if an office biopsy is unsuitable.

Can I drive home afterward?

Usually, yes, if you did not receive sedation and feel well. You must not drive after sedation or general anaesthesia, so arrange an adult escort.

How painful is an endometrial biopsy?

Experiences differ. Many people feel brief, strong period-like cramps while the tissue is collected. Cramping usually eases quickly, although milder discomfort can continue afterward.

When will I know the results?

Pathology usually takes several days to two weeks. Your facility should tell you when to expect contact and whom to call if the result has not arrived.

Can a normal biopsy rule out cancer completely?

A reassuring biopsy lowers concern, but it may not detect every small or localized abnormality. Continued or recurrent bleeding may require hysteroscopy, imaging, or repeat sampling.

Will the biopsy affect my next period?

You may have spotting after the procedure, and your next period may come slightly earlier or later than expected. Contact your healthcare team if bleeding is much heavier than usual or remains abnormal.