Patient information from BMJ

Endometrial ablation (microwave method)

Last published:Jan 05, 2023

This information tells you about an operation to burn away the lining of your womb.

It explains: how the operation is done, how it can help, what the risks are, and what to expect afterwards.

You can use our information to discuss your treatment with the doctors and nurses caring for you.

What is endometrial ablation?

Endometrial ablation is an operation to destroy the lining of the womb. The endometrium is the medical term for the womb lining. Ablation means to destroy.

The microwave method is one of several types of endometrial ablation. The method you are offered will depend on what is used in your area, and perhaps on the particular expertise of your surgeon.

If you have microwave endometrial ablation, a surgeon uses heat to burn away the lining of your womb (uterus).

A long, thin instrument is carefully placed inside your womb through your vagina. It's heated up using microwaves, which destroy the womb lining.

Why might I need endometrial ablation?

To make your periods lighter

Endometrial ablation is a treatment for heavy menstrual periods. Heavy periods are a very common problem. Each year about 1 in 20 women see their doctor because of heavy periods.

Each month, the lining of your womb thickens. During your period your womb lining comes away and is passed through your vagina with some blood.

You lose about seven to eight teaspoonfuls of blood during a normal period. But during a heavy period you can lose more than twice that amount.

One way to reduce the amount of blood and tissue you lose is to remove the lining of your womb. It's not easy to measure exactly how much blood you, as an individual, lose during your period. But you and your doctor might think about an operation if you:

• use more than nine pads or tampons (or both pads and tampons) on your heaviest days

• have to wear both a tampon and a pad

• have periods that regularly last more than six days

• need to get up at night to change your protection

• pass clumps of blood (blood clots)

• stain your bedding or clothes despite wearing tampons and pads

• have 'flooding' (a sudden loss of lots of blood)

• stay at home or take time off work during your period. 

To make your periods less painful

Some women with heavy periods have a lot of pain each month. This is because the muscles in the womb tighten so that they can push out the thick lining. If the lining is thinner, your periods might be less painful.

To improve your quality of life

Heavy periods don't mean there's anything seriously wrong with you. But they can disrupt your life and make you feel miserable. For example, you might be more likely to:

• stay at home during your period because you are worried you won't get to a toilet in time to change your tampon or pad if you go out

• feel tired, especially during your period

• feel anxious or depressed, and

• have problems with your sex life.

Bleeding less might help you to feel better about yourself and allow your life to get back to normal.

Is endometrial ablation the right treatment for me?

Your doctor will probably only suggest this operation if treatment with medication hasn't made your periods lighter. Doctors usually recommend trying a drug treatment for at least three months before thinking about surgery.

Your doctor might suggest that you try an intrauterine device (IUD). This is a small device that’s fitted into your womb. It releases a hormone called progesterone, which helps reduce bleeding.

Your doctor probably won’t suggest surgery unless you have tried an IUD and it hasn’t helped.

Microwave endometrial ablation isn’t suitable for all women with heavy periods. You shouldn’t have this operation if:

• you want to get pregnant. Pregnancy is possible after this operation, but it’s unsafe for both mother and baby. Your womb lining will be too thin to give the baby the blood supply it needs to develop.

  There is also a chance that the baby will grow in the tubes that carry eggs from your ovaries to your womb (fallopian tubes). This is called an ectopic pregnancy. Ectopic pregnancies cannot develop safely and have to be terminated

• you want to be certain that your periods will stop. You'll need to have your womb removed (a hysterectomy) to guarantee this.

What will happen?

Preparing for the operation

A month before the operation, your doctor might give you a hormone treatment to thin your womb lining so it's easier to remove it. This might be a single injection or a course of pills.

If your operation is planned for just after your period, you might not need hormone treatment.

About one hour before the operation you'll be given a pain-killing drug. This is usually given as a pill that's put into your rectum through your anus (called a suppository), but you might be given a pill to swallow.

You will then have either a local anaesthetic (which means you won't feel anything during the operation, but you will be awake) or a general anaesthetic (which means you will be asleep during the operation).

If you have a local anaesthetic, your surgeon will inject your cervix (the opening of your womb) to make it numb. You or your surgeon might prefer a general anaesthetic, especially if you're anxious.

The operation

This operation should:

• shrink the womb lining by burning away the tissue

• make the blood in your womb lining sticky (it 'coagulates')

• destroy cells that help the lining to grow again each month. Without this layer of cells, the lining doesn't get so thick, so your periods are lighter.

The operation usually takes about 20 minutes. Most women are able to go home within a few hours. During the operation:

• the cervix is carefully widened so that the operating equipment can fit through. Instruments called dilators are put into your cervix, one at a time.

  The surgeon starts with a dilator 2 millimetres wide, and then replaces it with one 3 millimetres wide and so on, until your cervix is open to a width of 9 millimetres (about one-third of an inch)

• your surgeon will then insert a long, thin instrument into your vagina, then through your open cervix and into your womb

• you might have an ultrasound scan to check that the instrument is in the right place

• when the surgeon switches on the instrument, the microwaves come out of the tip and heat up the womb lining one area at a time. The tip has a heat sensor, and the temperature is displayed on a TV monitor.

  When the temperature reaches a certain point the surgeon knows that that part of the womb lining has been destroyed.

  The surgeon then moves on to the next area. The instrument is moved from side to side and gradually pulled out until all the lining of your womb has been destroyed.

If you feel any pain during the operation, the surgeon can give you another drug to help you relax (a sedative). Or you might be given pain-killing nitrous oxide (also known as 'gas and air') to breathe.

You won't need any stitches or dressings after this kind of surgery.

What are the risks?

All operations have risks, and your surgeon should discuss with you the risks of this operation before you have it.

You might be more likely to have problems with this operation if:

• the wall of your womb is thinner than usual, or

• you've had a caesarean section or other surgery on your womb that has left a scar.

If either of these applies to you, your doctor might advise you not to have this operation and to try different treatments instead.

Anaesthetics

One common side effect of surgery is nausea (feeling sick) caused by anaesthetics. But this goes away fairly quickly.

It is also possible, but rare, to have an allergic reaction to anaesthetics. It's important to tell your doctor before your operation if you have any allergies.

Other possible problems

Other complications can happen during or soon after this type of surgery. They include:

• damage to the womb. The instrument used in this operation can make a small hole (a perforation) in the womb. This is rare, and most perforations heal by themselves over time. But some women need surgery to repair the damage

• very heavy bleeding (haemorrhage). Some women bleed heavily during the operation or afterwards. If this happens, you might need a blood transfusion

• a large build-up of blood called a haematoma. If you bleed a lot during the operation, blood can form a solid swollen lump at the top of your vagina or in your abdomen. This lump might go down by itself, but some women need surgery to drain off the blood

• burns caused by the microwaves. These are rare but they can happen in your vagina, your cervix, or bowel. Burns to the bowel can be serious, and the damage will need to be repaired

• infection. This is a risk with any surgery. You might be given antibiotics after the operation to help prevent infection

• problems with the equipment. If the equipment doesn’t work properly during your operation, your surgery might take longer or be delayed.

Endometrial ablation works well for most women. But some women find that they have heavy periods again after a while.

This is because it’s sometimes hard to remove all the cells that help your womb lining grow. If some cells are left behind, then the lining can re-grow and your periods can become heavy again. Some women need more treatment within a year. 

Pain

You won't feel any pain during the operation, but you might be sore for a few days afterwards. Painkillers such as paracetamol or ibuprofen can help.

If you have a lot of pain after surgery it's important to tell the nurse or your doctor. It can be a sign of infection or of damage to your womb or other organs nearby. 

What can I expect afterwards?

If you had a local anaesthetic, you might feel well enough to go home within an hour of the operation. It takes longer to recover after a general anaesthetic, but you should still be able to go home the same day.

You'll need to stay at home and take it easy for a day or so. You might have some cramps (like bad period pains) that last for up to four hours after the operation.

Painkillers such as ibuprofen and paracetamol should help. Your doctor might also give you antibiotics to prevent infection.

You might feel a bit sore and uncomfortable the next day, but this rarely lasts for longer than a week. You will have a watery discharge from your vagina for about three weeks after the operation, but you might not have any bleeding.

Rules about driving vary from country to country, but in many places you can drive again the day after this surgery. You should check the rules where you live.

You should be back to your normal activities within a few days. But you might want to wait to have sex until the watery discharge has stopped.

It's harder to get pregnant after this surgery, but it does sometimes happen. You should continue to use your normal contraception.

Some women find that their periods stop completely after this surgery.