IUD (Intrauterine device): your guide

An IUD is a small plastic and copper device that is put into your uterus (womb). It has one or two threads on the end. These thin threads hang through the opening at the entrance of your uterus (cervix) into the top of your vagina.

There are different types and sizes of IUD to suit different women. An IUD can stay in for 5–10 years, depending on type. If you are aged 40 or older when the IUD is fitted, it can be left in until the menopause. It should only be fitted by a trained doctor or nurse. An IUD is sometimes called a ‘coil’.

Read this information to find out:

• What is the difference between an IUD and an IUS?
• How effective is an IUD?
• When will the IUD start to work?
• How does an IUD work?
• What are the advantages of an IUD?
• What are the disadvantages of an IUD?
• Are there any risks?
• Can anyone use an IUD?
• Where can I get an IUD?
• How is an IUD put in?
• What if I feel unwell after the IUD is put in?
• How will I know that the IUD is still in place?
• Is it safe to use tampons if I have an IUD fitted?
• When can the IUD be removed?
• Will an IUD affect my periods?
• What if I become pregnant while I am using an IUD?
• I've just had a baby. Can I use an IUD?
• Can I use an IUD after a miscarriage or abortion?
• How often do I need to see a doctor or nurse?

What is the difference between an IUD and an IUS?

An intrauterine system (IUS) is a small plastic device that is inserted into the uterus and slowly releases a hormone called progestogen. An intrauterine device (IUD) is a small plastic and copper device that does not contain any hormone.

How effective is an IUD?

How effective any contraceptive is depends on how old you are, how often you have sex and whether you follow the instructions.

If 100 sexually active women don’t use any contraception 80 to 90 will become pregnant in a year.

There are different types of IUDs. Newer IUDs contain more copper and are the most effective – over 99 per cent effective. This means less than two women in 100 will get pregnant over five years. Older IUDs have less copper and are less effective.

The IUD is a long-acting reversible method of contraception. All long-acting methods are very effective because while they are being used you do not have to remember to take or use contraception.

When will the IUD start to work?

An IUD can be put in at any time in your menstrual cycle if it is certain that you are not pregnant. It will be effective immediately.

How does an IUD work?

The main way an IUD works is to stop sperm reaching an egg. It does this by preventing sperm from surviving in the cervix, uterus or fallopian tube.

It may also work by stopping a fertilised egg from implanting in the uterus.

An IUD does not cause an abortion.

What are the advantages of an IUD?

• It works as soon as it is put in.
• It works for 5–10 years depending on type (but can be taken out sooner).
• It can be used if you are breastfeeding.
• Your fertility returns to normal as soon as the IUD is taken out.
• It is not affected by other medicines.

What are the disadvantages of an IUD?

• Your periods may be heavier, longer or more painful. This may improve after a few months.
• You will first need an internal examination to check the IUD is suitable, and another when it is fitted.
• The IUD does not protect you from sexually transmitted infections, so you may have to use condoms as well. If you get an infection when an IUD is in place this could lead to a pelvic infection if it is not treated.

Are there any risks?

• There is a very small chance of you getting an infection during the first 20 days after an IUD is put in. You may be advised to have a check for any possible existing infection before an IUD is fitted.
• The IUD can be pushed out by your uterus (expulsion) or it can move (displacement).This is not common. This is more likely to happen soon after it has been put in and you may not know it has happened. This is why your doctor or nurse will teach you how to check your IUD threads every month.
• It is not common, but there is a risk that an IUD might go through (perforate) your uterus or cervix when it is put in. This may cause pain but often there are no symptoms. If it happens, the IUD may have to be removed by surgery. The risk of perforation is low when an IUD is fitted by an experienced doctor or nurse.
• If you do become pregnant while you are using an IUD there is a small increased risk of you having an ectopic pregnancy (see What if I become pregnant while I am using an IUD?).The risk of ectopic pregnancy is less in women using an IUD than in women using no contraception at all.

Can anyone use an IUD?

Most women can use an IUD, including women who have never been pregnant and women who are HIV positive. Your doctor or nurse will need to ask you about your medical history to check if the IUD is suitable for you. Do mention any illness or operations which you have had as some may require specialist care when the IUD is fitted.

Some of the conditions which may mean you should not use an IUD are:

• you think you might already be pregnant
• you and your partner are at risk of getting a sexually transmitted infection.

You have:

• an untreated sexually transmitted infection or pelvic infection
• problems with your uterus or cervix
• unexplained bleeding from your vagina (for example, between periods or after sex).

Where can I get an IUD?

You can go to a contraception or sexual health clinic or to a doctor or nurse at a general practice. Some doctors and practice nurses will fit IUDs, but not all (see How to get help with your sexual health).

How is an IUD put in?

The IUD is fitted inside the uterus. The doctor or nurse will examine you internally to find the position and size of your uterus before they put in an IUD. Sometimes they will check for any possible existing infection. It is best to do this before the IUD is put in. In some circumstances you may be given antibiotics at the same time as the IUD is fitted.

Fitting an IUD takes about 15–20 minutes. It can be uncomfortable, or painful for some women, and you might want to use a local anaesthetic. Your doctor or nurse should talk to you about this beforehand. You may get a period type pain and some light bleeding for a few days after the IUD is fitted. Pain relieving drugs can help with this.

What if I feel unwell after the IUD is put in?

If you feel unwell and have any pain in your lower abdomen, with a high temperature or a smelly discharge from your vagina, see a doctor or go back to the clinic where it was fitted as soon as possible. You may have an infection.

How will I know that the IUD is still in place?

An IUD has one or two threads attached to the end that hang a little way down from your uterus into the top of your vagina. The doctor or nurse will teach you how to feel the threads to make sure the IUD is still in place. You should do this a few times in the first month and then after each period or at regular intervals.

It is very unlikely that an IUD will come out, but if you cannot feel the threads, or if you think you can feel the IUD itself, you may not be protected against pregnancy. See your doctor or nurse straight away and use an extra contraceptive method, such as condoms. If you had sex recently you might need to use emergency contraception.

Rarely, a partner may say they can feel the threads during sex. If this is the case, get your doctor or nurse to check the threads.

Is it safe to use tampons if I have an IUD fitted?

Yes, you can use either tampons or towels.

When can the IUD be removed?

A trained doctor or nurse can take the IUD out at any time, by pulling gently on the threads. If you are not going to have another IUD put in, and you don’t want to become pregnant, use an extra contraceptive method, such as condoms, for seven days before the IUD is taken out. This is to stop sperm getting into your body. Sperm can live for up to seven days inside your body and could cause a pregnancy once the IUD is removed. Your fertility returns to normal as soon as the IUD is taken out.

If you want to try for a baby start pre-pregnancy care such as taking folic acid and stopping smoking. You can ask your doctor or nurse for advice.

Will an IUD affect my periods?

You may have spotting (bleeding between periods), light bleeding, heavier or longer periods in the first six months after you have had the IUD fitted.

Some women have heavier, longer and more painful periods. This may improve over time. If you have prolonged bleeding it may be possible for the doctor or nurse to give you additional hormones or medicine that can help control the bleeding. They may also check the bleeding is not due to other causes such as infection.

You may wish to consider using a hormone releasing IUD (called an intrauterine system (IUS)) which will reduce bleeding and pain.

What if I become pregnant while I am using an IUD?

Very few women become pregnant while using an IUD. If you do become pregnant there is a small increased risk of having an ectopic pregnancy. An ectopic pregnancy develops outside the uterus, usually in a fallopian tube. If you think you might be pregnant and/or have a sudden or unusual pain in your lower abdomen, seek medical advice as soon as possible. This might be the warning sign of an ectopic pregnancy.

If you are pregnant the IUD should be removed as soon as possible, whether or not you wish to continue with the pregnancy. If you want to continue the pregnancy, removing the IUD can increase the risk of miscarriage.

I've just had a baby. Can I use an IUD?

An IUD is usually put in from four weeks after a vaginal or caesarean birth. You will need to use another method of contraception from three weeks (day 21) after the birth until the IUD is put in. It can also be put in within 48 hours of birth.

An IUD can be used safely while you are breastfeeding and will not affect your milk supply.

Can I use an IUD after a miscarriage or abortion?

An IUD can be put in by an experienced doctor or nurse immediately after a miscarriage or abortion. You will be protected against pregnancy immediately.

How often do I need to see a doctor or nurse?

You should have your IUD checked 3–6 weeks after it is put in. An IUD can stay in for 5–10 years depending on type, or longer if you have it put in over the age of 40. Do contact your doctor or nurse if you have any problems, questions or want it removed. It’s important to seek advice if you think you could be at risk of getting a sexually transmitted infection, as this can lead to a pelvic infection.