Intrauterine Contraceptive Device

The intrauterine contraceptive device (IUCD) is an effective method of contraception which is also known as 'the coil'. It sits inside the womb (uterus). Once fitted, it can stay in your womb for up to ten years. Most women who use an IUCD have no problems with it. The device is called a coil because in the 1960s some devices were coil-shaped.

An IUCD is a small device made from plastic and copper which sits inside the womb (uterus). It is also known as 'the coil'. There are two threads attached to the IUCD which pass out through the neck of the womb (cervix) and lie in the vagina (see diagram below). These allow the IUCD to be removed easily. Most devices are T-shaped (the two arms fold flat for insertion) and are about as long as a match stick. The inside of the womb itself is only a little longer than a matchstick, so the device sits neatly inside.

An IUCD can be placed quite easily into the womb by a trained doctor or nurse.

It works mainly by making it difficult for sperm to fertilise an egg. This is an effect of the copper in the device. It makes the mucus at the neck of the womb (cervix) and the womb lining itself hostile to sperm and eggs. This means that it prevents sperm getting in through the cervix, and from travelling through the womb. It also makes your womb lining much less likely to accept an egg.

Modern IUCDs are very effective. Only 1-2 of every 100 women using the IUCD as contraception will become pregnant over five years of use. Compare this with rates of pregnancy when no contraception is used. More than 80 in 100 sexually active women who do not use contraception become pregnant within one year, and this figure rises to 95 in two years.

There are many different types of IUCD. Most copper IUCDs will work well for at least five years. Some types work for ten years.

Once an IUCD is inserted you no longer need to use other contraception. So, unlike users of the contraceptive pill, you don't need to think about contraception every day. The IUCD does not interfere with sex or sex drive (libido). It is not a hormonal method so it has no side-effects on the rest of the body. This means that it will not affect your mood, weight or libido. Having an IUCD does not increase your risk of having any type of cancer in the future.

Because it does not contain chemicals called hormones, if they wish to, most women can have an IUCD. There are a few situations where an IUCD is not recommended, such as undiagnosed, irregular vaginal bleeding and pelvic infection. Your doctor or nurse will make sure it is safe for you to use an IUCD, by asking questions about your health.

Although the majority women with an IUCD have no problems, the following may occasionally occur:

Heavy, painful periods

Some women find that their periods become heavier, longer or more painful with an IUCD. This tends to be in the first few months after insertion and then often settles. This means that the IUCD may not be suitable if you already have heavy or painful periods. There is a special intrauterine contraceptive called the intrauterine system (IUS), which is like an IUCD, but it also releases a hormone into the womb (uterus). This is an effective treatment for heavy periods as well as a contraceptive. (See separate leaflet called Intrauterine System.)

If you have painful, heavy periods with an IUCD in place this can still be treated in the same way as in women who do not have an IUCD. For example, your doctor may prescribe anti-inflammatory painkillers or other medicines to take just before and during your periods.


There is a small risk of an infection of the uterus (pelvic infection) when you have an IUCD inserted. The main risk of infection is within the first 20 days after insertion. A check for infection of the vagina or neck of the womb (cervix) may be advised by taking a sample (swab) before an IUCD is inserted. You should not have an IUCD inserted if you have an infection which has not been treated.

Ectopic pregnancy

The chance of becoming pregnant is very small if you use an IUCD. However, if you do become pregnant, there is a risk of having an ectopic pregnancy (a pregnancy in the Fallopian tube and not in the uterus). This is rare, but if untreated can be serious.

The IUCD does not cause ectopic pregnancy. However, whilst it is very effective at preventing intrauterine pregnancy, it is less effective at preventing ectopic pregnancy. This means that those pregnancies that do develop with an IUCD in the uterus have a significant chance of being ectopic. See a doctor urgently if you miss a period (or your period is light and prolonged) and you develop lower, one-sided tummy (abdominal) pain.


Rarely the IUCD may come out without your noticing. This may happen during a period, most commonly in the first three months after fitting. It is slightly more likely to happen if you have not had children or if the fitting was particularly uncomfortable.

It is a good idea to check you can feel the threads of the IUCD after your period. If you cannot feel them, you should use extra precautions such as a condom, until your doctor has checked the IUCD is still there.

If the IUCD has come out in the last few days you may need emergency contraception. If the IUCD  could have come out more than a few days ago, and you are sexually active, the doctor will make sure you are not already pregnant before fitting another one or starting alternative contraception.

Damage to the womb

The fitting of an IUCD can very rarely make a small hole in the womb - this is called perforation. It protrudes through the wall of the womb and can escape into the pelvis. This happens in fewer than 2 women per 1,000, usually at the time of fitting. It can cause pain, but this is not usually severe and often there is not pain. The main symptom is not being able to feel the threads.

You should tell your doctor or nurse if you can no longer feel the threads of your IUCD. This can mean perforation has occurred. However, more commonly it means either that the threads are tucked up inside the neck of the womb (cervix) or (less commonly) the threads have come off the device. An ultrasound scan will be carried out to find a lost IUCD. If ultrasound does not find the IUCD, an X-ray will be ordered.

This is usually done towards the end of a period or shortly afterwards, as this tends to be more comfortable for you. Also, the doctor can be sure that you are not pregnant. However, it can be fitted at any time provided that you are certain you are not pregnant. You will need to have a vaginal examination. The doctor or nurse will pass a small instrument into your womb (uterus) to check its size and position. The IUCD is then fitted using a small plastic insertion device. You will be taught how to feel the threads of the IUCD so you can check it is in place. It is best to check the threads regularly - for example, once a month just after a period.

Female reproductive organs
IUCD in place

Fitting an IUCD can sometimes be uncomfortable. Once the IUCD has been inserted, some women have crampy pains like period pains for a few hours (and up to 48 hours) afterwards. These can be eased by painkillers such as paracetamol or ibuprofen, and it can be sensible to take these an hour before your fitting. Light vaginal bleeding may also occur for a short while.

Does the IUCD work immediately?

The IUD is immediately effective as a contraceptive.

The doctor or nurse will usually want to check that there are no problems a few weeks after fitting an IUCD. It is best done after your next period. After this, there is no need for any routine check until it is time to remove the IUCD. However, return to see your doctor or nurse at any time if you have any problems or queries. Most women have no problems, and the IUCD can remain in place for several years.

An IUCD can be removed at any time by a trained doctor or nurse. If you plan to have it removed, but do not want to get pregnant, then you should abstain from having sex (intercourse). Or, you should use other methods of contraception (such as condoms) for seven days before the IUCD is removed. This is because sperm can last up to seven days in the womb (uterus) and can fertilise an egg after the IUCD is removed.

If you have had your IUCD for its maximum effective time (usually five or ten years, depending on the device), and you need therefore to have it changed for another one, you should again abstain from having sex. Or, you should use other forms of contraception for seven days before removal. This is because occasionally when the device is removed, the neck of your womb (cervix) clamps tightly shut for a while. The doctor cannot therefore immediately insert the new device. As sperm can last up to seven days in the womb they could, therefore, fertilise an egg whilst you are waiting for your replacement IUCD fitting.

You can use sanitary towels or tampons for periods with an IUCD in place. A cervical smear can also be taken with an IUCD in place. Sometimes, the smear result may show that there is an organism in the cervix; these are called actinomyces-like organisms. These are normally found in the vagina and do not mean the IUCD should be removed. If you have had pelvic pain together with signs of infection, such as a temperature, your doctor may consider removing the IUCD.

You should consult a doctor if any of the following occur:

  • Prolonged tummy (abdominal) pain (severe or beyond 48 hours) after an IUCD is inserted.
  • A delayed period, or bleeding between periods.
  • A delayed period and lower or one-sided abdominal pain (which may be due to an ectopic pregnancy).
  • Vaginal discharge with or without pain (which may indicate infection).
  • If you suspect that the IUCD has come out or is coming out. It is usually possible to feel the threads of the IUCD inside the vagina to check it is in place. If you cannot feel the threads then use other contraceptive methods (such as condoms) until you have been checked by a doctor or nurse.
Now read about Intrauterine Contraceptive Device

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Dr Mary Lowth
Peer Reviewer:
Prof Cathy Jackson
Document ID:
4285 (v41)
Last Checked:
02 April 2014
Next Review:
01 April 2017
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