Information for you about Intrauterine Contraception or ‘Coils’


There are 2 main forms of intrauterine contraception:

  • The intrauterine device (IUD)
  • The intrauterine system (IUS)

Both forms are highly effective – over 99%.

They can be used for 5-10 years.

They are easily removed and should not affect your change of getting pregnant once they are taken out.

The IUS can reduce heavy or painful periods and can be used as part of HRT.

More about the IUD (also known as the copper coil):

The IUD has a plastic T-shaped frame coated with copper. It stops sperm reaching an egg by preventing sperm from surviving.  It may also stop the womb accepting a fertilised egg.  The IUD does not cause an abortion.  The IUD lasts for 10years and can then be removed or replaced with another IUD. It may be removed at any time.  It is important to remember that the IUD can make periods heavier, longer or more painful.

More about the IUS (also known as Mirena coil):

The IUS also has a plastic T-shaped frame but it has a coated sleeve with progesterone in it. There is a slow and steady release of the hormone into the womb. The IUS works mainly by thickening the mucus at the neck of the womb to stop sperm getting through. It also thins the lining of the womb so it is less likely to accept a fertilised egg.  The IUS works for 5 years and can then be removed or replaced with another IUS. It may be removed at any time. There is a risk of hormonal side effects although most women do not get any as the dose is so small and it mainly acts within the womb.  Side effects, if they do occur, usually settle after 2-3 months and may include breast tenderness, acne, mood changes and headaches.  It is common to get irregular light bleeding in the first 3-6 months of use.  After this, periods are usually much lighter and many women find they stop altogether.  This is ok; it is not bad for your health.

Which intrauterine device (coil) is best for me?

For most women the choice is yours!  Remember, if you have heavy painful periods the IUD is likely to make it worse, whereas the IUS may help.


Fitting an IUD or IUS is usually straightforward but it is important to be aware of the small risks involved.

  1. Infection – less than 1 in 100
    • Occurs usually within 3 weeks of fitting
    • The coil doesn’t cause infection but may push any infection already present in the vagina further up into the womb
    • If you feel you are at risk of sexually transmitted infections (STI) you should arrange an STI check before your fitting.
    • Having a coil fitted doesn’t increase your risk of STIs in the future, but remember it doesn’t protect you either and so you may need to use condoms as well.
  2. Expulsion or displacement – 1 in 20
    • Expulsion is when your womb pushes the device out
    • Displacement is when the coil moves into the wrong position
    • These are most common in the first 3 months but can happen at any time.  
    • You may not know it has happened so we advise you check your threads once a month.
    • If you cannot feel your threads please abstain from sex or use another method of contraception and book a check up.
  3. Ectopic pregnancy – 1 in 2000
    • No contraception is 100% effective but the IUD and IUS come close
    • If you do fall pregnant when using these methods there is a small chance the pregnancy attaches outside the womb – this is known as an ectopic pregnancy.
    • But remember, the risk of an ectopic pregnancy is far higher in women using no contraception at all.
    • If you do have symptoms of pregnancy you must do a pregnancy test right away and seek medical advice if it is positive.
  4. Perforation – 1-2 in 1000
    • This is uncommon but there is a small risk the device could go through the womb when it is put in.
    • This can cause pain but sometimes there are no symptoms
    • Pregnancy hormones make the womb more susceptible to perforation and the risk increases to around 6 in 1000.
    • If it happens the device may have to be removed by an operation.
    • The risk is very low when fitted by an experienced clinician.
  5. Other risks
    • There is a risk of period like pain during the procedure
    • There is a risk of vasovagal reaction (feeling faint)
    • There is a risk the coil cannot be inserted as occasionally the cervix goes into spasm and closes up


You should consider if you need an STI check to rule out any infections before your fitting.  This can be arranged by a local clinic or by ordering a home test kit.

Arrange a home test kit

Arrange an STI screen at a clinic

It is very important that there is no risk you could be pregnant before your coil is fitted.  If there is a risk that you might be pregnant then we may have to reschedule your fitting.

The timing of your fitting will depend on what contraception you are currently using:

If you are currently using a hormonal method (pill, patch, vaginal ring, injection and non-expired implant) then your device can be fitted at any convenient time and you can continue to use your current method correctly until your fitting.

If you are currently using condoms, diaphragm, natural methods of contraception or have an expired implant or expired IUD/IUS device then you have two options:

  1. Abstain from sex from day one of your period until your fitting (or abstain from sex for three weeks if your periods are irregular)
  2. Arrange to use a short-acting form of contraception, for example, pill, patch, vaginal ring, for at least four weeks before the fitting. You can contact us to arrange this by telephone consultation or e-consult

If you need to replace your current IUD/IUS device and it has not yet expired then this can be done on any convenient day. Please make sure you abstain from sex or use condoms for seven days before the fitting.

This is to make sure that you are not at risk of being pregnant if for some reason we cannot fit the new device after the original one is removed.

Preparation checklist

You will need to print a copy of our self-assessment checklist and bring a completed copy to your fitting appointment.  If you do not have access to a printer please arrive a few minutes early and ask the receptionist for a copy to complete while you are waiting.

On the day of your appointment

Where possible we will fit your device at your appointment.

However, there may be reasons why the fitting may need to be deferred. If this happens then the doctor or nurse who is seeing you will explain why.

On the day of your appointment:

  • Please arrive on time!
  • Please allow half an hour for the appointment. Although the procedure does not take this long, some women need a little more time to recover after the procedure.
  • We recommend that you eat and take pain relief before your appointment.
  • If you need to bring your child or children then you please bring someone to look after them while you are having the fitting.
  • Please bring sanitary protection, as you may experience some bleeding after the fitting.
  • We advise you to avoid driving immediately after your fitting.
  • You can still attend if you are bleeding, it is fine to have a coil inserted during your period.
  • If you are due a smear test we can do this at the same time (unless you are bleeding).


The device is fitted inside the womb by Dr Burtenshaw with an assistant, usually nurse Marie.  Sometimes we have medical students learning with us in the surgery.  It is useful for their learning to observe these procedures but if you do not feel comfortable with them being present please just let us know.

The procedure takes about 10-15 minutes. Before the fitting you will have an opportunity to ask any questions and we will go through your completed checklist to confirm you understand the small risks involved.

We may ask you to provide a urine specimen to make sure that you are not pregnant before we begin. 

Before the fitting you will usually be examined internally to check the position of the womb.  If you are due a smear test this can also be done at this point. 

We use a speculum – a plastic device – to get a good view of your cervix, just like during a smear test.  This does not hurt. The cervix is held still with a small forcep to reduce the risk of perforation and the size of the womb is checked.  The coil can then be inserted.  

The fitting can be mildly uncomfortable for some women and you may choose to take simple pain relief before you attend.  Paracetamol or ibuprofen are both suitable. 

You may get period like cramping and light bleeding for a few days after the procedure.  You may like to bring a pantyliner or sanitary towel with you to wear home. 

After your procedure:

How soon your coil is effective depends on the type of coil and the type of contraception you were using before the fitting.  We will discuss this at your appointment.

It is fine to have sex, use tampons and have a bath after having a coil fitted.  However, as the risk of expulsion or displacement is highest soon after fitting some women prefer to wait until their next period before using tampons. 

You should check your coil threads about once a month and after any bleeding.  There are 2 threads attached to the bottom of the coil that come through the cervix and sit high up in the vagina.  To check your threads:

  • Wash your hands
    • Sit or squat down
    • Insert your index or middle finger into your vagina until you touch your cervix (which feels like the tip of your nose)
    • If you can feel the threads then your coil is in place
    • If the threads feel longer or shorter than last time, or you cannot feel them at all then your coil may have come out or moved.  
    • Until you can see the nurse of GP you should make sure you abstain or use another method of contraception

Your coil threads may be felt by your partner during sex.  This is fine, but if they are too long and causing discomfort they can be trimmed by the GP.  However, this makes it harder for you to check them and increases the risk that the coil cannot be easily removed in future.

You can book a check up 6-8 weeks after your fitting if you have any questions or concerns.  This is not compulsory and some women, particularly if they have used this method before, feel confident to check their threads themselves.

How do I book an appointment?

Please complete an econsult or speak to reception who will pass your details to Dr Burtenshaw.  She will then contact you by phone to check which coil you wish to have and arrange an appointment with you.  Please ensure we have your correct contact details.