First the Facts

  • An intrauterine contraceptive device (IUD) is a small, T-shaped, plastic device with copper on the stem and sometimes also the arms
  • Copper is toxic to sperm and thus prevents fertilization and pregnancy from occurring
  • It sits inside the womb and is also known as the ‘copper coil’
  • Over 99% effective
  • Lasts 5–10 years depending on the type
  • Fitted and removed by a specialist doctor or nurse
  • Does not protect against sexually transmitted infections (STIs)

IUD birth control copper coil device, used for contraception (Foto:

How Does It Work?

  • The IUD contains copper which destroys sperm and eggs, preventing fertilisation
  • It also prevents pregnancy from developing in the lining of the womb
  • It is generally safe and does not normally cause any harm or damage to the womb
  • There are several types of IUD available
  • Less than 1 person per 100 users will fall pregnant within a year

Does It Work Straight Away?

Once fitted, the IUD works straight away:

  • It can be fitted at any time during your cycle as long as you are not already pregnant from unprotected sex earlier in your cycle
  • It is the best method of emergency contraception and can be used up to 5 days after multiple episodes of unprotected sex or 5 days after the predicted time of ovulation, because it can prevent a fertilized egg from implanting
  • It can be fitted 4 weeks after childbirth or within the first 48 hours of delivery. You cannot get pregnant within 21 days of childbirth, but you must use additional contraception after this time until the IUD is fitted
  • It can be inserted following complete miscarriage or abortion and works straight away

Are There Any Side Effects?

  • There are no hormonal side effects from the IUD and your periods should remain the same
  • Irregular bleeding can occur, especially in the first few months. This usually settles with time
  • Occasionally periods can become heavier and more painful
  • Future fertility is not affected by the IUD; you can become pregnant as soon as it is removed
  • There is a small risk of infection and/or damage to the womb when it is fitted
  • Rarely, the IUD can get stuck in the womb or fall out
  • Although the IUD is very effective, if a pregnancy did occur, there is increased risk this would be an ectopic pregnancy. This is when a pregnancy develops outside the womb, such as in the fallopian tube

How Is It Fitted?

  • A specialist nurse or doctor will fit the IUD for you
  • You will be examined to assess the size and position of your womb
  • A speculum is used to open the vagina and visualise the cervix (neck of the womb)
  • The IUD is gently inserted through the cervix and into the womb
  • A local anaesthetic can be used so you do not feel any pain
  • The procedure is very quick and will only take a few minutes
  • You may experience some cramping and bleeding afterwards, but this will settle down in a few days
  • Rarely, the IUD can damage the wall of the womb. This is called perforation

How Do I Know It Is in the Correct Place?

  • The IUD contains two soft threads attached to the bottom of the device
  • These threads pass through the cervix and sit at the top of the vagina
  • Your partner will not be able to feel the threads during sexual intercourse
  • You can check the IUD is still in place by inserting a finger into the top of the vagina and feeling for the threads
  • It is important to regularly check your threads so that you know the IUD is still in place
  • If you can no longer feel the threads, speak to your doctor and use another method of contraception until it can be identified. This is because the IUD might have fallen out

When Is It Removed?

  • The IUD provides contraception for 5–10 years depending on the type of device
  • You will be provided with written information advising you when your IUD needs to be changed
  • A specialist nurse or doctor can remove the IUD at any time
  • A speculum is used to find the threads of the IUD. It is removed by gently pulling on the threads

Where Can I Get an IUD Fitted/Removed?

You can get an IUD fitted free of charge at:

  • A sexual health, genitourinary medicine or contraception clinic
  • Some young person’s clinics
  • Some GP surgeries

Is It Right for Me?

The IUD is safe to use in the majority of users; however, there are some circumstances where it may not be appropriate.

Always discuss with the doctor or nurse if:

  • There is a chance you are already pregnant
  • You have symptoms of infection or have been recently diagnosed with an STI such as chlamydia or gonorrhoea
  • Your periods are usually very painful or heavy
  • Your womb is an abnormal shape
  • You have a history of cervical or womb cancer
  • You have bleeding in between your periods or after sex which has not been investigated


Written by: Dr David Rook and Dr Paula Briggs
Last updated: January 2021

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