Intrauterine contraceptive device

An intrauterine contraceptive device (IUD) is used to prevent pregnancy. You can get copper IUDs or hormonal IUDs (Mirena or Jaydess). These sit inside your uterus (womb).

How intrauterine contraceptive devices work

An intrauterine contraceptive device (IUD) works by preventing fertilisation of the egg. The copper or hormone stops sperm moving through the uterus towards the egg. If your egg does receive the sperm, the IUD stops your egg from implanting in the wall of your uterus.

  • The copper IUD is 99% effective in preventing pregnancy. Only 1 person out of 100 will get pregnant each year.
  • Mirena is 99.5% effective in preventing pregnancy.

Most people are able to use an IUD including young people and people who have not had tamariki.

Mirena is particularly suitable for people with heavy periods.

Advantages of intrauterine contraceptive devices

There are many advantages to an intrauterine contraceptive device (IUD) which include:

  • they can stay in place for 5 years or more
  • it is possible to get pregnant as soon as the IUD is taken out
  • they do not interfere with sex
  • they are safe to use if you are breastfeeding
  • it is safe to use if you cannot take a contraceptive pill
  • you do not need to think about taking a pill everyday
  • most people have lighter periods and less period pain with Mirena — some have no periods at all
  • the copper IUD has no hormonal side effects.

Disadvantages of intrauterine contraceptive devices

There are some disadvantages to an intrauterine contraceptive device (IUD).

  • You have to have the IUD inserted. This is usually a simple, safe procedure. It is done by a doctor or nurse who is experienced at inserting IUDs. It takes about 5 to 10 minutes.
  • Most people have some cramps, like period cramps, at the time of insertion. Some people feel pain and may feel faint when the IUD is put in or taken out.
  • Cooper IUDs may cause heavier periods or cramping with your periods.
  • IUDs do not protect against sexually transmitted infections (STIs).

About 5% of the time, an IUD can come out by itself. You should check the strings are still in place after each period. It is also a good idea to do this 1 week after your IUD has been put in.

Contact your healthcare provider if you can feel the hard plastic of the IUD or if you cannot feel the string.

If you are not sure what to do call Healthline on 0800 611 116

Risks of intrauterine contraceptive devices

There are some risks from having an intrauterine contraceptive device (IUD) put in:

  • there may be a small chance of infection (about 1%) when an IUD is put in
  • there is a very small risk of damage or perforation of the uterus (about 1 in 1,000)
  • you may get pregnant with an IUD in place — but this is rare
  • any pregnancy can be ectopic (in the tubes) — this risk is less than in people not using any contraception
  • a copper IUD may cause more bleeding and cramping during periods
  • the copper IUD can very rarely cause an allergic reaction
  • Mirena may cause irregular, light bleeding for more days than usual when it is first put in.

Visit the Medsafe website for more information about Mirena's side effects.

Mirena — Medsafe (PDF 284KB) (external link)

Getting an intrauterine contraceptive device

Go to your doctor or a Sexual Wellbeing Aotearoa clinic if you decide to get an intrauterine contraceptive device (IUD).

The IUD is put into your uterus through your cervix. The procedure takes a few minutes and may be painful.

You may have some cramps for a couple of hours and some spotting, which could last for up to 2 weeks. You may also have heavy periods. This is not as common with the hormone type of IUD (Mirena).

To reduce the risk of infection after the insertion:

  • you should use sanitary pads (not tampons) for the first 48 hours
  • do not have sex in the first 48 hours.

The best time to fit an IUD is:

  • during or just after a menstrual period
  • 4 weeks after your pēpi is born
  • immediately after an abortion.

An IUD can also be used as an emergency contraception method after unprotected sex.

When to get medical advice

Removing your intrauterine contraceptive device

If you think you might be pregnant, see your healthcare provider to get your intrauterine contraceptive device (IUD) removed as soon as possible. There is an increased chance of miscarriage if the IUD is left in while you are pregnant.

If you decide you want your IUD removed, the best time is during your period. Your healthcare provider will remove the IUD by pulling the threads. This may be painful for a few seconds.

For more information, contact your healthcare provider or Sexual Wellbeing Aotearoa clinic.

Intrauterine device — Sexual Wellbeing Aotearoa (external link)

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