Intrauterine contraceptive device (IUD)

  • An intrauterine contraceptive device (IUD) is one of the ‘fit and forget’ long-acting reversible contraceptive methods (LARC’s).
  • It is inserted into the uterus to prevent pregnancy.
  • There are 2 types available in Australia – the hormonal IUD and the copper IUD.

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What are IUDs?

An IUD is a small device which is fitted inside the uterus by a health practitioner, where it can remain for lengthy periods to prevent pregnancy. Once inserted, IUDs are not felt by the individual. IUDs have fine nylon threads attached to the lower end of them so that when fitted, the threads extend through the cervix (neck of the womb) into the upper vagina. These threads allow the individual to check that the IUD is still in place and allow for easy removal by a health practitioner

What types of IUDs are there?

Hormonal IUDs: 

  • Mirena® and Kyleena® are the brand names for IUDs which release progestogen.
  • They are T-shaped, made of plastic and steadily release small amounts of progestogen directly into the uterus.
  • Kyleena® has a lower dose of progestogen and the device size is smaller than Mirena®.
  • Mirena is effective at reducing heavy menstrual bleeding.
  • Both are effective for 5 years. 

Copper IUDs:

  • Copper IUDs are made of plastic and copper.
  • There are 2 types of copper IUDs currently available in Australia: the Copper T and Copper Load.
  • In some circumstances, a copper IUD can be inserted up to 5 days after unprotected sex to prevent pregnancy occurring.

How do IUDs work?

Hormonal IUDs work by:

  • thickening cervical mucus to prevent sperm penetration •
  • inhibiting sperm migration to the upper genital tract •
  • interfering with egg survival •
  • causing endometrial changes including thinning •
  • preventing ovulation in some users (ovulation is more likely to be suppressed in early cycles than with longer duration of use).

Copper IUDs work by:

  • inhibiting sperm migration to the upper genital tract •
  • interfering with egg survival •
  • preventing implantation

How effective is an IUD?

All types of IUDs are highly effective.

Of 500 individuals using a copper IUD for 5–10 years, 4 may experience a pregnancy, so it is considered to be 99.5% effective in preventing pregnancy.

The rate of pregnancy with a hormonal IUD is 1 in 500 individuals by the end of the first year. Mirena® is 99.9% effective in preventing pregnancy and Kyleena® is 99.7% effective.

What are the advantages of using an IUD as a method of contraception?

  • long acting: 5-10 years depending on type
  • reversible with rapid return to usual fertility when removed – within a month of removal
  • highly effective: the most reliable form of contraception apart from permanent sterilisation
  • relatively inexpensive – initially upfront cost. Over 5 years this is the most cost-effective form of contraception
  • Copper IUDs provide an alternative to hormonal contraception 
  • Mirena® and Kyleena® have no oestrogen and a much lower dose of progestogen compared to other hormonal options (including minipill), making them safer alternatives for individuals who can’t have oestrogen, or who do not tolerate other forms of hormonal contraception

What are the disadvantages of using an IUD as a method of contraception?

  • insertion and removal of the device can only be performed by a trained doctor
  • insertion into the uterus requires a procedure which some women may find quite uncomfortable
  • possible changes in periods/bleeding patterns: initial light bleeding or spotting while the device settles in place, expect normal or heavier periods
  • does not protect against sexually transmissible infections, so continue to use condoms for this

What are the possible risks of using an IUD?

  • Abdominal pain - Following insertion, some individuals notice abdominal cramping pain for up to a few weeks.
  • Perforation - This is a rare but serious complication where an insertion instrument or the IUD device passes through the wall of the uterus during or shortly after insertion and may then require surgery. This may occur in about 1 per 500 insertions. The risk of perforation is further increased when the IUD is inserted in an individual who is breast feeding (six times increased risk) and is within 36 weeks postpartum (three times increased risk).
  • Expulsion - Sometimes the IUD may partially or completely fall out of the uterus. It occurs in about 5 per 100 insertions and is most common in the first few months following insertion. It is important to regularly check for the threads.
  • Pelvic Inflammatory disease (PID) -  This is a rare complication of IUD insertion, most likely to occur in the first few weeks following the insertion procedure. It occurs in less than 1 per 300 insertions. PID may in some cases lead to infertility.
  • Miscarriage or ectopic pregnancy - It is very rare to become pregnant while using an IUD. If a pregnancy occurs however, there is an increased risk of a miscarriage or and ectopic pregnancy. An ectopic pregnancy is when the pregnancy develops outside of the uterus. Ectopic pregnancy is a serious condition and can lead to reduced fertility. In the rare event of a pregnancy occurring with an IUD in place, it is important to see a doctor as soon as possible if you have any reason to suspect you are pregnant, e.g. if there is a change in your usual bleeding pattern or you have unusual abdominal or pelvic pain. 

Is an IUD suitable for all women?

Most women can safely use an IUD. Your doctor will review the suitability of the method with you prior to insertion.

In assessing your suitability, consideration is given to a number of important factors:

  • current menstrual and bleeding patterns
  • unexplained vaginal bleeding (this should be investigated before using an IUD)
  • a recent history of a sexually transmitted infection or PID
  • uterine or cervical abnormalities
  • any history of breast, cervical or uterine cancer
  • pregnancy history
  • cervical screening history
  • any allergies including copper allergy
  • the timing of insertion and pain relief needs for the insertion procedure

What do I need to know about having an IUD insertion?

  • Prior to insertion, an assessment of your medical history and suitability for this method will happen. This assessment enables you to ask any questions you may have and be certain that it is the most suitable method for you.
  • Insertion of an IUD involves a procedure. Some women find insertion uncomfortable. This can be managed with the use of local anaesthetic into the cervix. If there are reasons to anticipate difficulties then a woman may choose or be advised to have a sedative or general anaesthetic.
  • The device should be inserted by a medical practitioner trained in the procedure.

What do I need to know about the ongoing use of an IUD?

You will be given details of follow up at the time of the insertion. Generally, you are asked to attend for a follow up visit after insertion and/or any time concerns exist.

You should contact your doctor if:

  • if you miss a period or you feel you may be pregnant
  • you experience pelvic pain or tenderness, fever or chills, offensive discharge or deep pain with intercourse
  • you cannot feel the string or feel the string has lengthened
  • you (or your partner) can feel the hard stem of the IUD

The IUD needs to be replaced with a new device every 5 or 10 years depending on which device is inserted. However, if you have a copper IUD inserted after the age of 40, this expiry date can often be extended and the same device left in for a longer period of time. This is because you have a lower risk of falling pregnant in your late 40s and 50s. Please discuss further with your medical practitioner.

It is important to keep a record of the date that replacement is due or remember a landmark event to arrange for replacement no later than this date. The IUD can easily be removed at any time. As fertility can return immediately after removal, it is important to consider alternative methods of contraception, before the IUD is removed, if trying to avoid pregnancy.

What are the differences between copper and hormonal IUDs?

While there are many similarities, there are some differences between copper and hormonal IUDs.

Making a choice about which IUD is most suitable for you will be based on your personal preferences, requirements, and medical issues.