Contraception - intrauterine devices (IUD)

An intrauterine device (IUD) is a small contraceptive device that is placed inside the uterus (womb) to prevent pregnancy. There are two types: the copper IUD and the hormonal IUD (sold under brand names such as Mirena™ and Kyleena™). Kyleena™ is a lower-dose version of Mirena™.

IUDs are known as long-acting reversible contraception, or LARC, because they work over a number of years. Both types are more than 99 per cent effective at preventing pregnancy. The copper IUD can stay in place for up to 10 years, and the hormonal IUDs for about 5 years, but both can easily be removed sooner if needed.

How each type works#

• Copper IUD: a small, T-shaped plastic and copper device. It continuously releases a small amount of copper into the uterus. It contains no hormones, which makes it a choice for people who do not want to use hormonal contraception. It can also be used for emergency contraception, instead of the emergency contraceptive pill (“morning-after pill”), if fitted within 5 days of unprotected sex.
• Hormonal IUD: a small, T-shaped plastic device that slowly releases a hormone (progestogen) into the uterus. Progestogen is similar to a hormone produced by the ovaries.

Having an IUD inserted#

A doctor or nurse can give you a prescription, and you may collect the IUD from a pharmacy; sometimes a copper IUD can be supplied by the clinic doing the insertion. The IUD is then inserted into your uterus by a trained doctor or nurse.

The IUD has a fine nylon thread attached to it that passes out through the cervix (the opening to the uterus). The thread sits high in the vagina, so it cannot be seen, but you can feel high up inside the vagina to check the thread is there and know the IUD is still in place.

It is a good idea to record the date the IUD was inserted, so you know when it needs to be removed or replaced before it expires (after 5 or 10 years, depending on the type).

Costs vary depending on the type of device, the provider, and whether you attend a public or private service. Ask your provider what to expect, including any prescription, device and insertion costs.

Advantages of IUDs#

• They are more than 99 per cent effective at preventing pregnancy
• They last a long time: about 5 years for the hormonal IUD and up to 10 years for the copper IUD
• Once in place, you do not need to do anything except check the thread each month after your period
• No medications stop an IUD from working
• They are safe to use while breastfeeding
• They offer another option if you have difficulty using oestrogen-based methods, such as the combined pill or the vaginal ring
• The copper IUD is a very effective method of emergency contraception

With the hormonal IUD, many users have little or no bleeding, and periods may be less painful. The copper IUD contains no hormones and is suitable for people who prefer to avoid hormonal contraception.

Possible side effects#

When first inserted, some people have period-type cramping that usually settles after a few days. Other possible effects include:

• With the hormonal IUD: spotting or frequent bleeding is common in the first 3 to 6 months. By 6 months, around 90 to 95 per cent of users have a light, regular period or no bleeding at all, which is not harmful. Some people notice tender breasts, headaches, skin changes or mood changes. These nearly always settle with time. The hormonal IUD has not been shown to cause weight gain.
• With the copper IUD: periods may be heavier, and there may be spotting or frequent bleeding in the first few months. This nearly always settles with time, after which your regular bleeding pattern returns.

Sometimes an IUD can come out on its own. This is more common in the first 3 months after insertion. It is worth checking that the device has not moved out of position. An IUD can be removed at any time by an appropriately trained doctor or nurse, and your usual fertility returns once it is out.

Potential health risks#

• In about 1 in 500 people, a small hole may be made in the wall of the uterus during insertion. The IUD can move through this hole and sit in the wrong place. If this happens, it needs to be removed, sometimes using keyhole surgery (a laparoscopy).
• In about 1 in 300 people, an infection may occur when the IUD is first inserted. This can usually be treated successfully with antibiotics.

It is very unlikely to become pregnant while using an IUD. If you do become pregnant with an IUD in place, there is a higher chance of an ectopic pregnancy (where the pregnancy settles in the fallopian tubes rather than the uterus). This needs urgent medical attention.

If you become pregnant while using an IUD, see a doctor or nurse as soon as possible. The device should be removed and an ectopic pregnancy ruled out. If the IUD is removed, you can choose to continue or to end the pregnancy. If it is not removed and the pregnancy continues, there is a higher risk of miscarriage or of delivering the baby early.

When an IUD may not be suitable#

An IUD might not be a good option for you if you have:

• A uterus that is not the usual shape
• A current pelvic infection

The hormonal IUD might not suit you if you have been treated for breast cancer or have severe liver disease. The copper IUD might not suit you if you have heavy periods, low iron levels or endometriosis.

IUDs after birth and fertility#

An IUD can be inserted within 2 days after giving birth. If it is not inserted soon after birth, you usually need to wait at least 4 weeks. IUDs are safe to use while breastfeeding. If you later decide you want to become pregnant, the IUD can be removed at any time and your fertility returns.

IUDs and STIs#

Neither type of IUD protects you from sexually transmissible infections (STIs). It is important to practise safer sex as well as to prevent unintended pregnancy. The best way to lower the risk of STIs is to use barrier methods, such as external or internal condoms, including for oral, vaginal and anal sex with new partners. Condoms can be used together with an IUD.

Choosing the right method#

When choosing the contraceptive method that best suits you, it helps to talk to a doctor or nurse about your options, as different methods may suit you at different times in your life. They can explain:

• How each method meets your current and future needs
• How well each method works, and its benefits and risks
• The possible side effects
• How easy each method is to use
• How much each method costs

Other methods include the contraceptive implant or injection, the vaginal ring and the combined oral contraceptive pill.

Key points#

• IUDs are long-acting reversible contraception (LARC) and work over a number of years
• The thread sits high in the vagina and cannot be seen, but you can feel it to check the IUD is in place
• An IUD coming out is more common in the first 3 months after insertion
• Spotting or frequent bleeding is common in the first 3 to 6 months
• The hormonal IUD has not been shown to cause weight gain

Where to get help#