Intrauterine Devices

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What is an Intrauterine Device (IUD)?

An IUD is a small, flexible device which is inserted into the uterus (womb) by a health professional to prevent pregnancy. IUDs have fine threads attached to their lower end so that when they are fitted, the threads extend through the cervix into the vagina.

IUDs come in two major types:

Copper IUDs The copper IUD is a plastic frame with copper sleeves or wire around it. There are two types of copper IUDs currently available in Australia.

Hormonal IUDs The hormonal IUD is a plastic frame with a core which slowly releases a progestogen hormone called levonorgestrel. There is one type of hormonal IUD currently available. Sometimes called an intrauterine system (IUS), this is commonly known by the brand name Mirena®.

Once inserted, IUDs cannot usually be felt by the woman or her partner.

How do they work?

Copper IUDs primarily work by affecting sperm movement, stopping them from moving through the uterus. They also cause changes to the lining of the uterus (endometrium) which, in the rare instance of an egg being fertilised, prevent the egg from attaching to the endometrium. Copper IUDs are sometimes used as a very effective form of emergency contraception up to the fifth day after unprotected sex.

Hormonal IUDs work by releasing a progestogen hormone at a steady rate, making the lining of the uterus thin and unsuitable for implantation of a fertilised egg. It has an additional effect of making the cervix produce thick mucus that prevents sperm from entering the uterus and moving towards the egg. In some women, hormonal IUDs also stop the ovaries releasing an egg (ovulation) altogether.

How effective are they?

IUDs are more than 99% effective at preventing pregnancy. Copper IUDs are effective for five to ten years, depending on the type. Copper IUDs inserted in women over the age of 40 can be left until after menopause. Mirena® provides effective contraception for five years.

Who can use an IUD?

IUDs are effective, safe and reliable long-term methods of contraception for many women. Your health professional will take a detailed medical history and pelvic examination to ensure that an IUD is suitable for you.

An IUD may not be suitable for women who have:

more than one sexual partner, or a partner who has other partners
uterine or cervical abnormalities

Copper IUDs may not be suitable for women with very heavy, painful or prolonged periods, or iron deficiency anaemia. Hormonal IUDs may not be suitable for women with a history of breast cancer.

An IUD is not suitable for women who have:

a current pelvic infection or recent history of Pelvic Inflammatory Disease
a high risk of acquiring a sexually transmissible infection (STI)
unexplained vaginal bleeding (for example, bleeding between periods or after sex)
current cancer of the cervix or uterus

Hormonal IUDs may be particularly suitable for women who:

have heavy or painful menstrual bleeding (women using Mirena® often have lighter, less painful periods, or none at all)

What are some of the advantages of IUDs?

IUDs:

are very effective and safe forms of long-term contraception
are relatively inexpensive, considering how long they last
are a suitable method of contraception for some women who are unable to take oestrogen
can be removed at any time, and fertility returns quickly
have very small or no metabolic effects (eg on cholesterol levels and blood clotting)
are not affected by other medicines

What are some of the disadvantages of IUDs?

Periods may be heavier, longer and more painful with a copper IUD. This may improve after the first few months.

After having Mirena® inserted women may experience frequent (but usually light) bleeding or spotting in the first few months. Some also experience hormonal side effects, such as mood changes or breast tenderness, but these usually improve with time.

IUDs do not protect against STIs.

How are IUDs inserted?

The insertion of an IUD does not usually require a general anaesthetic or sedation. The health professional will do an internal examination to determine the size and position of the uterus. A speculum is put into the vagina so that the cervix can be seen. After measuring the length of the uterus with a small rod, the device is inserted.

Many women have cramping similar to period pain and sometimes feel faint. The level of discomfort felt can vary greatly between women - discuss this and pain relief methods with the health professional. Women who haven't given birth may find IUD insertion more uncomfortable than those who have had children.

When can an IUD be inserted?

IUDs can be inserted any time that pregnancy can confidently be excluded. Because a copper IUD works as an emergency contraceptive, it can also be put in during the first 12 days of the menstrual cycle, or up to five days after the first incidence of unprotected sex in a cycle.

Mirena® can be inserted between day 1 (first day of menstrual bleeding) to day 7 of the menstrual cycle, or at other times provided there is no possibility of pregnancy in the current cycle.

What to do after your IUD is inserted

FPWA recommends that women don't put anything into their vagina for 48 hours after the insertion of an IUD to reduce the risk of infection. This means no tampons (use pads), no intercourse, no swimming and no baths (shower instead) for two days after insertion.

You will need to visit a health professional for a check-up a few weeks after the insertion, and then once every one or two years. This can coincide with your Pap smear.

In a small percentage of women the IUD can be expelled by the uterus. This most commonly happens in the first few months after insertion.

Learn to check the threads of your IUD, and do so every month. This tells you that it is still in place and has not been expelled by your uterus, perhaps during a period. Most pregnancies that occur in women using IUDs are due to unnoticed expulsion.

To feel the threads place two fingers deep in your vagina and feel for the firm knob (like the end of your nose) that is your cervix. The threads should come out of the cervix and lie next to it. Many women find this convenient to do in the shower. If you cannot feel the threads (and they can be hard to find), go back to the health professional for a check-up, and use other contraception until then.

Possible but rare risks

Perforation
Rarely the IUD may be pushed through the wall of the uterus and then require removal by surgery under general anaesthetic.

Pelvic infection
The risk of pelvic infection is highest in the first three weeks following insertion. FPWA recommends screening for genital tract infections prior to the insertion of an IUD to reduce the risk of these infections being passed into the uterus.

Ectopic pregnancy and miscarriage
Very few women become pregnant while using an IUD. If a pregnancy does occur with an IUD in place there is a small chance of ectopic pregnancy (a pregnancy that develops outside the uterus, usually in a fallopian tube). This is a serious condition that needs urgent medical attention.

If a pregnancy occurs in the uterus there is risk of miscarriage. If the IUD is left in place during pregnancy, there is an increased risk of miscarriage in later stages of pregnancy or premature birth.

If you have an IUD and think you may be pregnant, do a pregnancy test. If the test is positive, see a doctor as soon as possible.

Removal

Never attempt this yourself. Removal should only be undertaken by a trained health professional who will remove the IUD by pulling gently on the threads. Mild cramping and some bleeding may be experienced when the device is removed.

It is important to consider future contraceptive needs before having your IUD removed, as its contraceptive effects will cease upon removal. A health professional can discuss this with you further.

Practising safe sex reduces the risk of contracting HIV and other sexually transmissible infections (STIs).

Page last updated Mon, 08 Aug 2011 14:14