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Intrauterine Devices

Intrauterine Devices (IUDs) are also known as Intrauterine Contraceptive Devices. Intrauterine devices include copper IUDs and hormone releasing IUDs.

What is an IUD?

An IUD is a small device which is inserted into your uterus (womb) by a doctor to prevent pregnancy. IUDs come in two major types. Copper IUDs are made of plastic and copper wire.  The Multiload 375 and the Copper T 380 are the main brands used in Australia.  The hormone releasing IUD is also made of plastic, but contains a progestogen hormone called levonorgestrel. This is sometimes called an intrauterine system (IUS) and is commonly known by its brand name Mirena.

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. The IUD is sometimes used as a very effective form of emergency contraception up to the fifth day after unprotected intercourse, though this is not common in Australia.

Mirena works by releasing a progestogen hormone at a steady rate, making the mucus at the cervix thick so sperm can’t move towards the egg.

How effective are they?

IUDs are more than 99% effective at preventing pregnancy.  Copper IUDs are effective for eight 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 doctor will take a detailed medical history to ensure that an IUD is suitable for you.

An IUD is not suitable for a woman who:

  • has a pelvic infection
  • is or could be pregnant
  • has abnormal vaginal bleeding for which the cause has not been found
  • has a high risk of acquiring a sexually transmissible infection (STI).

Copper IUDs are also not suitable for women who have very heavy, painful or prolonged periods, or who have iron deficiency anaemia.

An IUD may not be suitable for a woman who has:

  • never had a child
  • more than one sexual partner, or a partner who has other partners
  • a bleeding disorder
  • valvular heart disease
  • a uterine abnormality such as fibroids.

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 between the first day of your period and ovulation.  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.

FPWA recommends that women be screened for genital infections prior to the insertion of an IUD. If a Pap smear is due, this can be done at the same time.

How is it done?

The insertion of an IUD does not require a general anaesthetic. The doctor or nurse will do an internal examination to determine the size and position of your uterus. A speculum is put into your vagina so that the doctor can see the cervix. After measuring the length of the uterus with a small metal rod, the device is inserted. Many women have cramping similar to period pain, but this usually wears off very quickly.  It is usually recommended that women take two Nurofen, Naprogesic or similar pain relievers an hour before their insertion appointment.

Some women may feel faint but will recover quickly. Women who have given birth may find IUD insertion less uncomfortable than those who have not had children

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 doctor for a check-up after your next period, and then once every 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 month after insertion. Expulsion is more common in women who have never had children.

Learn to check the thread of your IUD. 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 thread place two fingers deep in your vagina and feel for the firm knob (like the end of your nose) that is your cervix. The thread should come out of the cervix and lie next to it.

You should check the thread once a month after your period before you rely on it for contraception. Many women find this convenient to do in the shower. If you cannot feel the thread (and it can be hard to find), go back to the clinic for a check up, and use other contraception until then.

Advantages

IUDs:

  • are very effective and safe forms of long-term contraception
  • are cheap, considering how long they last
  • do not usually interfere with your normal hormonal cycle 
  • are a suitable method of contraception for some women who are unable to take the Pill 
  • can be removed at any time, and fertility returns quickly
  • have very small or no metabolic effects (eg on cholesterol levels and blood clotting).

Unlike copper IUDs, Mirena is suitable for women who have heavy menstrual bleeding.  Women using Mirena often have frequent spotting for a few months, then have lighter, less painful periods, or none at all.

Aside from its use as a contraceptive device, Mirena can also be used as an alternative to surgical or oral hormonal treatments for women with heavy menstrual bleeding, and by menopausal women taking oestrogen who can not tolerate other forms of progestogen.

Disadvantages

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

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

Possible risks

Pelvic infection
The risk of pelvic infection is highest in the first three weeks following insertion. FPWA recommends screening for vaginal and cervical infections prior to insertion to reduce the risk of these infections being passed into the uterus. After this there is no difference in the risk of pelvic infection between IUD users and other women. A pelvic infection may cause damage to the fallopian tubes, which can lead to infertility. It can also cause chronic pelvic pain.

Possible symptoms of infection include:

  • pain or tenderness in the lower abdomen
  • unusual bleeding from the vagina
  • fever or chills
  • discharge from the vagina
  • deep pain during intercourse
  • a burning sensation when passing urine.

Pregnancy with an IUD in place
Modern IUDs are now more than 99% effective. In other words, less than 1 out of every 100 women using them for a year will get pregnant. If you have an IUD and think you may be pregnant, do a pregnancy test.  If the test is positive, see your doctor immediately to get it removed. If the device is left in position during pregnancy, there is a higher risk of miscarriage later in the pregnancy. Of those rare pregnancies that may occur with an IUD, a slightly greater proportion may be an ectopic pregnancy (pregnancy in a fallopian tube). For this reason if you think you might be pregnant it is very important to see a doctor.

Perforation
In a small number of cases (one per thousand insertions), the IUD may be pushed through the wall of the uterus and then require removal by an operation. This risk is reduced if the doctor fitting the IUD is very skilled in insertion.

Short Wave Diathermy Treatment

Women with copper IUDs should not have short wave diathermy treatment to the abdomen or lower back. Diathermy is used by physiotherapists in the treatment of some kinds of muscular pain. IUDs do not cause problems with other treatment such as ultrasound or massage.  If in doubt, tell the treating doctor or physiotherapist that you have an IUD in place.

Removal

Never attempt this yourself. A doctor will remove the IUD at your request. Cramping and some bleeding may be experienced when the device is removed.

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

Page last updated Thu, 03 Apr 2008 11:59