The video will provide you with an overview of how the intrauterine device (IUD) provides contraceptive protection.
How does the intrauterine device (IUD) work? The video will provide you with an overview of how the intrauterine device (IUD) provides contraceptive protection. Read video transcript
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How does the intrauterine device (IUD) work?

  • The copper element of the IUD is toxic to sperm and eggs
  • The IUD physically blocks sperm from reaching unfertilized eggs
  • The IUD can also affect the womb lining, and inhibits implantation of an egg if it does manage to get fertilized
  • The IUD provides contraceptive protection up to 5 or 10 years (depending on the model used)

Intrauterine device (IUD)

Also known as ‘the coil’ or copper IUD

The intrauterine device is a small device around 3 cm long that is placed into the womb by a trained healthcare professional. It is made from plastic, usually with a T-shaped frame and a copper wire, located usually in the vertical stem of the T-frame. Depending on the model, it can protect against pregnancy from up to 5 to 10 years1,2. All intrauterine devices have one or two removal threads that extend from the lower part of the T-frame to the upper part of the vagina.

Note: The intrauterine device (IUD) is also known as ‘the coil’ or copper IUD.

How the intrauterine device works

A copper intrauterine device affects reproduction at an early stage by preventing fertilization. The copper element of the intrauterine device is toxic to sperm and eggs. The intrauterine device also physically blocks sperm from reaching the egg. Furthermore, it has an effect on the lining on the womb that makes it harder for an egg to implant there2,3.

Note: The intrauterine device (IUD) is also known as ‘the coil’ or copper IUD.

Before placement of the intrauterine device

Before the intrauterine device is placed in your womb, your healthcare professional will perform a series of health checks that may include a blood pressure check, a breast examination, a cervical (Pap) smear, and a pelvic examination to check the position and size of your uterus2. If necessary, he/she can also test to rule out pregnancy or sexually transmitted infections.

Note: The intrauterine device (IUD) is also known as ‘the coil’ or copper IUD.

Placement of the intrauterine device

The intrauterine device is always placed in your womb by a healthcare professional trained to place such a device. It is a routine procedure that normally takes just a few minutes following your pelvic examination.

Placement of an intrauterine device (IUD).Once your cervix has been cleaned with an antiseptic solution, the depth of the uterine cavity is measured and the intrauterine device is placed into the womb via a thin, flexible plastic tube.

Most women find the placement procedure only causes minor discomfort whereas others find it more uncomfortable. You can discuss with your healthcare professional in advance whether some measure of pain management is appropriate for you.

The intrauterine device can be placed at any time during your period, but to minimize the risk of an undetected pregnancy the best time to do it is within seven days from the onset of the menstrual bleeding2. The device can also be placed immediately after abortion, as long as there are no genital infections2. If you have given birth, the intrauterine device should not be placed until at least 6 weeks after having given birth2. A copper-releasing intrauterine device can be used within 5 days of unprotected intercourse as an emergency contraceptive4.

Note: The intrauterine device (IUD) is also known as ‘the coil’ or copper IUD.

Check-ups after placement of the intrauterine device

You should have an initial check-up at 4 - 12 weeks after placement2. Subsequent check-ups should be at least once a year2. You should contact your healthcare professional if you experience any of the following2:

  • your periods have changed from normal and cause discomfort
  • your period is delayed (you suspect pregnancy)
  • you experience persistent abdominal pain (possibly together with fever) or unusual vaginal discharge
  • you or your partner feel pain or discomfort during intercourse
  • you no longer feel the threads in your vagina
  • the intrauterine device has moved and you can feel its lower tip


After 5 (or 10) years, depending on the model, the intrauterine device should be removed2.

Note: The intrauterine device (IUD) is also known as ‘the coil’ or copper IUD.

Removal of the intrauterine device

Your intrauterine device can be removed very easily and usually painlessly by a healthcare professional by pulling on the removal threads5. Fertility returns to normal immediately after removal3. To avoid pregnancy, removal should be carried out during your period. Sexual intercourse in the week before removal, during the middle of your cycle, can lead to pregnancy2. So, you should use an alternative form of contraceptive for a few days before, and after removal of the device2.

Note: The intrauterine device (IUD) is also known as ‘the coil’ or copper IUD.

Effectiveness of the intrauterine device (in preventing pregnancy)

A copper intrauterine device will provide you with effective contraception for up to 5 and 10 years1,2, depending on the model used. Pregnancy rates with this type of contraceptive are very low. Between 6 (perfect use) and 8 (typical use) women per thousand become accidentally pregnant during the first year of using the intrauterine device6. By using the intrauterine device, which is permanently in place, no pregnancies occur due to problems remembering to use a contraceptive.

Women who rely on their partner using condoms can typically experience a pregnancy rate as high as 180 per thousand women per year (only 20 per thousand if used perfectly)6. As with other long-acting reversible contraceptives (LARC), the intrauterine device offers the advantage of a contraceptive that you don’t have to think about and which doesn’t stop the spontaneity of sex.

Note: The intrauterine device (IUD) is also known as ‘the coil’ or copper IUD.

Return to fertility after using the intrauterine device

There is no effect on fertility, and after your intrauterine device is removed, your fertility returns to “normal” (as before placement)3.

Note: The intrauterine device (IUD) is also known as ‘the coil’ or copper IUD.

Using the intrauterine device while breastfeeding

The intrauterine device can be placed as early as six weeks after having given birth. It is then safe to breastfeed, as no negative effects on infant development or growth have been observed2.

Note: The intrauterine device (IUD) is also known as ‘the coil’ or copper IUD.

Side-effects & the intrauterine device

Changes to your periods


There may well be changes to your periods following placement of the intrauterine device. The number of bleeding and spotting (a small amount of blood loss) days may increase during the first few months and bleeding may be heavier2. The most common reasons for discontinuation of IUD use are unacceptable vaginal bleeding and pain3.


Other side-effects include:


  • abdominal pain (for a short time after placement of the intrauterine device)
  • allergic skin reactions
  • anemia (a reduction of the amount of iron in the blood) due to increased menstrual blood loss


For further information on other areas of concern go to the side effects: intrauterine device (IUD) page.

Note: The intrauterine device (IUD) is also known as ‘the coil’ or copper IUD.

When should you not use the intrauterine device?


There are a number of medical conditions which may make it unsuitable for you to have the intrauterine device put in place if you have2:

  • a known or suspected pregnancy
  • current or recurrent pelvic inflammatory disease; lower genital tract infection
  • infection of the womb after having given birth or after abortion during the past 3 months
  • untreated cervicitis (inflammation of the neck of the womb)
  • cancer of the cervix or womb
  • untreated cervical dysplasia
  • undiagnosed abnormal womb bleeding
  • abnormality of the cervix or womb including fibroids if they distort the womb cavity
  • copper allergy
  • Wilson's disease (a disturbance of the body’s copper balance)
  • disturbances in blood clotting
  • conditions associated with increased susceptibility to infections


As intrauterine devices may increase menstrual blood loss and period pain (dysmenorrhea), they may not be an appropriate first choice method for women who suffer from excessive menstrual bleeding, anemia (a reduction in the amount of iron in the blood), dysmenorrhea (painful menstruation), or are on anticoagulants (drugs used to limit the normal clotting processes of the blood). If these conditions develop while you are using the intrauterine device, removal should be considered2.

Use with caution

Copper intrauterine devices should be used with caution if you have congenital heart disease or valvular heart disease at risk of infective endocarditis. In such cases you should be given antibiotics when the device is placed or removed2.

Your contraceptive choices

FAILURE RATE

FAILURE RATE

FAILURE RATE

FAILURE RATE

2| 1,000WOMEN(number of pregnancies after one year of use)
6-8| 1,000WOMEN(number of pregnancies after one year of use)
2-60| 1,000WOMEN(number of pregnancies after one year of use)
< 1| 1,000WOMEN(number of pregnancies after one year of use)

ADMINISTRATION

ADMINISTRATION

ADMINISTRATION

ADMINISTRATION

Placement in womb
Placement in womb
Injection in arm or buttock
Placement under the skin of arm

LENGTH OF PROTECTION

LENGTH OF PROTECTION

LENGTH OF PROTECTION

LENGTH OF PROTECTION

Up to 5 years
Up to 5 to 10 years, depending on model
12 weeks
Up to 3 years

RETURN TO FERTILITY

RETURN TO FERTILITY

RETURN TO FERTILITY

RETURN TO FERTILITY

No delay
No delay
Possible delay of up to 1 year following treatment cessation
No delay

MENSTRUAL BLEEDING

MENSTRUAL BLEEDING

MENSTRUAL BLEEDING

MENSTRUAL BLEEDING

  • Initially periods may be lighter or heavier, longer or shorter or absent.
  • Infrequent or absent periods likely after several months.
  • Bleeding and spotting days may increase in first few months.
  • Bleeding may be heavier.
  • Irregular and possibly lengthy bleeding or spotting or no bleeding at all.
  • Periods may become more or less frequent, continuous or absent.
  • May reduce or increase in intensity or duration.

BODY WEIGHT

BODY WEIGHT

BODY WEIGHT

BODY WEIGHT

No effect
No effect
May cause weight gain of 2.3 – 3.6 kg in the first year
No effect

USE DURING BREASTFEEDING

USE DURING BREASTFEEDING

USE DURING BREASTFEEDING

USE DURING BREASTFEEDING

  • Yes
  • 6 weeks after birth
  • Yes
  • 6 weeks after birth
  • Yes
  • 6 weeks after birth
  • Yes
  • 4 weeks after birth

HEAVY PERIOD TREATMENT

HEAVY PERIOD TREATMENT

HEAVY PERIOD TREATMENT

HEAVY PERIOD TREATMENT

Yes
No
No
No

USE IN ESTROGEN THERAPY

USE IN ESTROGEN THERAPY

USE IN ESTROGEN THERAPY

USE IN ESTROGEN THERAPY

Yes – Recommended for use in conjunction with estrogen replacement therapy
No – Not recommended for use in conjunction with estrogen replacement therapy
No – Not recommended for use in conjunction with estrogen replacement therapy
No – Not recommended for use in conjunction with estrogen replacement therapy