An intrauterine device (IUD) is a small T-shaped plastic and copper device that’s inserted into your womb by a specially trained health professional. Find out how it works, and about the side effects and benefits.
A woman can get pregnant if a man’s sperm reaches one of her eggs (ova). Contraception tries to stop this happening by keeping the egg and sperm apart or by stopping egg production. One method of contraception is the intrauterine device, or IUD.
There are various types and sizes of IUD (sometimes called a coil). Depending on the type, an IUD can last from three to 10 years.
The IUD is a long-acting reversible contraceptive (LARC) method. This means that once it's in place, you don't have to think about contraception every day or each time you have sex.
You can use an IUD whether or not you've had children.
How does an IUD work?
The IUD works by preventing sperm from surviving in the cervix, womb or fallopian tubes. It may also prevent a fertilised egg from implanting in the womb.  Â
How effective is an IUD?Â
IUDs are more than 99% effective. This means that fewer than one in every 100 women who use an IUD will become pregnant in one year.
Added benefits of an IUD?
- An IUD is effective as soon as it's put in.
- It can be removed at any time by a specially trained health professional.
- Once the IUD is removed, you'll quickly return to normal levels of fertility.
What else should IÂ know?
Changes to your periods are common in the first three to six months after an IUD is put in, but they're likely to settle down after this. It can make your periods heavier, longer or more painful, and you might get spotting or bleeding between periods. Heavy bleeding can be treated, so talk to your doctor or nurse about this.
- There's a very small chance of infection within 20 days of the IUD being fitted.
- There's a risk that your body may spontaneously expel it.
- If you get pregnant, there's an increased risk of having an ectopic pregnancy (when the egg implants outside the womb, e.g. in the fallopian tube). But because pregnancy is very unlikely, the overall risk of ectopic pregnancy is lower than in women who don't use contraception.
- Having the IUD put in can be uncomfortable: you may want to use pain-relieving drugs or a local anaesthetic. Ask the doctor or nurse about this.
- An IUD may not be suitable for you if you've had previous pelvic infections.
By using condoms as well as the IUD, you'll help to protect yourself against sexually transmitted infections (STIs).
Further information
Having an IUD fitted
Which contraceptive method suits me?
Visiting an STI clinic
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