IUD

The IUD or ‘intrauterine device’ is a small plastic and copper-containing device that is fitted through the cervix into the uterus.

The IUD works either by stopping sperm meeting an egg or by creating a hostile environment in the uterine lining, which prevents the early fertilised egg from implanting.

An alternative version of the IUD is called the IUS (intrauterine system). The IUS contains a progestin hormone which, rather like a progestin in a pill or injection, has additional contraceptive properties. IUS tend to be much more expensive than an IUD.

Inserting an IUD (or IUS) is a simple procedure that takes about 5 minutes that requires training.

Depending on the device, it needs to be replaced every 5-10 years.

The IUD works as soon as it is put in. Consequentially an IUD can be used not just for routine contraception but also as emergency contraception, as long as it is inserted within 5 days of unprotected sex.

Common products

• TCu-380A (an IUD, also called “copper T”, “the coil” or Paraguard, Multiload?), which lasts 10 years
• Levonorgestrel-releasing intrauterine system (an IUS or LNG-IUS, also called Mirena), which last 5 years

How effective is the IUD at preventing a pregnancy?

The IUD is excellent at preventing a pregnancy, with less than a 1% failure rate per year (6-8 pregnancies per 1,000 women). The IUS is even more effective (2 pregnancies per 1,000 women).

Over a 10 year period the TCu-380A has a failure rate of 2%.

What are other good things about the IUD?

The IUD is suitable for most women. Once inserted the woman does not need to think about it until it needs replacing. It works as soon as it is put in and stops working as soon as it is taken out.

Some reasons that a woman might not be suitable for an IUD include the presence of abnormal vaginal bleeding; a recent or current history of infection following childbirth or abortion, or likelihood of a current sexually transmitted disease; genital cancer or TB; or untreated AIDS.

The IUD itself rarely causes an infection.

What women say they like about IUDs

According to the WHO, some women prefer an IUD because: it works very well at preventing a pregnancy; it last a long time; and they do not have to think about taking something every day as a contraceptive. Many women also like that they continue having a regular period with an IUD (though not with an IUS), which helps to allay fears about the effect on fertility.

Some women like the IUS because it can help to reduce pain and bleeding for women with heavy periods.

What aspects of the IUD might women not like/ should they be aware of?

An IUD can cause side effects.

The most common side effect is a change in bleeding patterns. Women with the IUD often report heavier periods, while those with the IUS frequently report lighter or no periods.

A serious but very rare side effect is puncturing of the uterus during insertion, when the IUD itself may become embedded in the uterine wall. A trained provider should measure the uterus before insertion to avoid this situation.

Once inserted the IUD does not move around the body and stays within the uterus.

Each coil contains threads or very fine string at its end. The threads hang through the cervix and into the vagina and can be felt by self-examination or by direct inspection in a clinic. The presence of the threads allows the patient and provider to know that the IUD is still inside the uterus.

Unlike condoms, the IUD does not protect against sexually transmitted infections.