Intra-uterine contraceptive device (copper)

How it works

Released copper ions are toxic to sperm and ova and provoke a sterile inflammatory endometrial reaction, preventing fertilisation and implantation.

Prescribing in practice

• Exclude existing pregnancy and current pelvic infection before insertion, and counsel that the device offers no protection against sexually transmitted infections.
• It is the most effective form of emergency contraception and can be used as ongoing contraception thereafter when fitted within the recommended window.
• Avoid in unexplained vaginal bleeding, distorted uterine cavity, current pelvic inflammatory disease, and known copper allergy or Wilson's disease.

Monitoring

Review after the first menses or a few weeks post-insertion to check threads and exclude expulsion or infection, then as clinically indicated.

Counselling the patient

• Periods may become heavier, longer or more painful, particularly in the early months.
• Check the threads periodically and seek review if you cannot feel them or feel the hard plastic of the device.
• Seek urgent care for severe pelvic pain, fever, or abnormal discharge, and remember it does not protect against STIs.

Evidence & guidelines

The copper intrauterine device is recognised by the FSRH as the most effective method of emergency contraception and a highly effective long-acting reversible contraceptive.