Intro, efficacy, duration of use, choice of device and assessing suitability

DGRefHelp - NHS Dumfries & Galloway
NHS Dumfries and Galloway

Introduction

Cu-IUDs are non-hormonal and vary in size and shape Types of Cu-IUD  They consist of copper and plastic and may contain barium for radio-opacity. Some types contain a core of silver or other inert metal, which helps to maintain the integrity of the wire. 

In addition to regular contraception, the Cu-IUD can be used for emergency contraception (EC), if inserted within 5 days after the first episode of unprotected sexual intercourse (UPSI) that cycle, or within 5 days of the earliest expected date of ovulation. (see Emergency Contraception Protocol).

A Cu-IUD is effective immediately following insertion.

The main mode of action of a Cu-IUD is inhibition of fertilisation through the effect of copper on the ovum and sperm, but copper in the cervical mucus also inhibits the passage of sperm into the upper reproductive tract.
The Cu-IUD also causes an inflammatory response within the endometrium, which could impair implantation.

Efficacy, duration of action and choice of device

The failure rate of Cu-IUD use is very low.

  • Cumulative pregnancy rates for Cu-IUDs with 380mm2 copper are between 0.1 and 1% after the first year of use.
  • Pregnancy rates have been found to be lowest for the T-shaped devices which have a copper surface area of 380 mm2 with copper bracelets on the arms in addition to the coiled copper wire on the stem.
  • Cu-IUDs with longest duration of use should ideally be used as they reduce the risk of infection, perforation and expulsion associated with reinsertion see Types of Cu-IUD .
  • For individual clients width of insertion tube and length of device may also have to be considered (see Types of Cu-IUD
  • The LNG-IUD maybe superior in terms of efficacy, although the failure rate is very low for both Cu-IUD and LNG-IUD.
  • The contraceptive effectiveness of Cu-IUD is not affected by use of enzyme-inducing drugs or weight/BMI
  • The intrauterine ball is not available in the UK at the time of guideline publication

Cu-IUDs can be used for contraception for 5 or 10 years (device dependent). If a Cu-IUD with a copper surface area ≥300 mm2 is inserted when the individual is ≥40 years old, the FSRH supports extended use of the device, and the Cu-IUD can be used for contraception until menopause. It can be removed 1 year after the final menstrual period if this occurs after age 50 years.

 

Assessing Suitability

Few medical conditions contraindicate use of IUC (see UK Medical Eligibility Criteria for Contraceptive Use (UKMEC)

Investigations are not routinely required prior to insertion.

Most Cu-IUD insertions are straightforward and can be undertaken in primary care /community settings. There will be additional considerations for some individuals, for example, pre-insertion investigations, alterations to current medication dosage/timing, discussion with the individual’s usual care provider or a requirement to insert the Cu-IUD in a specialist setting.


The use of the Cu-IUD is contraindicated if there is a known or suspected allergy or hypersensitivity to any of the components of the device.

Editorial Information

Last reviewed: 25/08/2023

Next review date: 01/10/2025

Author(s): West of Scotland Managed Clinical Network in Sexual Health Clinical Guidelines Group .

Version: 10.1

Approved By: West of Scotland Managed Clinical Network in Sexual Health