FFinalistSouthampton · 2027
Obstetrics & gynaecology
AKT · Obstetrics & gynaecology/Contraceptionlow yield

Copper intrauterine device (Cu-IUD)

Copper coil — non-hormonal; toxic to sperm/ova

Overview

A non-hormonal intrauterine device (LARC, 5–10 years) — copper is toxic to sperm and ova and inhibits implantation. The only hormone-free LARC, and the MOST EFFECTIVE emergency contraception. The trade-off is heavier, more painful periods.

Recognise

  • Non-hormonal LARC, effective 5–10 years; works immediately
  • Periods become HEAVIER and more painful (opposite of the LNG-IUS)
  • The most effective emergency contraception — within 120h of UPSI or 5 days of expected ovulation
  • Small risk of perforation and expulsion; PID risk in the first 20 days

Red flags

  • Undiagnosed abnormal bleeding, current pelvic infection, or known pregnancy before fitting; Wilson disease (copper)

Differentials & how to tell them apart

Levonorgestrel IUShormonal coil — LIGHTENS periods and treats HMB; the copper coil worsens bleeding
Ulipristal/levonorgestrel (oral EC)oral emergency options delay ovulation only — less effective than the copper coil and useless post-ovulation

Investigations

STI risk assessment, exclude pregnancy and undiagnosed bleeding before fitting.

Management

Copper IUD — hormone-free LARC and the most effective emergency contraception

  1. 1Offer when hormones are unwanted/contraindicated, or as the most effective emergency contraception (within 5 days of UPSI or expected ovulation).Gate: For emergency contraception the copper IUD beats oral methods and works even AFTER ovulation has occurred — offer it first if within the window
  2. 2Heavy/painful periods after fitting → reassure or consider switching to the LNG-IUS.
Copper IUD — non-hormonal; also first-line emergency contraception

Key points

If a woman presents for emergency contraception within the window, the copper coil is the most effective option and also gives ongoing contraception.

Monitor & prognosis

Threads check; bleeding pattern; replace at licensed interval.

Immediately reversible; fertility returns at once.

Source: FSRH UKMEC 2016; FSRH emergency contraception guidance