Copper T Intrauterine Device (IUD): Comprehensive Overview
What is the Copper T IUD?
The Copper T380-A (ParaGard) is a T-shaped intrauterine device containing 380 mm² of copper that provides highly effective, long-acting reversible contraception for 10 years with a failure rate of less than 1%. 1
The device is used by over 150 million women worldwide, making it the most widely used reversible contraceptive method globally. 2
Types of Copper IUDs
Available Copper IUDs
- TCu380A (Copper T380-A, ParaGard): The most effective copper IUD, approved for 10 years of use in the United States 1
- TCu380S: Slightly more effective than TCu380A after the first year, though associated with higher expulsion rates 3
- MLCu375, MLCu250, TCu220, TCu200, NovaT: Older generation devices that are less effective than TCu380A 4, 3
TCu380A and TCu380S are superior to all other copper IUDs in preventing pregnancy. 3 TCu380A demonstrated significantly better efficacy than MLCu375 (rate difference 1.70% after 4 years), MLCu250, TCu220, and TCu200. 4
Mechanism of Action
The copper IUD prevents pregnancy primarily by preventing fertilization, not by preventing implantation. 5
Specific Mechanisms:
- Spermicidal effect: Copper ions create a toxic environment for sperm, inhibiting sperm motility and viability 6
- Inflammatory response: Creates a sterile inflammatory reaction in the endometrium that is toxic to sperm and ova 5
- Cervical mucus alteration: Thickens cervical mucus, creating a barrier to sperm penetration 6
- All mechanisms occur before fertilization, making this a true contraceptive rather than an abortifacient 7
Method of Insertion
Timing of Insertion
- Immediate effectiveness: No backup contraception is required after insertion, as the device is effective immediately 8, 9
- Can be inserted at any time during the menstrual cycle if pregnancy can be reasonably excluded 1
- Postpartum insertion: Safe at ≥4 weeks after delivery, or can be inserted immediately postpartum (though with higher expulsion rates) 1
Insertion Procedure Considerations
- STI screening: Can be performed on the day of insertion; treatment can be provided afterward without device removal if needed 1, 9
- Pain at insertion: Less than 1.5% of women experience significant problems such as difficult insertion, pain, bleeding, or syncope 6
- Perforation risk: Occurs in 0.6 to 16 cases per 1000 insertions; risk is higher when inserted less than 4-6 weeks postpartum or post-abortion 6
- Nulliparous women: Experience more pain during insertion but are otherwise appropriate candidates 6, 3
Post-Insertion Monitoring
- Infection risk window: The risk of pelvic infection is confined to the first 20-21 days after insertion 1, 2
- Expulsion rates: Occur in 5-10% of cases within 5 years, with higher rates in younger nulliparous women 1, 6
Indications
Primary Indication
- Long-term contraception for women seeking highly effective, reversible, non-hormonal birth control for up to 10 years 1
Special Populations Where Copper IUD is Particularly Indicated
- Women with contraindications to estrogen: First-line choice for women with history of deep venous thrombosis, pulmonary embolism, or coronary events 6
- Breastfeeding women: Safe to use immediately postpartum 6
- Women with diabetes or HIV infection: No contraindications 6
- Nulliparous adolescents: Safe and effective despite past concerns 1
- Women requiring emergency contraception: Can be inserted within 5 days of unprotected intercourse as highly effective emergency contraception 1
Additional Clinical Scenarios
- Immediate postpartum period: Can be inserted while still in the hospital, supported by ACOG and CDC 1
- History of ectopic pregnancy: Not a contraindication 6
- During NSAID therapy: Safe to use 6
Contraindications
Absolute Contraindications (Category 4)
Pregnancy is the only absolute contraindication to copper IUD insertion due to risk of severe pelvic infection and septic spontaneous abortion. 8, 9
Relative Contraindications (Category 3)
- Current purulent cervicitis 1
- Active gonorrhea or chlamydia infection: Increased risk of pelvic inflammatory disease with insertion 1, 8, 9
- Current pelvic inflammatory disease 1
- Other current pelvic infections 1
Important: NOT Contraindications
- Past PID: Not a contraindication to IUD use 1
- HIV infection: Not a contraindication 1, 9
- Immunosuppression: Not a contraindication 1
- Nulliparity: Not a contraindication 1
Common Pitfalls and Caveats
Infection Management
The critical window for infection risk is the first 20-21 days post-insertion; beyond this period, IUDs do not increase rates of STIs or PID. 1 If STIs or PID develop, they can be treated with the IUD in place as long as the patient improves with treatment. 1
Pregnancy Considerations
- Ectopic pregnancy: While ectopic pregnancies are rarer in IUD users than in women using no contraception, about 1 in 20 pregnancies that occur with an IUD in place is ectopic 6
- Intrauterine pregnancy with IUD: If pregnancy occurs, about 25% end in live birth if the device is left in place, compared to 90% if removed 6
Side Effects
- Increased menstrual bleeding: Copper IUDs increase menstrual blood loss by approximately 50%, often associated with dysmenorrhea 6, 5
- Most common reasons for discontinuation: Menstrual bleeding and pain 2
- However, continuation rates are high: Approximately 50% of women continue use after 5 years, which is higher than many other contraceptive methods 2
STI Protection
The copper IUD does not protect against sexually transmitted infections or HIV; condoms must be used consistently if there is STI/HIV risk. 9