Choosing Between Hormonal and Copper IUDs
Two IUD families act through very different local mechanisms.
- ~8 yr: Hormonal lifespan (placeholder figure)
- ~10 yr: Copper lifespan (placeholder figure)
- <1%: Failure rate (placeholder figure)
- Local: Mechanism type (not systemic)
Two distinct contraceptive strategies
Placeholder: hormonal and copper IUDs work by different local pathways.
Levonorgestrel Diffusion from the Hormonal IUD
The vertical stem releases a steady low dose of levonorgestrel.
- ~20 µg: Daily release (placeholder figure)
- Stem reservoir: Release site (placeholder)
- Very low: Systemic level (placeholder)
- Hours: Onset (placeholder)
Local hormone diffusion
Placeholder: LNG diffuses locally from the polymer reservoir into the uterine cavity.
Placeholder: local dosing minimizes systemic hormonal exposure.
Cervical Mucus Thickening Under Progestin
Thickened mucus forms a physical barrier to sperm.
- ↑ High: Mucus viscosity (placeholder figure)
- Blocked: Sperm penetration (placeholder figure)
- Continuous: Timeframe (placeholder)
- Full: Reversibility (placeholder)
Mucus as a physical barrier
Placeholder: progestin-thickened mucus impedes sperm ascent into the uterus.
Copper Ion Spermicidal Environment
Released copper ions impair sperm viability and function.
- Continuous: Cu²⁺ release (placeholder figure)
- ↓ Severe: Sperm motility (placeholder figure)
- Local: Inflammatory response (placeholder)
- Immediate: Onset (placeholder)
Copper cytotoxicity to sperm
Placeholder: copper ions create a hostile, spermicidal intrauterine environment.
Placeholder: copper acts as a direct chemical toxin, not a hormone.
Comparing Endometrial Effects
Hormonal thins the lining; copper triggers local inflammation.
- Thin/atrophic: Hormonal endometrium (placeholder figure)
- Inflamed: Copper endometrium (placeholder figure)
- ↓ Reduced: Bleeding (hormonal) (placeholder figure)
- ↑ Increased: Bleeding (copper) (placeholder figure)
Divergent endometrial outcomes
Placeholder: the two IUD types produce opposite endometrial and bleeding patterns.