Worked Problem: Identifying IUD Type from Mechanism
Problem Statement: A 30-year-old woman cannot use any estrogen or progestogen-containing contraceptive due to a hormone-sensitive condition. She wants an IUD. Which IUD can she use, and what is the mechanism?
Step 1: Classify the IUDs in the NEET syllabus
- Cu-T, Cu-7, Multiload 375 → Copper-releasing IUDs (NON-HORMONAL)
- LNG-20 → Hormone-releasing IUD (releases LEVONORGESTREL = progestogen; HORMONAL)
Step 2: Identify which is hormonal
- LNG-20 releases levonorgestrel (a progestogen) → CANNOT be used by this patient.
Step 3: Identify the appropriate option
- Cu-T (or Cu-7 or Multiload 375) releases Cu2+ ions → NON-HORMONAL → SUITABLE.
Step 4: Describe the mechanism Cu-T works by:
- Spermicidal effect: Cu2+ ions are directly toxic to sperm, reducing their motility and viability.
- Enhanced phagocytosis: Cu2+ ions trigger a local inflammatory response, increasing the activity of uterine macrophages that engulf (phagocytose) sperm.
- Anti-implantation: The inflammatory environment also makes the endometrium inhospitable for implantation.
Answer: The patient should use Cu-T (or Cu-7 or Multiload 375). The mechanism is non-hormonal: Cu2+ ions are spermicidal and increase phagocytosis of sperm, with secondary anti-implantation effects.
NEET Connection: This question tests: (1) Classification of IUDs as copper vs hormonal, (2) Non-hormonal contraceptive options (Cu-T + Saheli), (3) Specific mechanism of Cu-T.