Intra-uterine devices (IDs) are used to prevent:

Options

A. Sperm to reach ovum
B. Sperm to reach female
C. Sperm from leaving testes
D. All of these

Answer

**Step-by-Step Solution:**

1. **Understanding Intra-Uterine Devices (IUDs)**:
- IUDs are a form of contraceptive used to prevent pregnancy. They are inserted into the uterus and work primarily by preventing sperm from fertilizing an egg.

2. **Types of IUDs**:
- There are three main types of IUDs:
- Non-medicated IUDs (e.g., Lippes loop)
- Copper-releasing IUDs
- Hormone-releasing IUDs

3. **Function of Non-Medicated IUDs**:
- Non-medicated IUDs work by causing phagocytosis of sperm, which means they help in destroying sperm, preventing them from reaching the egg.

4. **Function of Copper-Releasing IUDs**:
- Copper-releasing IUDs release copper ions that suppress sperm motility and fertilization capability, making it difficult for sperm to reach the egg.

5. **Function of Hormone-Releasing IUDs**:
- Hormone-releasing IUDs release hormones that increase the viscosity of cervical mucus, making it harder for sperm to enter the uterus. They also create an unfavorable environment for implantation.

6. **Conclusion**:
- The primary purpose of IUDs is to prevent sperm from reaching the ovum (egg) to avoid fertilization. Therefore, the correct answer to the question is option A: "sperm to reach ovum".

**Final Answer**: Option A: Sperm to reach ovum.

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