Which one of the following is an example of Hormone releasing IUD ?

The correct answer is LNG 20.

Intrauterine Devices (IUDs) are contraceptive devices inserted into the uterus to prevent pregnancy. They are categorized based on their mechanism of action and components:

1. Non-Medicated IUDs: These are simple, inert devices (e.g., Lippes Loop) that stimulate an inflammatory response in the uterus to prevent implantation.
2. Copper-Releasing IUDs: These devices release copper ions, which suppress sperm motility and fertilizing capacity. Examples include CuT, Cu 7, and Multiload 375.
3. Hormone-Releasing IUDs: These devices release hormones (like progesterone) that make the uterus hostile to implantation, alter the cervical mucus to prevent sperm entry, and inhibit sperm activity. Examples include LNG 20 (which releases levonorgestrel) and Progestasert.

Therefore, among the options provided, LNG 20 is a hormone-releasing IUD.