Copper IUDs have added contraceptive effects due to the presence of copper ions, copper ions are associated with an inflammatory response in the uterus, meaning sperm cannot reach the egg to fertilize it.

The copper ions of IUDs (Intrauterine Devices) are known to suppress the motility and fertilization capacity of sperms. This means that they prevent the sperm cells from moving effectively and reaching the egg for fertilization. Let's explore this in detail:

Copper ions in IUDs
- IUDs are small, T-shaped devices that are inserted into the uterus to provide long-term contraception. They are made of either copper or contain hormones.
- Copper IUDs release small amounts of copper into the uterus over time. These copper ions have a spermicidal effect, meaning they are toxic to sperm cells.

Suppression of sperm motility
- Sperm motility refers to the ability of sperm cells to move and swim towards the egg.
- Copper ions released by IUDs interfere with the normal functioning of sperm cells.
- They affect the sperm cell's ability to generate energy required for swimming, resulting in reduced motility.
- This reduced motility makes it difficult for sperm cells to reach the egg and fertilize it.

Suppression of sperm fertilization capacity
- Fertilization requires the successful fusion of a sperm cell with an egg cell.
- Copper ions have been found to affect the structure and function of the sperm cells' acrosome, a structure that contains enzymes necessary for fertilization.
- This interference with the acrosome function reduces the ability of sperm cells to fertilize an egg.

Overall effect on sperm cells
- The copper ions of IUDs not only reduce sperm motility but also decrease their fertilization capacity.
- This combination makes it highly unlikely for sperm cells to successfully fertilize an egg, providing effective contraception.

Importance of effective contraception
- The suppression of sperm motility and fertilization capacity by copper ions in IUDs is crucial for preventing unintended pregnancies.
- By creating a hostile environment for sperm cells, these devices offer a highly effective method of contraception.

In conclusion, the copper ions released by IUDs suppress the motility and fertilization capacity of sperm cells, making it difficult for them to reach and fertilize an egg. This mechanism provides an effective means of contraception for individuals using copper IUDs.