Cu²⁺ interfere in the sperm movement, hence suppressing the sperm motility and fertilizing capacity of sperms. The copper T is a simple intra-uterine device (IUD) made of a flexible, "T" shaped piece of plastic wrapped with a thin copper-containing wire. This shape is chosen as it fits the area around the uterus, allowing for the copper T to sit in place for years without moving around.

Function of Copper Ions in Copper Releasing IUD's

Copper-releasing intrauterine devices (IUDs) are a highly effective form of long-acting reversible contraception. These devices are inserted into the uterus to prevent pregnancy and work by releasing copper ions into the uterine cavity. The copper ions have several mechanisms of action that contribute to their contraceptive effect.

1. Suppression of Sperm Motility
Copper ions released from the IUD have a spermicidal effect, meaning they can immobilize and kill sperm cells. Copper ions are toxic to sperm and can impair their motility, making it difficult for them to reach and fertilize an egg. This mechanism primarily occurs in the uterus and fallopian tubes, where the IUD is located, thus preventing fertilization.

2. Disruption of Sperm Capacitation
Sperm capacitation is a process that occurs in the female reproductive tract, where sperm undergo physiological changes necessary for fertilization. Copper ions can interfere with this process and inhibit the capacitation of sperm. This further reduces the fertilizing capacity of sperm cells.

3. Inhibition of Sperm Survival
Copper ions released from the IUD also affect the survival of sperm cells. They can disrupt the integrity of the sperm plasma membrane and interfere with sperm metabolism, leading to decreased sperm viability. This further contributes to the contraceptive effect of copper-releasing IUDs.

4. Local Inflammatory Response
The presence of copper ions in the uterus triggers a local inflammatory response. This inflammatory environment is detrimental to sperm survival and function. It also affects the normal physiological processes involved in fertilization and implantation of a fertilized egg.

Conclusion
In summary, the function of copper ions in copper-releasing IUDs is primarily to suppress sperm motility and fertilizing capacity. Additionally, they may inhibit sperm survival, disrupt sperm capacitation, and create an unfavorable environment for implantation. These multiple mechanisms of action make copper-releasing IUDs highly effective in preventing pregnancy.