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Contraceptive Update: Contraceptive Pearls
(August 2003)
The "Contraceptive Pearls" offer answers to commonly asked questions about family planning. These "Pearls" were prepared by Dr. James D. Shelton, Senior Medical Scientist, Office of Population and Reproductive Health, United States Agency for International Development (USAID). They are reprinted with permission. To view archives of Jim Shelton's Pearls online, visit Jim Shelton's Pearls online
Copper IUD Tarnishing
Question: Sometimes the IUDs we get seem to have lost some of their shine. I also remember a few years back that with quite of few of them, the copper looked pretty tarnished. Does such tarnishing affect the effectiveness of the IUDs?
Answer: No. Air normally passing into the IUD package can cause oxidation to occur resulting in tarnish. The effectiveness of copper IUDs depends on release of copper ions, which are actually produced by a similar oxidative process anyway. A study carried some years ago found that when tarnished IUDs are placed in media resembling uterine fluids, the tarnish rapidly dissolved and copper release rates for the tarnished and untarnished IUDs were the same. Reference: Tsong YY, Nash H. Effect of tarnish on copper release. Contraception 1991;44:385-392.