Duration of use of copper releasing IUDs and the incidence of copper wire breakage

An analysis of the corrosion process of the nova-T IUD

“…The coil of the Nova-T, however, shows excellent mechanical stability up to 9 years of use (the oldest device seen in this study) preventing the fragmentation of the coil that occurs in a proportion of the IUDs using pure copper [17]. Consequently this examination of the rate of copper loss and the stability of the metal core gives no hint for the decline in the efficacy of the Nova-T reported after three years of use when compared with the TCu-220 IUD in the 1990 WHO multicenter trial [18].…”

Three-dimensional ultrasound imaging of an intrauterine device showing copper corrosion

“…The depletion of a copper IUD occurs through dissolution and corrosion of the metal, and may become so severe that small breakages occur and large amounts of metallic copper are lost. Thus, fragmentation is thought to compromise the efficacy of the IUD 6 . Several factors have been found to affect the rate of release of intrauterine copper, including pH, chemical characteristics of the compounds present in the uterine fluid, metabolic activity of the endometrium and the surface area of exposed copper.…”