[Physico-chemical fate of copper intrauterine devices]

Often when copper intra-uterine contraceptive devices are removed they are found to have deposits on them. Studying these deposits with photonic microscopes and with scanning electronic microscopes and with fluorescence X and X diffraction shows that mostly these deposits are of calcium in the form of calcite. These crystals are not toxic but the fact that they are crystalline could give rise to microtraumatism. The study also shows that there are individual variations between patient and patient and the length of time these intra-uterine devices have been in the uterus is not an important factor in the appearance of these deposits. The phenomenon of dissolution and recrystallisation in situ of the calcite can be a trap because it can be a reservoir for micro-organisms.