Scanning electron microscopy of copper-containing intrauterine devices: long-term changes in utero

The addition of metallic copper wire to a polyethylene intrauterine device dramatically increases the efficacy of that device. A series of copper-containing Tatum-T devices which had been carried in utero for 2 to 3 years was examined by scanning electron microscopy. Few of these devices showed evidence of corrosion or pitting of the copper, as had been reported previously. Almost all of the Ts showed a definite pattern of layering of fibrinoid deposits; intact cells, cellular debris, and crystalline structures were also seen. The micrographs show an extensive buildup of surface layers which, we believe, encase the copper in a semipermeable matrix. This matrix may retard the diffusion of copper compounds into the uterus sufficiently to compromise the contraceptive action of the copper.