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Copper release from the MLCu 250 intrauterine device.


 The anchor-shaped, polyethylene MLCu 250 IUD with 27 cm of 99.9% pure copper wire was evaluated for its rate of dissolution of copper. The vertical arm of the IUD is wrapped with 0.30 mm of copper for an exposed surface area of 250 mm. The results of a study of 315 IUDs showed 14% of the copper was released after 1 year, 27% after 2 years, and 40% after 3 years in utero. Although the MLCu 250 has thicker copper wire than the TCu 200 or Cu-7 200 (each with .25 mm diameter) it was found to have less copper (60%) remaining after 3 years than the TCu 250 (85%). IUD effectiveness, however, is not solely determined by copper residual. The MLCu 250 has residual copper to provide effective contraception several years after having been worn for 3 years.
