Concentrations of copper in human secretions and weight of the copper wire during the 4 to 7 years after insertion of a Cu-IUD (intrauterine device).

The useful life span of the two most commonly used copper intrauterine devices (Cu-IUDs) (Gravigard and Cu-T) was investigated in a long-term study up to 90 months after insertion. Minor differences between the two types of devices were found that, however, probably do not contribute to a diverging contraceptive efficacy with time. To be able to ensure maximal contraceptive effect, the authors suggest on the basis of the present data that the time of use not exceed 5 to 6 years.