[Degradation of copper IUDs in utero. The process of metallic corrosion. A scanning electron microscope study].

OBJECTIVE

The present investigation was carried out in order to study the process of metallic corrosion of copper IUD's in utero, to precise its dynamics and location along the IUD and to appraise the influence of eventual calcareous deposition.

MATERIAL AND METHODS

A total of 461 copper IUDs representing four standard models were screened by means of optical microscopy. Especially typical samples were studied at higher magnifications under the scanning electron microscope. The obtained data were considered in terms of statistics.

RESULTS

It was possible to demonstrate a preferential corrosive activity in the lower part of the IUD without significant variations between the models. It was also possible to precise the steps of the process, to describe its most characteristic aspects and to study the eventual effect of severe calcareous deposition on corroded copper.

DISCUSSION AND CONCLUSIONS

Intrauterine copper corrosion is a normal process which occurs preferentially in the cervical portion of an IUD and can lead to the total metal loss. Both its initiation and evolution are submitted to strong individual variations. Thick and compact vaterite deposits may thwart copper erosion in case of drastic and rapid deposition.