Characterization of calcified deposits on contraceptive intrauterine devices.

The formation of calcified deposits on > 200 contraceptive intrauterine devices (IUD) was quantitated as a function of time in healthy women, pregnant women, and women with a pathologic lesion. The incrustment formation was significantly enhanced when inflammation occurred, but change could not be observed in cases of pregnancy. The incrustments were analyzed by x-ray diffraction, infrared spectroscopy, x-ray microprobe, and ultramicrochemical stone analysis techniques. Major components and their average w/w percent quantities in the incrustments are as follows: calcium carbonate 75%, apatite 5%, and organic matrix 20%. Earlier hypotheses on the chemical processes of deposit formation are discussed, and a new, ionic mechanism of calcification on IUD surfaces is suggested.