Objective To evaluate the effects of an intrauterine device producing a static magnetic field on the endometrial histology of rats.
Methods The experiments involved 20 adult female Wistar albino rats that were divided into five groups. Group 1 was sham-operated; Groups 2, 3 and 4 had a copper intrauterine device (IUD), an uncovered intrauterine magnet (IUM) or an intrauterine silicone-coated IUM, respectively, inserted into one of the uterine horns; in Group 5 an uncovered IUM was implanted subcutaneously. Six days later the rats were sacrificed; endometrial and subcutaneous tissues were harvested and examined microscopically.
Results Copper IUDs caused classical cellular infiltration through the endometrium. IUMs, producing a static magnetic field, also caused leucocyte and monocyte infiltration of the endometrium and, in addition, a significant leucocyte accumulation over the endometrial surface.
Conclusion This preliminary study reveals that an intrauterine magnet induces the accumulation of leucocytes in the uterine cavity in addition to the classic stromal infiltration caused by commercially available nonmagnetic IUDs. This activity could contribute to a greater efficacy of intrauterine contraception and should be investigated further.