Background: The copper intrauterine device (IUD) is a highly effective method of contraception that requires the dissolution of the copper into uterine cavity. However, there is little information about the amount and form of copper in the fluid and whether the presence of this element produces any change in the protein concentration.
Methods: Twenty-seven women were divided into three groups that had used IUD for about 6 months, 1 year and > or =3 years. The samples were collected during the proliferative phase (Pp), secretory phase (Sp) and menstruation (M). Square-wave anodic stripping voltammetry (SWASV), cyclic voltammetry (CV), high performance liquid chromatography (HPLC) and atomic absorption spectrometry (AAS) were used in this study.
Results: Total copper concentrations were between 3.9 and 19.1 micro g/ml. The mean and standard deviations were as follows: 6 months, 11.4+/-4.7 micro g/ml of copper; 1 year, 11.5+/-7.0 micro g/ml of copper; and 3 years, 6.2+/-1.5 micro g/ml of copper. Total proteins were quantified by measuring the area under the chromatographic peaks. The mean areas obtained with uterine fluid samples from women who used IUDs for 6 months, 1 year and 3 years were 290,013, 538,934 and 201,863 arbitrary units (AU), respectively. The control sample was only 22323.
Conclusions: The amount of copper released from IUD, although high, is in the form of complexes with proteins. IUDs have a constant copper release for at least 6-12 months. Copper(I) was not detected in the fluid. Copper induces a change in the total protein concentration. The amount of copper released and the amount of proteins is slightly larger during the menstrual stage.