Serum and endometrial copper, zinc, iron and cobalt with inert and copper-containing IUCDs.

Serum and endometrial copper (Cu), zinc (Zn), iron (Fe) and serum cobalt (Co) were measured in the mid-follicular and mid-luteal phases of the menstrual cycles in 30 Lippes loops users, 30 CuT-200 IUCD users and 24 matched controls by atomic absorption spectrophotometry. In the control group, there was no statistically significant difference in mean mid-luteal, compared to mid-follicular, levels of serum Cu, Zn, Fe and Co and endometrial Zn. Mid-luteal endometrium contained significantly higher mean Cu, and lower mean Fe levels. In Lippes loop users, compared to controls, the only statistically significant differences were lower mean mid-follicular serum Zn, lower mean endometrial Zn and Fe, and higher mean mid-luteal endometrial Fe. In CuT-200 users, compared to controls, there was significantly higher mean mid-follicular serum Zn and lower mean mid-luteal serum Co, higher mean mid-follicular endometrial Cu and lower mean mid-follicular endometrial Fe levels. Compared to Lippes loop, CuT-200 users had significantly higher mean mid-follicular serum Co and endometrial Cu and Zn, and lower mean mid-follicular endometrial Fe.