[Effect of the prolonged use of intrauterine devices and oral contraceptive on iron nutrition].

The aim of this work was to study the effect of prolonged use of intrauterine devices (IUD) and oral contraceptives (OCO) normally prescribed at outpatient clinics of the Health Service on iron nutrition. Two hundred twenty three healthy women, aged 20 to 39 years were studied. Of these, 100 were using IUD and 97 OCO for three to five years and 26 were not using any pharmacological or mechanical contraceptive method (control group). Serum ferritin was significantly higher in the OCO group compared to IUD and control groups (58.9 +/- 2.2; 26.2 +/- 2.1 and 21.1 +/- 2.4 ng/ml respectively). There was a positive correlation between serum ferritin and hemoglobin in IUD and control groups and between ferritin and transferrin saturation in the OCO and control groups. The frequency of storage iron depletion (defined as a serum ferritin < 12 ng/ml) was 6.3, 0 and 25% in the IUD, OCO and control groups respectively. The numbers for iron-deficient erythropoiesis (defined as a transferrin saturation < 15%) were 7, 3 and 4% and for iron deficiency anemia, 6.5, 0 and 8%. It is concluded that the chronic use of IUDs leads to iron depletion and that measures to improve iron nutrition among women using them should be adopted.