Selective iron supplementation based on serum ferritin values early in pregnancy: are the Norwegian recommendations satisfactory?

Abstract

Background: The aims of the present study were to evaluate the recommendations by comparing compliance and adequacy of iron status at 6 weeks postpartum between one group given advice only and one group given advice plus iron supplement. In the latter group the efficacies of two iron preparations of different strengths and types were compared.

Methods: Ninety-three women had been given advice only (Group I) and were enrolled in the project at 6 weeks postpartum. Two hundred and thirty-three women enrolled at their second antenatal visit and were given advice plus iron supplement; those with s-ferritin <60 microg/L were randomized to a daily dose of 1) 60 mg Fe2+ (Ferromax) or 2) 3.6 mg heme iron plus 24 mg Fe2+ (Hemofer), and started taking the supplement at once if s-ferritin <20 microg/L or at 20 weeks if 20-60 microg/L. In addition to hemoglobin as routine, s-ferritin was measured in all the women at 6 weeks postpartum.

Results: At 6 weeks postpartum median s-ferritin was 28 and 34 microg/L in Groups I and II, respectively, and a significantly higher mean s-ferritin (46.5 vs. 37.3 microg/L; p < 0.05) was found in women taking the highest dose. There were no correlations between s-ferritin in early pregnancy and at 6 weeks postpartum. Peripartum blood loss was the main indicator for iron status at 6 weeks postpartum.

Conclusion: Iron supplementation based on iron status early in pregnancy, with 60 mg ferrous iron or 27 mg iron containing heme, resulted in adequate iron stores at 6 weeks postpartum among 75% or 70% of the women, respectively. However, 6 weeks were not sufficient to rebuild iron stores in women with large peripartum blood loss.