Table 1.
Interpretation and risk–benefit analysis of maternal iron supplementation during pregnancy based on whether hemoglobin or ferritin was used as the primary biomarker to assess iron status and the information added by a second biomarker
| Primarymarker | Literatureinterpretation | Biochemical interpretation with second biomarker | Agreement between literature and biochemical finding? | Low hepcidin (likely response to therapy) | Estimate of risk-benefit of routine supplementationa |
|---|---|---|---|---|---|
| Hemoglobin | |||||
| Low | Iron-deficiency anemia | Low ferritin: iron-deficiency anemia | Low ferritin: yes | Low ferritin: yes | B ≫ R |
| Normal ferritin: anemia of inflammation | Normal ferritin: unknown because total-body iron is unmeasurable | Normal ferritin: no | Unknown, but R > B because iron will not be absorbed in high hepcidin state | ||
| High ferritin: anemia of inflammation | High ferritin: unknown because total-body iron is unmeasurable | High ferritin: no | |||
| Normal | Iron sufficient | Low ferritin: low-iron state | Low ferritin: no | Low ferritin: yes | B > R |
| Normal ferritin: iron sufficient | Normal ferritin: yes | Normal ferritin: no | Unknown | ||
| High ferritin: iron overload | High ferritin: no | High ferritin: no | R > B | ||
| High | Iron sufficient | Low ferritin: polycythemia by volume contraction or other non-iron-related condition | Low ferritin: nonanemia iron deficiency | Low ferritin: yes | R > B |
| Normal ferritin: polycythemia by volume contraction or other non-iron-related condition | Normal ferritin: iron overload | Normal ferritin: no | R > B | ||
| High ferritin: iron overload | High ferritin: iron overload | High ferritin: no | R > B | ||
| Ferritin | |||||
| Low | Low-iron state | Low hemoglobin: iron-deficiency anemia | Low hemoglobin: partly | Low hemoglobin: yes | B ≫ R |
| Normal hemoglobin: nonanemia iron deficiency | Normal hemoglobin: yes | Normal hemoglobin: yes | B > R | ||
| High hemoglobin: polycythemia by volume contraction or other non-iron-related condition | High hemoglobin: no | High hemoglobin: no | R > B | ||
| Normal | Iron sufficient | Low hemoglobin: anemia of inflammation | Low hemoglobin: no | Low hemoglobin: no | R > B |
| Normal hemoglobin: iron sufficient | Normal hemoglobin: yes | Normal hemoglobin: no | Unknown | ||
| High hemoglobin: polycythemia by volume contraction or other non-iron-related condition | High hemoglobin: no | High hemoglobin: no | R > B | ||
| High | Iron sufficient | Low hemoglobin: anemia of inflammation | Low hemoglobin: no | Low hemoglobin: no | R > B |
| Normal hemoglobin: iron overload | Normal hemoglobin: no | Normal hemoglobin: no | R > B | ||
| High hemoglobin: iron overload | High hemoglobin: no | High hemoglobin: no | R > B | ||
Abbreviations: B, benefit; R, risk.
a
Estimate of whether the risk (R) of adverse outcomes or the benefit (B) associated with iron supplementation is greater, given each combination of iron markers.