Operational Definition of Anaemia in Women of Reproductive Age
Anaemia in women of reproductive age is defined as a hemoglobin concentration below 12.0 g/dL, according to the World Health Organization criteria. 1
Hemoglobin Thresholds
The operational definition varies slightly based on pregnancy status:
- Non-pregnant women of reproductive age: Hemoglobin <12.0 g/dL 2, 1
- Pregnant women - First trimester: Hemoglobin <11.0 g/dL 3
- Pregnant women - Second/Third trimester: Hemoglobin <10.5-11.0 g/dL (depending on guideline used) 3
- Postpartum women: Hemoglobin <12.0 g/dL 4
Severity Classification
When anemia is identified, severity grading helps guide management:
- Mild anemia: Hemoglobin ≥10.0 g/dL 3
- Moderate anemia: Hemoglobin 7.0-9.9 g/dL 3
- Severe anemia: Hemoglobin 4.0-6.9 g/dL 3
- Very severe anemia: Hemoglobin <4.0 g/dL (implied from classification) 3
Important Clinical Considerations
The hemoglobin threshold of <12.0 g/dL applies universally to non-pregnant women of reproductive age, though normal hemoglobin distribution can vary with ethnicity and physiological status. 1
Key Caveats:
- The definition is based on hemoglobin concentration, which can also be expressed as low red blood cell count or low hematocrit 3
- In pregnancy, physiological hemodilution occurs, which explains the lower thresholds compared to non-pregnant women 3
- Some evidence suggests that normal hemoglobin values may need adjustment based on ethnicity, though the WHO standard of <12.0 g/dL remains the operational definition for screening and diagnosis 1
Practical Application:
In clinical practice, screening should measure hemoglobin using validated methods (such as complete blood count or HemoCue hemoglobinometer) 2, with any value below the 12.0 g/dL threshold in non-pregnant reproductive-age women warranting further evaluation to determine the underlying cause 3, 5