Objective: To determine the role of red cell distribution width (RDW) and Mentzer index in differentiating between iron deficiency anemia (IDA) and anemia secondary to β-thalassemia trait.
Materials and methods: Study design: cross-sectional study.
Setting: Department of Obstetrics and Gynecology, MCH Unit I, PIMS, Islamabad.
Duration: Six months. Primigravida with hemoglobin less than 10 mg/dL was selected. All patients were investigated with serum ferritin and Hb electrophoresis for confirmation of the thalassemia trait. Primary outcome measures were the significance of RDW and Mentzer index in differentiating IDA from anemia secondary to β-thalassemia trait. Secondary outcome measures were the prevalence of IDA and β-thalassemia trait in primigravida women.
Results: Out of the total 178 women with microcytic hypochromic anemia, 164 (92.1%) had IDA, 9 (5.1%) had coexistent IDA and β-thalassemia trait, and 5 (2.8%) had β-thalassemia trait alone. The mean RDW was 20.6 ± 5.8 in IDA category, 16.4 ± 6.7 in IDA + β-thalassemia trait, and 14.1 ± 6.5 in β-thalassemia trait alone category. RDW was significantly higher in IDA category (p value = 0.01). Similarly, the mean Mentzer index was 21.0 in IDA, 16.1 in IDA + β-thalassemia trait category. However, it was significantly low 12.2 in β-thalassemia trait alone category (p value ≤ 0.001).
Conclusion: The RDW and Mentzer index have useful significance in differentiating β-thalassemia trait and IDA, it can be used as a primary tool in low resource settings.