Role of Mentzer index for differentiating iron deficiency anemia and beta thalassemia trait in pregnant women

OBJECTIVE: To observe the role of Mentzer index for differentiating iron deficiency anemia (IDA) and beta thalassemia trait (β TT) in pregnant women. METHODS: This cross-sectional study was conducted in Gynaecology & Obstetrics Department of Nishtar Medical University from October 2020 to March 2021. Non-consecutive sampling was applied. A total of 100 antenatal ladies with hemoglobin <11 gm/dl were included. Their complete blood counts were checked and Mentzer Index was calculated. Mentzer Index <13 points to diagnosis of β TT and >13 indicates IDA. The diagnoses were confirmed by serum iron studies and Hb electrophoresis. The sensitivity and specificity of Mentzer Index for both causes of microcytic hypochromic anemia was calculated. RESULTS: Out of total 100 patients with microcytic hypochromic anemia, 87 had Mentzer Index >13 and IDA was confirmed in 86 out of 87 cases. Thirteen cases had Mentzer Index <13 and β TT was confirmed in eight of them. Thus, Mentzer Index has a sensitivity and specificity of 91% & 83% for IDA and 83% & 91% for β TT. CONCLUSION: In this study, it was found that Mentzer Index can be used as a discriminatory test to differentiate between iron deficiency anemia and beta thalassemia trait. The high risk group can then be subjected to definitive diagnostic tests. This can result in better patient compliance and cost effectiveness.