Introduction: The most frequent causes of microcytic anemia among antenatal women in India are iron deficiency anemia (IDA) and beta thalassemia trait(βTT). Hence it is important to differentiate between both the conditions to avoid unnecessary iron therapy in βTT patients. This study was done to screen antenatal women with β thalassemia trait using formulas derived from various Red cell indices. Aims And Objectives: This study aims to screen all microcytic (MCV<80fl) hypochromic (MCH<27pg) anemia for β thalassemia trait, to differentiate IDA from βTT and confirm the screened cases by HPLC. Also attempt has been made to assess sensitivity and specificity of various indices to identify βTT. Materials And Methods: A cross sectional comparative study was done in 200 antenatal women for a period of 2 years from October 2019 to September 2021 in department of clinical pathology at Tertiary care hospital. Complete blood counts and various red cell indices were evaluated. There are 16 cases of hemoglobinopathies out of which 9 are β thalassemia trait and 184 cases are iron deficiency anemia. Four indices were calculated i.e., the Mentzer index (MI), Srivastava index (SV), Shine and Lal index (SL) and Red cell Distribution Width (RDW) index. These indices were calculated in patients having microcytosis (MCV<80fl) and hypochromia (MCH<27pg) and, all the cases are further subjected to HPLC for confirmation. Results: In the present study the index with highest sensitivity for diagnosing β thalassemia trait was Shine and Lal index (100%) and Mentzer index showed highest specificity with 99.5%. Positive predictive value (PPV) was highest for Mentzer index and Negative predictive value (NPV) was highest for Shine and Lal index. Youden’s index was highest for RDW. In the present study the percentage of correctly identified patients was highest for Mentzer index. Conclusion: It is vital to establish a screening model based on HbA2 levels and red cell indices for the differentiation of β TT from IDA in microcytic hypochromic anemia cases. According to the results of the present study MI and RDW index are considered as the most useful and reliable indices for screening β thalassemia trait, though HPLC confirmation is mandatory.

Introduction: The most frequent causes of microcytic anemia among antenatal women in India are iron deficiency anemia (IDA) and beta thalassemia trait(βTT). Hence it is important to differentiate between both the conditions to avoid unnecessary iron therapy in βTT patients. This study was done to screen antenatal women with β thalassemia trait using formulas derived from various Red cell indices. Aims And Objectives: This study aims to screen all microcytic (MCV<80fl) hypochromic (MCH<27pg) anemia for β thalassemia trait, to differentiate IDA from βTT and confirm the screened cases by HPLC. Also attempt has been made to assess sensitivity and specificity of various indices to identify βTT. Materials And Methods: A cross sectional comparative study was done in 200 antenatal women for a period of 2 years from October 2019 to September 2021 in department of clinical pathology at Tertiary care hospital. Complete blood counts and various red cell indices were evaluated. There are 16 cases of hemoglobinopathies out of which 9 are β thalassemia trait and 184 cases are iron deficiency anemia. Four indices were calculated i.e., the Mentzer index (MI), Srivastava index (SV), Shine and Lal index (SL) and Red cell Distribution Width (RDW) index. These indices were calculated in patients having microcytosis (MCV<80fl) and hypochromia (MCH<27pg) and, all the cases are further subjected to HPLC for confirmation. Results: In the present study the index with highest sensitivity for diagnosing β thalassemia trait was Shine and Lal index (100%) and Mentzer index showed highest specificity with 99.5%. Positive predictive value (PPV) was highest for Mentzer index and Negative predictive value (NPV) was highest for Shine and Lal index. Youden’s index was highest for RDW. In the present study the percentage of correctly identified patients was highest for Mentzer index. Conclusion: It is vital to establish a screening model based on HbA2 levels and red cell indices for the differentiation of β TT from IDA in microcytic hypochromic anemia cases. According to the results of the present study MI and RDW index are considered as the most useful and reliable indices for screening β thalassemia trait, though HPLC confirmation is mandatory.