Diagnostic Challenges in Maternal Anemia: Mentzer Index in Clinical Practice

Maternal anemia is a significant health concern during pregnancy, as it poses risks for both maternal and fetal well-being. Two common causes of microcytic anemia in pregnant women are iron deficiency anemia (IDA) and thalassemia trait (TT). Distinguishing between these conditions is crucial, as their management differs substantially. The Mentzer Index (MI), a simple diagnostic tool, is commonly used to differentiate between IDA and TT based on the mean corpuscular volume (MCV) and red blood cell (RBC) count. However, while the MI is widely used due to its simplicity and cost-effectiveness, its accuracy can be influenced by various factors, including the presence of mixed anemia, laboratory errors, and coexisting conditions. This review explores the diagnostic challenges of maternal anemia and evaluates the role of the Mentzer Index in clinical practice. We discuss how the MI can be helpful in initial screening, particularly in resource-limited settings, but highlight its limitations in cases of complex anemia, such as when thalassemia trait coexists with iron deficiency. We also examine the role of complementary diagnostic methods, such as serum ferritin, hemoglobin electrophoresis, and genetic testing, which can improve diagnostic accuracy and guide treatment decisions. Keywords: Maternal anemia, Mentzer Index, diagnostic challenges, iron deficiency anemia, thalassemia trait