Background: Iron deficiency anemia (IDA) is most common cause of anemia in pregnancy. In order to prevent this iron supplementation is routinely practiced as a prophylactic measure in pregnant women all over. The biochemical parameters assessed in IDA comprise an iron profile evaluation which consists of estimation of serum ferritin, serum iron, total iron binding capacity(TIBC), serum transferrin levels and calculation of transferrin saturation. These biochemical parameters are subjected to variations due to maternal adaption phenomenon. Aim: In the current study we have chosen three iron indices, serum iron, serum TIBC and transferrin saturation percent to note their performance in diagnosing and monitoring the response to iron therapy in pregnant women. Methodology: The study population are thirty- six pregnant women in their early second trimester, who are diagnosed with mild iron deficiency anemia (Hemoglobin between 9 and 11 g %). Iron parameters, serum iron, serum TIBC and transferrin saturation levels were analyzed in these women. They are then given oral iron preparation in the form of Ferrous sulphate for a period of twelve weeks. After this the Hemoglobin level, serum iron, TIBC and transferrin saturation levels are re-analyzed in these women. Results: The hemoglobin levels increased (p= 0.002). as expected after oral iron intake. Serum iron levels improved from 58.19±39.07 to 64.78±34.96 μg/dl. Serum TIBC value before supplementation 234.22±134.49 increased to 437.33±94.95 after, which contradicts the expected pattern seen in response to therapy in general population. Similarly absurdity prevails in transferrin saturation index levels which dropped from 36.8 ± 31.8 to 16.3 ± 10.6. Conclusion: The iron status during pregnancy is highly influenced by the maternal changes. And a blind interpretation of the report can lead to erroneous diagnosis. The interpretation of values should be based on the trimester specific reference ranges during pregnancy.