GSTM1 and anemia: Similarly, the present study highlighted that within a short span of 4 weeks, IV FCM significantly increased Hb by 3.6 g/dL in pregnant women with severe anemia and a significant rise in Hb by 2.74 g/dL and serum ferritin by 33 μg/L in pregnant women with moderate IDA (P < 0.001 for all).