All of the following may be observed in a normal pregnancy EXCEPT:: (A) Fall in serum iron concentration, (B) Increase in serum iron binding capacity, (C) Increase in blood viscosity, (D) Increase in blood oxygen carrying capacity
Answer is C. Blood thins out in pregnancy due to the hemodilution of pregnancy. The increase in Blood volume (30-45%) is relatively greater than that of red cell mass (20-30%) resulting in hemodilution and a decrease in haemoglobin concentration. Fibrinogen as well as factors VII , IX, X and XII increase markedly. These changes tend to prevent excessive bleeding at delivery. Pregnancy is a hyper-coagulable state thus, but this is not synonymous with "Increased viscosity" .