Anaemia in pregnancy

• As iron deficiency develops, serum ferritin falls first followed by serum iron. 
Fall in Hb is a late development.

• Fall in MCV is the first indication of iron deficiency outside pregnancy but may be normal in the early stages in pregnancy

• Plasma folate shows considerable day-to-day variation. 
Red cell folate gives a better index of overall body and tissue levels

• Normal MCV does not exclude folate deficiency. 
A combination with iron deficiency can result in a normal MCV