Iron is essential in the structure of erythrocyte (red blood cells) that are designed to carry oxygen to cells throughout the body. During pregnancy the need for iron increases because the mother's blood volume increases in order to support changes in mother's body, but also the future development of the child.
Anemia is usually defined as a decrease in the amount of red blood cells or hemoglobin in the blood. It can also be defined as a lowered ability of the blood to carry oxygen. When anemia comes on slowly, the symptoms are often vague and may include: feeling tired, weakness, shortness of breath or a poor ability to exercise.