Anemia is a serious problem for women of child bearing age, because it can have devastating effects on their babies.
Anemia usually is caused by deficiencies of iron and, rarely, of folic acid (folate).
Anemia develops slowly after normal stores of iron have been depleted.  Women, in general, have smaller stores of iron than men and experience blood loss through menstruation.  
Therefore, anemia is more common in women than in men.  During pregnancy, iron stores need to support the needs of mother and her growing fetus, who needs iron for the development of red blood cells, blood vessels, and muscle.
Approximately 95% of anemia cases during pregnancy are caused by iron deficiency.
Inadequate dietary intake, normal menstrual blood loss, or recent pregnancy are the most common reasons for low iron reserves in pregnant women. During late pregnancy, especially during the last trimester, the rapidly-growing placenta and fetus increase maternal iron requirements.
The mother’s body is designed to meet this higher demand for iron with a natural boost in red blood cell production. However, an even more pronounced increase in plasma volume leads to Hemodilution, or hydremia of pregnancy.
Hemodilution causes a drop values of Ht from the normal range between 38% and 45% in non-pregnant women to between 30% and 34% in late pregnancy.
This drop in red blood cell count makes it nearly impossible for women to build up their iron reserves during that time, especially with conventional prenatal vitamins that contain low amounts of poorly-absorbed iron.

Effects of Anemia during Pregnancy on Mother and Child:
If you are anemic, you may have no symptoms at all.
You may feel weak and fatigued, especially when your baby’s weight becomes more significant towards the end of your pregnancy.
Iron deficiency anemia sometimes leads to light-headedness and to mild dyspnea with activities such as climbing stairs.
More severe anemia can cause tachycardia and hypotention and requires the attention of a qualified medical professional.Maternal iron deficiency can have significant consequences for the development of your child.
A retrospective analysis conducted by the Centers for Disease Control and Prevention found an increased risk of preterm birth in mothers with low hemoglobin levels during the first two trimesters of pregnancy.
In non-African American women, moderately low maternal hemoglobin, defined as 9.0<10.0 g/dL during the first trimester and as 8.5<9.5 g/dL during the second trimester, also was associated with a higher risk of still birth.
In addition, women with hemoglobin <10 g/dL during the first twelve weeks of pregnancy had a three-fold greater risk (OR 3.14) than their non-anemic counterparts of giving birth to an infant with low birth weight.
Babies born to mothers with iron deficiency anemia usually present with low total iron stores and require dietary iron supplements. Iron supplementation of newborns is undesirable because iron can cause serious intestinal discomfort in their immature digestive systems.
Iron deficiency during gestation and lactation also is associated with changes in nervous system development and functioning. For many children, iron deficiency remains a problem for years. According to the CDC, 7% of one-to-two-year-olds in the United States are iron deficient and 2% present with iron deficiency anemia.
Children with iron deficiency anemia perform more poorly in cognition and motor skills tests and show delayed social and emotional development.

Thanks a lot Mr. muslimdoc for ur reply…  really that’s our job to educate our people about their health

thanxs a lot 4 ur reply Darkose even here in somalia anemia during pergnancy is big challenge for somali doctors although there is no studies till now about this issue but some doctors said that every 10 somali women 6 of them r anemic!!