In the simplest of terms,<unk>  results from impaired production of red blood cells, increased destruction of red blood cells or blood loss.<unk>  can be congenital (i.e. conditions such as sickle cell<unk>  and thalassemia) or acquired (ie, conditions such as iron-deficiency<unk>  or<unk>  as a result of an infection). The causes of<unk>  during<unk>  can be subdivided into two main categories; physiologic and non-physiologic causes. Physiologic Causes Dilutional<unk> : There is an increase in overall blood volume during<unk> , and even though there is an increase in overall red blood cell mass, the increase in the other parts of the blood like plasma decrease the overall percentage of red blood cells in circulation. Non-physiologic Causes Iron deficiency<unk> : this can occur from the increased production of red blood cells, which requires a lot of iron and also from inadequate intake of iron, which increase in<unk> . Hemoglobinopathies: Thalassemia and sickle cell disease Dietary deficiencies: Folate deficiency and vitamin B12 deficiency are common causes of<unk> . Folate deficiency occurs due to diets low in lefty green vegetables, and animal sources of protein. B12 deficiency tends to be more common in individuals with Crohn's disease or gastrectomies. Cell membrane disorders: Hereditary spherocytosis Autoimmune causes: lead to the hemolysis of red blood cells (Ex: autoimmune hemolytic<unk> . Hypothyroidism and chronic kidney disease Parasitic infestations: some examples are hookworm or Plasmodium species Bacterial or viral infections Iron deficiency is the most common cause of<unk>  in the pregnant woman. During<unk> , the average total iron requirement is about 1200 mg per day for a 55 kg woman. This iron is used for the increase in red cell mass, placental needs and fetal growth. About 40% of women start their<unk>  with low to absent iron stores and up to 90% have iron stores insufficient to meet the increased iron requirements during<unk>  and the postpartum period. The majority of women presenting with postpartum<unk>  have pre-delivery iron deficiency<unk>  or iron deficiency<unk>  combined with acute blood loss during delivery.
Anemia in pregnancy
Hypercoagulability in pregnancy
Early pregnancy bleeding
Anemia of chronic disease
Gestational thrombocytopenia
Pre-eclampsia
Pre-existing disease in pregnancy
Acquired hemolytic anemia