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Table 20-2

Common Anemias Encounters in Pregnancy

Type of AnemiaDiagnosisLaboratory FindingsTreatmentComments
Physiologic anemiaHemodilution due to greater increase in plasma volume (25%-50%) than RBC mass (10%-25%)Hct reduced 3%-5%NoneChanges begin by 6 wk gestation and resolve by 6 wk postpartum
Iron deficiency anemiaMicrocytic, hypochromic anemia with insidious onset resulting most often in weakness and lethargy; severe cases may cause glossitis, stomatitis, koilonychia, pica, and gastritis.

  • See Table 20-3.

  • Serum ferritin levels have the greatest sensitivity and specificity; levels <10-15 ng/mL generally indicate iron deficiency anemia.

  • Start with 60-120 mg of daily oral elemental iron.a

  • If unresponsive to or cannot tolerate oral iron or severe anemia, intravenous iron can be given.

  • Transfusion may be indicated in cases of severe anemia (Hb <6 g/dL).

  • Most common anemia encountered in pregnancy accounting for 50%-75% of cases

  • Caused by increased iron requirement needed to support increased RBC mass and fetal and placental development

Megaloblastic anemiaMacrocytic, hypochromic anemia most often encountered in the third trimester resulting in symptoms of anemia, weight loss, anorexia, roughness of the skin, and glossitis; severe cases can exhibit thrombocytopenia and leukopenia.

  • Peripheral blood smear shows hypersegmented neutrophils, oval macrocytes, and Howell-Jolly bodies.

  • Low serum folate (<2 ng/mL) or vitamin B12 (<200 pg/mL) levels depending on etiology

Folic acid 1 mg/d
or
Vitamin B12 administered orally (1 mg daily) or parentally (1 mg intramuscularly monthly) depending on cause of deficiency

  • Caused by deficiencies in folate (most common) or vitamin B12 resulting in impaired DNA synthesis with ineffective erythropoiesis

  • Deficiencies are often dietary or due to impaired absorption as seen in malabsorptive bariatric surgery procedures.

Abbreviations: Hb, hemoglobin; Hct, hematocrit; RBC, red blood cell.


aFerrous sulfate 325 mg contains 65 mg elemental iron; ferrous gluconate 300 mg contains 34 mg elemental iron.