Definition
A.Anemia in pregnancy results from decreased serum iron. The iron-binding capacity is increased. Red blood cells (RBCs) are microcytic and hypochromic. The Centers for Disease Control and Prevention (CDC) and American Congress of Obstetricians and Gynecologists (ACOG) define first- and third-trimester anemia as a hemoglobin (Hgb) of less than 11.0 g/dL and hematocrit (Hct) of less than 33%, and second-trimester anemia as an Hgb of less than 10.5 g/dL and Hct of less than 32%.
Incidence
A.Anemia is a common medical complication of pregnancy. Iron-deficiency anemia constitutes 75% to 95% of pregnancy-related anemias.
Pathogenesis
A.Increased demand for iron during pregnancy occurs because of increased maternal blood volume. Hgb and Hct decrease during the first and second trimesters because of a greater expansion of plasma volume relative to the increase in RBC mass and usually increase during the third trimester when plasma expansion has ceased
B.During most pregnancies, diet alone does not provide the necessary iron; however, in lactation less elemental iron is needed. In women 19 years and older, 9 mg/d is needed and in adolescents 10 mg/d is recommended.
Predisposing Factors
A.Failure to take oral iron; often because of inability to tolerate oral iron supplements.
B.Multiple gestation; increases iron requirement and may contribute to increased blood loss at delivery.
C.Diet high in phosphorus or foods such as tea, coffee, milk, or soy.
D.Low iron and protein diet, eating nonfood items (pica).
E.Not eating foods that help with absorption of iron (orange juice, broccoli, strawberries).
F.History of gastrointestinal surgery may cause iron malabsorption (i.e., gastrectomy).
G.Chronic bleeding during pregnancy (i.e., placenta previa, marginal sinus separation of placenta, hemorrhoidal bleeding).
H.Short intervals between pregnancies.
I.Race: Non-Hispanic Black females.
J.Age: Teenage girls.
Common Complaints
A.Tiredness.
B.Inability to take prenatal vitamins because of nausea.
C.Bleeding problems (see section Predisposing Factors
).
D.Pica.
Other Signs and Symptoms
A.Fatigue.
B.Pale mucous membranes and skin.
C.Tachycardia.
Subjective Data
A.Elicit the onset, duration, and course of presenting symptoms.
B.Elicit information about the patient’s typical
dietary intake for meals and snacks, and review pica (eating clay, starch, ice, and other nonnutritive substances).
C.Review the patient’s intake of prenatal vitamins and supplemental iron. How often does she take iron? Elicit the reason for skipping the supplemental iron (nausea, constipation), if applicable.
D.Review the patient’s history of gastrointestinal surgeries, irritable bowel syndrome (IBS), and Crohn’s disease.
E.Review the patient’s history for any type of anemia and previous treatment, including blood transfusions.
F.Review pregnancy history for closely spaced pregnancies (two in a calendar year) and multiple gestation.
G.Review the patient’s intake of medications for the use of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs).
Physical Examination
A.Check pulse and blood pressure (BP): Note postural hypotension and tachycardia.
B.Inspect: General appearance:
1.Inspect the skin, mucous membranes, and conjunctivae for pallor.
2.Observe the mouth and tongue: Note atrophy of papillae and smooth, beefy red appearance of tongue with anemia.
3.Note dryness of skin. Inspect texture of nails (brittle, spoon-shaped, concave); inspect the hair for brittleness.
C.Palpate: Palpate the abdomen for masses; assess fundal height.
D.Auscultate: Auscultate the heart for systolic flow murmurs; auscultate lungs.
Diagnostic Tests
A.Blood work: Hgb and Hct:
1.First trimester: Less than 11 g/dL Hgb or less than 33% Hct.
2.Second trimester: Less than 10.5 g/dL Hgb or less than 32% Hct.
3.Third trimester: Less than 11 g/dL Hgb or less than 33% Hct.
B.Peripheral blood smear: Note microcytic and hypochromic RBCs on peripheral smear.
C.Sickle cell screen, if applicable.
D.Serum iron: Low with anemia.
E.Iron-binding capacity: High iron-binding capacity with anemia.
F.Transferrin: Saturation less than 15%.
G.Stool for occult blood, if applicable.
H.Emesis for presence of blood, if applicable.
Differential Diagnoses
A.Iron-deficiency anemia.
B.Normal physiologic anemia of pregnancy: During normal pregnancy, concentrations of erythrocytes and Hgb usually fall because of the greater increase in plasma volume (increased by 45%) relative to the increase in erythrocyte volume (increased by 25%).
C.Megaloblastic anemia: This condition is commonly associated with iron-deficiency anemia and is rarely seen alone.
D.Hemolytic anemia: Sickle cell anemia, thalassemia, hereditary spherocytosis, and erythrocyte enzyme deficiency.
E.Aplastic anemia: Bone marrow failure.
F.Hematologic malignancies: Leukemia and lymphoma.
G.Clotting factor or other hemostatic deficiencies: von Willebrand’s disease, idiopathic thrombocytopenia (ITP), and disseminated intravascular coagulation (DIC).
Plan
A.General interventions:
1.Perform initial evaluation of Hgb and Hct at first prenatal visit; repeat at 24- to 28-week blood draw with diabetes testing.
2.Diet counseling and nutrition consultation.
3.The patient may be eligible for the Women, Infants, and Children (WIC) program that provides supplemental foods for pregnant women and young children. Ask your local health department
for information available in your community:
a.Advise the patient to take supplemental iron in addition to prenatal vitamins. If she is unable to tolerate prenatal vitamins, suggest a children’s chewable vitamin, two tablets daily.
b.Encourage the patient to continue iron supplementation through the first month postpartum and throughout breastfeeding.
B. 
See Section III: Patient Teaching Guide Anemia, Iron Deficiency.
C.Pharmaceutical therapy:
1.Prophylaxis: Increase daily elemental oral iron supplements from 15 mg/d to 30 mg/d in pregnancy to prevent iron deficiency anemia.
2.Most prenatal vitamin formulations contain 30 mg of elemental iron per day; however, if the woman has iron deficiency anemia she needs to increase her elemental iron by 30 to 120 mg/d. Nausea and vomiting occur in 20% to 25% of patients. These side effects are dose-related. Have the patient alter times of administration of the iron supplement to determine when the iron is best tolerated.
3.Treatment: With iron-deficiency anemia, three times the prophylactic dose of iron should be given. Instruct the patient to take the iron concurrently with orange juice. Vitamin C increases the absorption of iron.
4.Intramuscular (IM) or intravenous (IV) iron may be ordered for the small proportion of patients who do not tolerate oral iron because of gastrointestinal complaints, malabsorption syndrome, or noncompliance with the oral iron regimen.
5.Blood transfusion may be needed per institute guidelines.
Follow-Up
A.Carry out routine prenatal and postpartum follow-up care. When the patient begins taking the recommended dose of supplemental iron, the RBC response can be measured in 2 weeks by an elevation in her reticulocyte count.
B.Repeat Hct after 4 to 6 weeks of therapy.
C.If no improvement is seen in reticulocyte count or Hct after 4 weeks of therapy and the patient has been compliant, another cause of anemia should be investigated.
Consultation/Referral
A.Consider consult with a physician if Hgb is less than 9 g/dL or Hct is less than or equal to 27% and does not improve with the previously noted treatments.