In a breastfed infant presenting with anemia, what is the recommended work‑up and treatment for iron‑deficiency anemia, including laboratory evaluation, oral iron dosing, dietary iron sources, and assessment of the mother’s iron status?

Management of Iron-Deficiency Anemia in Breastfed Infants

For a breastfed infant presenting with anemia, initiate oral iron therapy at 3 mg/kg/day of elemental iron administered between meals, confirm the diagnosis with a repeat hemoglobin after 4 weeks (expecting ≥1 g/dL rise), continue treatment for 2 additional months after normalization (total ~3 months), and counsel parents on iron-rich complementary foods while assessing whether the infant received adequate dietary iron after 6 months of age. 1, 2

Initial Laboratory Evaluation

When a breastfed infant presents with suspected anemia, obtain the following:

• Hemoglobin (Hb) or hematocrit (Hct) as the initial screening test, using age-specific cutoffs: Hb <105 g/L at 4-6 months or <100 g/L at 9 months defines anemia 3, 4
• Repeat the test if positive to confirm the result before initiating treatment 1
• If the infant is not acutely ill and tests confirm anemia, make a presumptive diagnosis of iron-deficiency anemia and begin empiric treatment 1

Common pitfall: Do not delay treatment waiting for ferritin or other confirmatory tests in an otherwise healthy infant with anemia—the therapeutic trial itself serves as a diagnostic tool. 1

Oral Iron Treatment Protocol

Dosing and Administration

• Prescribe 3 mg/kg/day of elemental iron in drop formulation 1, 2
• Administer between meals to maximize absorption, though this may increase gastrointestinal side effects 2, 5
• If GI intolerance occurs, consider giving with small amounts of food or switching formulations, but emphasize the importance of compliance 5

Monitoring Response

• Recheck Hb or Hct after 4 weeks of treatment 1, 2
• An increase of ≥1 g/dL in Hb or ≥3% in Hct confirms iron-deficiency anemia as the diagnosis 1, 2
• If confirmed, continue iron for 2 additional months (total treatment duration ~3 months) to replenish iron stores 2, 5
• Recheck Hb/Hct after completing treatment, then reassess approximately 6 months later 1

Non-Response Algorithm

If anemia does not improve after 4 weeks despite documented compliance and absence of acute illness: 1, 2

• Obtain MCV, RDW, and serum ferritin 1, 2
• Serum ferritin ≤15 μg/L confirms iron deficiency; >15 μg/L suggests an alternative cause of anemia 1, 2
• Consider other diagnoses such as thalassemia trait, chronic inflammation, or lead toxicity 4, 6

Common pitfall: Ferritin and transferrin receptors are less useful as initial screening tests in infants and should be reserved for cases that fail to respond to empiric iron therapy. 4

Dietary Counseling and Prevention

Identifying the Underlying Cause

Assess whether the infant received adequate iron after 6 months: 1, 3

• Breastfed infants require iron supplementation (~1 mg/kg/day) starting at 6 months if complementary foods do not provide sufficient iron 3
• Maternal iron supplementation does not increase breast milk iron content (only ~0.35 mg/L), which is insufficient beyond 6 months 3
• 15-25% of exclusively breastfed infants develop iron deficiency by 9-12 months without adequate dietary iron 3

Iron-Rich Complementary Foods

Counsel parents to provide: 3, 2

• Iron-fortified infant cereal (≥2 servings daily can meet requirements) 3
• Pureed meats when developmentally ready (after 6 months) for heme iron 3, 2
• Vitamin C-rich foods (fruits, vegetables, juices) with meals to enhance non-heme iron absorption 3, 2
• Limit cow's milk to <24 oz/day in children 1-5 years; avoid entirely before 12 months 1, 3, 2

Common pitfall: Prolonged exclusive breastfeeding beyond 6 months without iron-rich complementary foods is a well-documented cause of iron-deficiency anemia, even in toddlers up to 2-3 years of age. 7, 6

Assessment of Maternal Iron Status

Maternal iron supplementation is not an effective strategy to prevent infant iron deficiency because breast milk iron content remains low (~0.35 mg/L) regardless of maternal iron status. 3 Therefore:

• Focus counseling on the infant's dietary iron intake rather than maternal supplementation 3
• If the mother has concerns about her own iron status, address this separately but do not rely on it to improve the infant's iron supply 3

Screening Recommendations for High-Risk Infants

Screen the following breastfed infants at 9-12 months and again 6 months later: 1, 3

• Infants who did not receive adequate iron from complementary foods after 6 months 1, 3
• Preterm or low-birthweight infants (who should have started iron 2-4 mg/kg/day at 1 month) 3
• Infants introduced to cow's milk before 12 months 1, 3
• Infants consuming >24 oz/day of cow's milk 1
• Infants from low-income families (WIC-eligible, migrant, or refugee populations) 1

Common pitfall: Do not delay screening until symptoms appear—anemia in breastfed infants typically manifests at 9 months, but prevention should begin at 6 months with iron-rich foods or supplementation. 3, 7