When to Recheck Labs After Starting Iron Supplementation in a 14-Month-Old
Recheck hemoglobin or hematocrit at 4 weeks after initiating iron supplementation to confirm the diagnosis and assess treatment response. 1, 2
Initial 4-Week Follow-Up
The first laboratory reassessment should occur exactly 4 weeks after starting iron therapy, measuring hemoglobin concentration or hematocrit. 1, 2
A hemoglobin increase of ≥1 g/dL or hematocrit increase of ≥3% confirms the diagnosis of iron deficiency anemia and indicates adequate response to treatment. 1, 2, 3
If the child shows this expected response at 4 weeks, continue iron treatment for an additional 2 months (total 3 months of therapy). 1, 2
End-of-Treatment Assessment (3 Months)
Recheck hemoglobin or hematocrit at the completion of the 3-month treatment course to document resolution of anemia. 1, 2
At this point, if anemia has resolved, iron supplementation can be discontinued. 1
Long-Term Surveillance
Reassess hemoglobin or hematocrit approximately 6 months after successful treatment completion to monitor for recurrence of iron deficiency anemia. 1, 2
This delayed follow-up is critical because dietary factors (particularly excessive milk intake >24 oz daily) commonly lead to recurrence if not adequately addressed. 2, 4
When Initial Response is Inadequate
If after 4 weeks the anemia does not respond despite confirmed compliance and absence of acute illness:
Obtain additional laboratory tests including mean corpuscular volume (MCV), red cell distribution width (RDW), and serum ferritin concentration. 1, 4
Serum ferritin ≤15 μg/L confirms iron deficiency, while ferritin >15 μg/L suggests an alternative cause of anemia (such as thalassemia or chronic disease). 1, 4
Verify that the child is receiving the correct dose of 3 mg/kg/day of elemental iron administered between meals. 1, 4
Assess for interfering factors, particularly excessive cow's milk consumption (>24 oz daily), which is the most common cause of treatment failure. 2, 4
Common Pitfalls to Avoid
Do not wait longer than 4 weeks for the initial reassessment, as this is the standard timeframe to confirm diagnosis and ensure adequate response. 1, 2
Do not check ferritin levels routinely at 4 weeks unless there is inadequate hemoglobin response, as hemoglobin/hematocrit alone is sufficient to monitor treatment response in straightforward cases. 1
Failing to address excessive milk intake (>24 oz daily) is the most common reason for treatment failure and recurrence—dietary counseling must be reinforced at each visit. 2, 4
Do not discontinue treatment prematurely—the full 3-month course is necessary even after initial response at 4 weeks to adequately replenish iron stores. 1, 2