Normal Hemoglobin Level for a 5.5-Month-Old Infant
For a 5.5-month-old infant weighing 10 kg, the normal hemoglobin level is 11.0 g/dL or higher, with anemia defined as hemoglobin below 11.0 g/dL. 1
Age-Specific Hemoglobin Reference Range
Infants aged 0.5 to 5 years (which includes your 5.5-month-old) have a hemoglobin threshold of 11.0 g/dL, below which anemia is diagnosed 1
This threshold is consistent across major international guidelines for this age group, representing the lower limit of normal hemoglobin concentration 1
Clinical Context for This Age Group
At 5.5 months of age, infants are in a period of physiologic nadir for hemoglobin, where levels naturally reach their lowest point before gradually increasing 2
The 10 kg weight suggests this infant is growing appropriately (above average for age), which is reassuring but doesn't change the hemoglobin reference range 2
Important Clinical Considerations
If the hemoglobin is below 11.0 g/dL, further evaluation is warranted to determine the cause of anemia, including assessment for iron deficiency, nutritional deficiencies, hemolytic processes, or chronic disease 1
Serial measurements are more informative than a single value, particularly if there are clinical concerns about the infant's health status 2
Maternal and perinatal risk factors should be considered when interpreting borderline values, as these may lower the threshold for clinical concern 2
Common Pitfalls to Avoid
Do not use adult reference ranges for pediatric patients, as hemoglobin levels vary significantly by age 1
Avoid relying solely on laboratory values without clinical context—signs of pallor, poor feeding, tachycardia, or failure to thrive warrant investigation even with borderline hemoglobin levels 2
Be aware that different laboratory methods may have slight variations in measurement, though the diagnostic threshold of 11.0 g/dL remains standard 3