What blood work is recommended for a 15-month-old child with no underlying medical conditions?

Recommended Blood Work for a 15-Month-Old Child

For a healthy 15-month-old with no underlying medical conditions, obtain a hemoglobin or hematocrit to screen for anemia, and perform blood lead testing if the child is enrolled in Medicaid, lives in an area with universal screening recommendations, or has identifiable risk factors. 1

Anemia Screening

Universal Screening Recommendation

• All children should receive hemoglobin or hematocrit screening between 9-12 months of age, with repeat screening at 15-18 months (6 months after the initial screen). 1
• The CDC recommends this two-screening approach because iron deficiency can develop rapidly during the second year of life as children transition off iron-fortified formula, adopt toddler dietary patterns, and increase cow's milk consumption. 1
• Among high-risk children with normal blood lead levels at 12 months, 21% developed anemia when retested after age 2 years, demonstrating the importance of repeat screening. 1

Risk Factors Requiring Screening at 15 Months

Screen children with any of the following risk factors: 1

• Preterm or low birthweight infants
• Infants fed non-iron-fortified formula for >2 months
• Introduction of cow's milk before 12 months of age
• Breastfed infants without adequate iron supplementation after 6 months
• Children consuming >24 oz of cow's milk daily
• Special health-care needs (medications interfering with iron absorption, chronic infections, inflammatory disorders, restricted diets, or history of significant blood loss)
• Low-income families or limited food access

Testing Method

• Either hemoglobin concentration or hematocrit is acceptable for screening. 1
• Age-specific reference ranges must be used, as adult reference ranges would misclassify approximately 30% of children aged 1-5 years as abnormal. 1

Blood Lead Screening

Federal Medicaid Requirements

• All children enrolled in Medicaid must receive blood lead testing at 12 and 24 months, with additional testing at 36-72 months if not previously screened. 1
• Despite this requirement, screening rates remain low (<20% in many areas), representing a significant gap in preventive care. 1

Targeted Screening for Non-Medicaid Children

For children not enrolled in Medicaid, perform blood lead testing at 15 months if: 1

• Living in geographic areas with high lead exposure risk (check state/local screening plans at CDC website)
• Membership in high-risk groups
• Positive responses on personal risk assessment questionnaire (residence built before 1978, recent home remodeling, use of traditional remedies/cosmetics/imported spices)
• Living in areas without established screening plans (universal testing recommended)

Rationale for Repeat Testing

• Lead exposures change with developmental milestones (walking, reaching window sills) and external factors (family relocation, home remodeling). 1
• Two routine screenings at approximately ages 1 and 2 years capture these evolving risks. 1

Blood Work NOT Routinely Recommended

Complete Blood Count with Differential

• Routine CBC is not indicated for asymptomatic, healthy children. 1
• Annual blood work for early detection of leukemia/lymphoma in healthy children lacks evidence of benefit and is no longer recommended even for children with genetic predispositions like ataxia-telangiectasia. 1
• CBC should only be obtained if the child appears ill, has hepatosplenomegaly on examination, or has specific clinical symptoms suggesting hematologic disease. 1

Coagulation Studies

• Routine screening for bleeding disorders (PT, aPTT, platelet count) is not indicated in asymptomatic children without bruising concerns or bleeding history. 1
• These tests should only be performed when evaluating unexplained bruising, bleeding symptoms, or before surgical procedures in children with concerning personal or family bleeding history. 1

Critical Pitfalls to Avoid

• Do not use adult reference ranges for pediatric laboratory values—this leads to misdiagnosis in up to 30% of children and triggers unnecessary costly workups including repeat testing, mixing studies, and factor assays. 1
• Do not skip the 15-18 month anemia recheck—iron deficiency commonly develops during the second year of life after weaning from iron-fortified formula, and early detection prevents neurodevelopmental consequences. 1, 2
• Do not perform blood lead testing during acute illness—this can affect results and should be deferred until the child recovers. 1
• Do not order routine screening blood work beyond hemoglobin/hematocrit and lead testing in healthy children—this generates false positives, unnecessary anxiety, and healthcare costs without evidence of benefit. 1