Peds

Failure to Thrive Diagnosis

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Failure to Thrive Diagnosis, Growth Faltering Diagnosis, Anthropometric Z Score

  • See Also
  1. Delayed Growth
  2. Failure to Thrive
  3. Failure to Thrive Causes
  4. Failure to Thrive Red Flags
  5. Failure to Thrive Evaluation
  6. Failure to Thrive Management
  • Precautions
  1. Defining whether a child's growth is normal is difficult due to conflicting guidelines and growth curves
  2. Diagnosis relies on accurately recorded weight and height on growth chart over time
  • Evaluation
  • Initial Criteria
  1. Expect False Positives with screening criteria as below
    1. Anthropometric Z Scores have replaced these criteria for diagnosis
  2. Growth Faltering Screening relies on accurately recorded weight and height on growth chart over time
    1. Weight below 5th percentile for gender and Corrected age OR
    2. Weight for Length <5th percentile OR
    3. BMI for age <5th percentile OR
    4. Decreased Growth Velocity with Weight for Length falling by more than 2 major percentile lines
  3. Growth Faltering Diagnosis is based on anthropometric Z-Scores
    1. Z Scores are calculated from Weight for Length or BMI for age and range from -3 to +3
    2. Negative Z Scores represent lower than expected weight
    3. More negative values represent more severe Malnutrition (-1=mild, -2=moderate, -3=severe)
    4. Drop in Z-Score over time is also used to determine severity (drop of 1 = mild, drop of 2 = moderate, drop of 3 = severe)
  4. Resources
    1. Z-Score for ages 0 to 2 years (WHO)
      1. https://peditools.org/growthwho/
    2. Z-Score for ages 2 to 20 years (CDC)
      1. https://peditools.org/growthpedi/
  • Evaluation
  • Re-evaluate growth in relation to normal modifiers of growth pattern
  1. Growth may be adequate for genetic predisposition or Breast Feeding versus Bottle Feeding
    1. See Resources under Weight Measurement in Children (particular attention to WHO growth curves)
  2. Interpret trends (3rd percentile may be normal if always following 3rd percentile)
  3. Consider using modified growth charts
    1. Prematurity
    2. Ethnicity
    3. Down's Syndrome
    4. Turner's Syndrome
  • Evaluation
  • Further evaluate with most specific indicators of abnormal growth
  1. Anthropometric Z Scores (see above)
  2. Weight <75% of median Weight for Length
  3. Weight Velocity <5th percentile
  • Resources
  1. CDC Growth Charts (includes WHO charts for under age 2 years)
    1. http://www.cdc.gov/growthcharts/
  • References
  1. Goodwin (2023) Am Fam Physician 107(6): 597-603 [PubMed]
  2. Homan (2016) Am Fam Physician 94(4): 295-9 [PubMed]
  3. Olsen (2007) Arch Dis Child 92(2): 109-14 [PubMed]