Workup for Failure to Thrive (FTT)
The diagnostic workup for failure to thrive should include a comprehensive medical history, thorough physical examination, targeted laboratory testing, and evaluation for both organic and non-organic causes, with genetic testing recommended when clinically indicated.
Initial Assessment
Medical History
- Detailed prenatal and birth history, including polyhydramnios, prematurity, and birth weight/length 1
- Growth trajectory using standardized growth charts to document weight, height, and head circumference 1
- Feeding history, including difficulties with feeding, swallowing issues, vomiting, or gastroesophageal reflux 1
- Family history of growth disorders, genetic conditions, or metabolic diseases 1
- History of polyuria, polydipsia, dehydration episodes, unexplained fever, or recurrent vomiting 1
- Developmental milestones and neurological symptoms 1
Physical Examination
- Anthropometric measurements (weight, height/length, head circumference) plotted on growth charts 1
- Assessment for dysmorphic features suggesting genetic syndromes 1
- Evaluation of muscle tone, strength, and neurological status 1
- Examination for signs of malnutrition, dehydration, or specific nutrient deficiencies 2, 3
- Abdominal examination for hepatosplenomegaly or masses 1, 2
- Evaluation of oral cavity and dentition 1
Laboratory and Diagnostic Testing
Initial Laboratory Screening
- Complete blood count to assess for anemia, infection, or hematologic disorders 1, 2
- Comprehensive metabolic panel including:
- Thyroid function tests (TSH, free T4) 1
- Urinalysis for signs of renal tubular disorders 1
- Celiac disease screening in appropriate cases 1
Additional Testing Based on Clinical Suspicion
- Swallowing studies if feeding difficulties are present 1
- Stool studies for fat malabsorption, infection, or blood 2, 4
- Endocrine evaluation including growth hormone studies if growth failure is severe 1
- Renal ultrasound if nephrocalcinosis or renal disease is suspected 1
- Upper GI series or endoscopy for persistent GI symptoms 1
- Genetic testing when syndromic features are present or other evaluations are non-diagnostic 1
Specialized Evaluations
Gastrointestinal Assessment
- Referral to gastroenterologist for persistent feeding difficulties, reflux, or poor growth 1
- Evaluation for gastroesophageal reflux and swallowing dysfunction 1
- Assessment of pancreatic function if indicated 1, 4
Nutritional Assessment
- Detailed dietary intake evaluation 1, 4
- Assessment of feeding behaviors and parent-child interactions 2, 3
- Evaluation for specific nutrient deficiencies (vitamins, minerals) 1, 4
Developmental and Behavioral Assessment
- Developmental screening or comprehensive evaluation 1
- Assessment for feeding therapy needs 1
- Evaluation of family dynamics and psychosocial factors 2, 3
Important Considerations and Pitfalls
- Routine extensive laboratory testing has low yield (<1.4%) without specific clinical indicators and should be targeted based on history and physical examination findings 3
- Avoid premature labeling of "non-organic" FTT before adequate medical evaluation 2, 4
- Consider both organic and non-organic causes, as they often coexist 2, 4
- Early intervention is essential to prevent long-term sequelae from nutritional deficiency 2, 4
- Regular follow-up to monitor growth response to interventions is critical 1
- Consider specialized referrals (endocrinology, genetics, neurology) when initial evaluation does not identify a cause or when specific abnormalities are detected 1
Special Populations
Infants with Antenatal Concerns
- Evaluate for polyhydramnios history, which may suggest conditions like Bartter syndrome 1
- Consider genetic testing for suspected syndromes 1