Overview
Definition:
Failure to Thrive (FTT) is a term used to describe a child who is not growing at a normal rate
It is typically defined as a weight below the 3rd percentile for age and sex, or a deceleration in growth (crossing two or more major percentile lines on a growth chart) from a previously established growth curve
FTT is not a diagnosis in itself but a sign of an underlying problem.
Epidemiology:
FTT is seen in approximately 5-10% of infants and young children presenting to primary care settings
It is more common in lower socioeconomic populations, but can occur in any setting
Premature infants and those with chronic medical conditions are at higher risk.
Clinical Significance:
Untreated FTT can lead to irreversible physical and cognitive developmental deficits, compromised immune function, increased susceptibility to infections, and long-term health problems
Early identification and intervention are crucial to optimize outcomes.
Etiology
Nutritional Deficiency:
Inadequate caloric intake due to poverty, neglect, feeding difficulties, lack of parental knowledge, or picky eating
Increased caloric needs from hypermetabolic states or malabsorption syndromes.
Gastrointestinal Issues:
Gastroesophageal reflux disease (GERD), malabsorption (e.g., celiac disease, cystic fibrosis), pyloric stenosis, intestinal obstruction, and eosinophilic esophagitis can all impair nutrient absorption and intake.
Chronic Illness:
Congenital heart disease, chronic lung disease, renal disease, endocrine disorders (e.g., hypothyroidism, diabetes), and chronic infections increase metabolic demands or impair nutrient utilization.
Neurological Impairment:
Cerebral palsy, developmental delay, or genetic syndromes can lead to feeding difficulties, dysphagia, or decreased appetite.
Psychosocial Factors:
Parental mental health issues (depression, substance abuse), neglect, abuse, and lack of caregiver-child bonding can significantly impact a child's nutritional status.
Diagnostic Approach
History Taking:
Detailed feeding history: type of milk/formula, volume, frequency, duration of feeds, presence of vomiting or regurgitation
Stool characteristics: frequency, consistency, presence of blood or mucus
Developmental milestones
Family history of growth problems or chronic illnesses
Psychosocial assessment of the home environment
Assess for signs of neglect or abuse.
Physical Examination:
Assess growth parameters using standardized growth charts (weight, height, head circumference)
Look for dysmorphic features suggestive of genetic syndromes
Perform a thorough head-to-toe physical examination, focusing on signs of underlying disease (e.g., cardiac murmurs, pulmonary rales, abdominal distension, neurological deficits)
Assess skin turgor and hydration status.
Investigations:
Complete blood count (CBC) to assess for anemia
Electrolytes, BUN, creatinine for hydration and renal function
Liver function tests (LFTs)
Thyroid function tests (TFTs)
Stool studies for infection, fat, or occult blood
Urinalysis
Consider celiac screen (tissue transglutaminase antibodies), sweat chloride test for cystic fibrosis, or metabolic screening if indicated
Imaging may include abdominal ultrasound or barium studies to rule out structural abnormalities.
Differential Diagnosis:
Distinguish FTT from constitutional small stature or familial short stature
Consider conditions causing poor feeding, increased caloric expenditure, or malabsorption
Rule out acute illness or dehydration masquerading as FTT.
Management Caloric Density
Goal:
To achieve adequate weight gain and catch-up growth, restoring the child's growth to their genetically determined potential.
Caloric Requirements:
Initial daily caloric targets are typically 120-150 kcal/kg/day, with fluid intake of 150-200 mL/kg/day
These requirements can be higher in severe FTT or with malabsorption.
Optimizing Caloric Density:
Increase the caloric density of feeds by: adding infant formula or breast milk to existing feeds
Using higher caloric density formulas (e.g., 24 kcal/oz or 30 kcal/oz)
Adding maltodextrin or vegetable oil (1-2 tsp per 4 oz) to formula or breast milk
For older children, incorporating healthy fats like avocado, nut butters, and olive oil into meals.
Feeding Methods:
Frequent, small feeds (every 2-3 hours) can prevent gastric distension and improve tolerance
For infants with significant feeding difficulties or poor oral intake, consider nasogastric (NG) or orogastric (OG) tube feeding
In severe cases, a gastrostomy tube may be necessary.
Catch Up Growth
Definition Catch Up:
Catch-up growth is the accelerated growth rate that occurs after a period of growth inhibition, allowing the child to reach a higher percentile on growth charts
It is characterized by a growth velocity exceeding the normal range for age and sex.
Factors Influencing Catch Up:
The effectiveness of catch-up growth depends on the duration and severity of the growth insult, the promptness and adequacy of nutritional rehabilitation, and the absence of underlying chronic disease or genetic limitations
Age is a critical factor
younger children generally have a greater capacity for catch-up growth.
Monitoring Catch Up:
Regular monitoring of weight, height, and head circumference is essential
A sustained weight gain of 20-40 grams per day in infants and 5-10 grams per day in older children is considered adequate catch-up growth
The goal is to return to the child's original growth channel or a channel consistent with their genetic potential
The rate of catch-up is typically highest for weight, followed by height, and lastly head circumference.
Nutritional Strategies For Catch Up:
Achieving adequate caloric intake is paramount
This involves a combination of increased caloric density of foods and appropriate feeding strategies
Micronutrient supplementation (e.g., iron, zinc, vitamins) may be necessary if deficiencies are identified or suspected
Psychological support for the child and caregivers is crucial to address feeding aversions and ensure adherence to the feeding plan.
Key Points
Exam Focus:
Understand the definition of FTT and its common causes
Recognize the importance of growth charts for diagnosis and monitoring
Differentiate between organic and inorganic FTT
Know the principles of increasing caloric density and calculating caloric needs for catch-up growth
Be familiar with feeding methods and when to consider tube feeding.
Clinical Pearls:
Always start with a thorough growth chart analysis
A detailed feeding history is critical
Involve a multidisciplinary team (dietitian, social worker, psychologist) for comprehensive management
Address psychosocial factors early as they are often overlooked but crucial for sustained weight gain
Monitor for refeeding syndrome in severely malnourished children initiating aggressive nutritional rehabilitation.
Common Mistakes:
Attributing FTT solely to picky eating without investigating underlying medical causes
Inadequate follow-up and monitoring of growth
Underestimating the caloric needs for effective catch-up growth
Failing to address psychosocial issues impacting feeding
Not considering malabsorption or chronic illness as primary drivers.