Description

• Failure to thrive (FTT) is not a diagnosis but a sign of inadequate nutrition in young children manifested by a failure of physical growth, usually affecting weight. In severe cases, decreased length and/or head circumference may develop.
• Various parameters are used to define FTT, but in clinical practice, it is commonly defined as either weight or BMI for age that falls below the 5th percentile on more than one occasion or weight that drops two or more major percentile lines on standard growth charts OR weight-for-length that falls below the 5th percentile.
• A combination of anthropometric criteria rather than one criterion should be used to identify children at risk of FTT.

Pediatric Considerations

• Children with genetic syndromes, intrauterine growth restriction (IUGR), or prematurity follow different growth curves.
• 25% of children will decrease their weight or height crossing ≥2 major percentile lines in the first 2 years of life. These children are failing to reach their genetic potential or demonstrating constitutional growth delay (slow growth with a bone age < chronologic age). After shifting down, these infants grow at a normal rate along their new percentile and do not have FTT.

Epidemiology

Incidence

• Predominant age: 6 to 12 months; 80% <18 months
• Predominant sex: male = female

Prevalence

• As many as 10% of children seen in primary care have signs of growth failure.
• 1–5% of pediatric inpatient admissions are for FTT.
• Occurs more frequently in children living in poverty

Etiology and Pathophysiology

• Mismatch between caloric intake and caloric expenditure
• Often grouped into four major categories:
  • Inadequate caloric intake (most frequent)
  • Inadequate caloric absorption
  • Excessive caloric expenditure
  • Defective utilization
• Traditionally, FTT was classified as organic or nonorganic, but most cases are multifactorial.
• FTT often begins with a specific event and may lead to persistent difficulties.
• Causes of FTT can be grouped by pathophysiology (including examples):
  • Inadequate intake: breastfeeding difficulty, incorrect formula preparation, poor transition to food (6 to 12 months), poor feeding habits (e.g., excessive juice, restrictive diets), mechanical problems (e.g., oromotor dysfunction, congenital anomalies, GERD, CNS, or PNS anomalies), oral aversion, poverty, neglect/abuse, poor parent–child interaction, caregiver feeding style
  • Inadequate absorption: necrotizing enterocolitis, short gut syndrome, biliary atresia, liver disease, cystic fibrosis, celiac disease, milk protein allergy, vitamin/mineral deficiency, environmental enteric dysfunction
  • Increased expenditure: hyperthyroidism, congenital/chronic cardiopulmonary disease, HIV, immunodeficiencies, malignancy, renal disease, obstructive sleep apnea
  • Defective utilization: metabolic disorders, congenital infections (TORCH: toxoplasmosis, other agents, rubella, cytomegalovirus, herpes simplex)

Risk Factors

• Psychosocial risks (1)
  • Poverty, parent(s) with mental health disorder or cognitive impairment, ineffective parenting skills or hypervigilant parents, families with unique health/nutritional beliefs, physical or emotional abuse, substance abuse, and social isolation
• Medical risks (1)
  • Intrauterine exposures, history of IUGR (symmetric or asymmetric), congenital abnormalities, oromotor dysfunction, premature or sick newborn, infant with physical deformity, acute or chronic medical conditions, developmental delay, lead poisoning, anemia

Pregnancy Considerations
FTT is linked to intrauterine exposures, IUGR, and prematurity.

General Prevention

• Educate parents on normal feeding and parenting skills.
• Access to supplemental feeding programs (Women, Infants, and Children [WIC])
• Consider more frequent visits for children at higher risk for FTT.