Failure To Thrive

Failure to thrive, increasingly termed faltering growth, describes inadequate weight gain or downward crossing of expected growth centiles. It is a clinical pattern rather than a single diagnosis.

Causes broadly reflect inadequate caloric intake, impaired absorption, increased metabolic demand, excessive nutrient losses, or a combination.

Most cases involve inadequate intake, but persistent growth failure should trigger assessment for chronic infection, gastrointestinal disease, congenital heart disease, renal disease, endocrine disorders, neurological impairment, feeding dysfunction and psychosocial factors.

Weight faltering usually precedes impairment of linear growth. Severe prolonged undernutrition eventually affects height and head growth.

Look for:

• Poor weight gain or weight loss
• Feeding difficulty, prolonged feeds or feed refusal
• Vomiting or chronic diarrhoea
• Recurrent respiratory symptoms
• Developmental delay
• Abnormal stool pattern
• Recurrent infections
• Features of micronutrient deficiency
• Signs of neglect or significant feeding dysfunction

Disproportionately short stature with relatively preserved weight suggests an endocrine or skeletal cause rather than simple caloric deficiency.

• Plot serial weight, length or height and head circumference on appropriate growth charts. A single measurement is far less useful than trajectory.

• Obtain a detailed feeding history including breastfeeds, formula preparation, complementary foods, meal frequency, feeding duration and caregiver child interaction.

• Directly observe a feed where possible.

• Investigations should be targeted rather than routine. Consider FBC, renal function, electrolytes, urinalysis, coeliac testing, HIV or TB testing, thyroid function and stool studies according to clinical findings.

• Assess for severe acute malnutrition separately using MUAC, weight for height or length Z score and nutritional oedema.

• Correct the underlying cause and establish adequate energy and protein intake.

• Increase caloric density rather than simply increasing feed volume when volume tolerance is poor.

• Treat iron deficiency, infection, malabsorption and micronutrient deficiency.

• Dietitian input is valuable when catch up growth is required.

• Reassess weight trajectory rather than judging response from a single follow up measurement.

• Admission is appropriate for severe malnutrition, significant dehydration, serious underlying disease, safeguarding concern or failure of outpatient nutritional rehabilitation.