Virtual Medical Library Home | Table of Contents

 

Failure to Thrive

Michael A. Davis, MD

 

Failure to thrive (FTT) is usually first considered when a child is found to weigh less than the third percentile of norms for age and gender. Although FTT occurs in all socioeconomic strata, it is more frequent in families living in poverty. FTT describes a sign -- it is not a diagnosis. The underlying etiology must be determined.

Ten percent of children seen in the primary care setting show signs of growth failure. Children with FTT attain lower verbal intelligence, poorer language development, less developed reading skills, lower social maturity, and a higher incidence of behavioral disturbances.

Pathophysiology

Diagnostic Criteria for Failure to Thrive

A child younger than 2 years of age whose weight is below the 3rd or 5th percentile for age on more than one occasion.

A child younger than 2 years of age whose weight is less than 80% of the ideal weight for age.

A child younger than 2 years of age whose weight crosses two major percentiles downward on a standardized growth grid.

Exceptions to the previously noted criteria include the following:

Children of genetically short stature.

Small-for-gestational age infants.

Preterm infants.

"Overweight" infants whose rate of height gain increases while the rate of weight gain decreases.

Infants who are normally lean.

Many patients with FTT have either an organic or nonorganic cause; however, a sizable number of patients have both psychosocial and organic causes for their condition. FTT should be approached as a syndrome of malnutrition brought on by a combination of organic, behavioral, and environmental factors.

Clinical Evaluation of Poor Weight Gain or Weight Loss

Feeding history should assess details of breast or formula feeding, timing and introduction of solids, feeding advice already followed, who feeds the infant, position and placement of the infant for feeding, and stooling or vomiting patterns.

Developmental History should cover gestational and perinatal history, developmental milestones, infant temperament, and the infant's daily routine.

Psychosocial history should include family composition, employment status, financial status, stress, isolation, child-rearing beliefs, history of maternal depression, and the caretaker's own history of possible childhood abuse or neglect.

Family history should include heights, weights, illnesses, and development that may indicate constitutional short stature, inherited diseases, or developmental delay.

Causes of Inadequate Caloric Intake

Lack of Appetite

! Anemia (eg, iron deficiency)

! Psychosocial problems (eg, apathy)

! Central nervous system (CNS) pathology (eg, hydrocephalus, tumor)

! Chronic infection (eg, urinary tract infection, acquired immunodeficiency syndrome)

! Gastrointestinal disorder (eg, pain from reflux esophagitis)

Difficulty with Ingestion

! Psychosocial problems (eg, apathy, rumination)

! Cerebral palsy/CNS disorder (eg, hypertonia, hypotonia)

! Craniofacial anomalies (eg, choanal atresia, cleft lip and palate micrognathia, glossoptosis)

! Dyspnea (congenital heart disease, pulmonary disease)

! Feeding disorder

! Generalized muscle weakness/pathology (eg, myopathies)

! Tracheoesophageal fistula

! Genetic syndrome (eg, Smith-Lemli-Opitz-syndrome)

! Congenital syndrome (eg, fetal alcohol syndrome)

Unavailability of Food

! Inappropriate feeding technique

! Inadequate volume of food

! Inappropriate food for age

! Withholding of food (abuse, neglect, psychosocial)

Vomiting

! CNS pathology (increased intracranial pressure)

! Intestinal tract obstruction (eg, pyloric stenosis, malrotation)

! Gastroesophageal reflux

! Drugs (eg, syrup of ipecac)

Physical Examination

Height, weight, and head circumference should be plotted on a standard growth curve. Three measurements that are below the 3rd percentile indicate an underlying organic disease. If all three measurements are consistently below the 3rd percentile but show the same rate of increase over a period of time, there is a good chance that the infant had intrauterine growth retardation. If the child's median age for weight is less than the median age for height, the child may be undernourished.

Dysmorphic features and physical signs of central nervous system, pulmonary, cardiac, or gastrointestinal disorders, or signs of neglect or abuse (poor hygiene, unexplained bruises or scars, or inappropriate behavior) should be sought.

Observation of the Infant and Caretaker. While feeding and playing, the infant may avoid eye contact or withdraw from physical attention and may show a poor suck or swallow, or aversion to oral stimulation. Ineffective feeding technique or inappropriate response to the infant's physiologic or social cues may be displayed by the caretaker.

Diagnostic Testing

Laboratory testing should be guided by findings on the history and physical examination. Tests that will usually exclude an organic pathology include complete blood count, urinalysis, urine culture, blood urea nitrogen, creatinine, serum electrolyte levels, and a tuberculin test.

Radiologic Determination of Bone Age. If the bone age is normal, it is unlikely that the infant has a systemic chronic disease or a hormonal abnormality as the cause of poor weight gain.

Severe malnutrition requires measurement of albumin, alkaline phosphatase, calcium, and phosphorous to assess protein status and to look for biochemical rickets.

Human immunodeficiency virus screening, sweat test, or further radiologic examination are indicated if history and physical examination results indicate a diagnosis.

A feeding evaluation by a nutritionist or an occupational therapist may detect a subtle feeding disorder if findings on the history, physical examination, and laboratory evaluation do not yield a diagnosis.

Causes of Inadequate Calorie Absorption

Malabsorption

! Biliary atresia or cirrhosis

Celiac disease

! Cystic fibrosis

! Enzymatic deficiencies

Food (protein) sensitivity or intolerance

Immunologic deficiency

Inflammatory bowel disease

Diarrhea

Bacterial gastroenteritis

Parasitic infection

Hepatitis

Hirschsprung Disease

Refeeding diarrhea

 

Causes of Increased Calorie Requirements

Increased Metabolism/Increased Use of Calories

Chronic/recurrent infection (eg, urinary tract infection, tuberculosis)

Chronic respiratory insufficiency (eg, bronchopulmonary dysplasia)

Congenital heart disease/acquired heart disease

Malignancy

Chronic anemia

Toxins (lead)

Drugs (eg, excess levothyroxine)

Endocrine disorders (eg, hyperthyroidism, hyperaldosteronism)

Defective Use of Calories

Metabolic disorders (eg, aminoacidopathies, inborn errors of carbohydrate metabolism)

Renal tubular acidosis

Chronic hypoxemia (eg, cyanotic heart disease)

 

Treatment of Failure to Thrive

The normal, healthy infant requires an average of 100 kcal/kg of body weight per day. Nutritional requirements in children with FTT usually are 150 kcal/kg per day.

Treatment of Infants

The number of calories per ounce of formula can be increased by adding less water (13 oz infant formula concentrate mixed with 10 oz water provides 24 kcal/oz high-calorie formula) or by adding more carbohydrate in the form of glucose polymers or fat in the form of medium-chain triglycerides or corn oil.

Once nutritional recovery begins, the infant often demands and eats enough food to gain weight. At this point, ad libitum oral feedings are appropriate.

Treatment of Older Children. Foods can be fortified with such items as milk products, margarine, oil, and peanut butter.

For the infant or toddler who does not gain weight despite offered oral feedings, the diet should be supplemented by nasogastric tube feeding.

Parental Behavioral Advice

Try to relax; feeding/eating and meal times should be pleasant. Avoid battles over eating. Encourage the child, but avoid forced feeding or punitive approaches.

Use positive reinforcement (eg, praise for eating well). The withholding of food is not an appropriate form of punishment.

Accept your child's wish to feed himself. Accept that there will be a mess and be prepared (eg, newspaper on the floor).

Try to eat together as a family. Young children like to mimic the good eating behavior of older siblings and parents.

Allow about 1 hour without food or drink (except water) before a meal to stimulate the appetite.

Offer solids first and limit juices to 4 to 8 ounces per day. Consumption of excessive fluids reduces the intake of solid foods.

Establish a routine of meals and snacks at set times. Avoid snacks right after an unfinished meal.

Recognize your child's cues indicating hunger, satiety, and food preferences.

Limit possible distractions (eg, television) during meals.

Hospitalization is necessary when either outpatient management fails, the degree of malnutrition is severe, or the psychosocial circumstances put the infant at risk for harm.