Etiology of Failure to Thrive
The physiologic basis for failure to thrive (FTT) of any etiology is inadequate nutrition Overview of Undernutrition Undernutrition is a form of malnutrition. (Malnutrition also includes overnutrition.) Undernutrition can result from inadequate ingestion of nutrients, malabsorption, impaired metabolism, loss... read more and is divided into
Most cases of FTT are mixed.
Growth failure is due to an acute or chronic disorder that interferes with nutrient intake, absorption, metabolism, or excretion or that increases energy requirements ( see Table: Some Causes of Organic Failure to Thrive Some Causes of Organic Failure to Thrive ). Illness of any organ system can be a cause.
Nonorganic FTT is due to insufficient calorie intake. It usually manifests as failure to gain weight. Growth in length and head circumference remain normal for a period of time until they too become impacted by poor calorie intake. This is the most common pattern of nonorganic FTT.
Psychosocial FTT is a phenomenon in which growth failure accompanies or precedes poor weight gain. This is thought to occur because mental stress in the child may cause increased levels of counter-regulatory hormones (eg, corticosteroids, catecholamines), which oppose the effects of growth hormone.
Up to 80% of children with growth failure do not have an apparent growth-inhibiting (organic) disorder; growth failure occurs because of environmental neglect (eg, lack of food), stimulus deprivation, or both.
Lack of food may be due to
Poor understanding of feeding techniques
Improperly prepared formula (eg, overdiluting formula to stretch it because of financial difficulties)
Inadequate supply of breast milk (eg, because the mother is under stress, exhausted, or poorly nourished)
Nonorganic FTT is often a complex of disordered interaction between a child and caregiver. In some cases, the psychologic basis of nonorganic FTT seems similar to that of hospitalism, a syndrome observed in infants who have depression secondary to stimulus deprivation. The unstimulated child becomes depressed, apathetic, and ultimately anorexic. Stimulation may be lacking because the caregiver
Is depressed or apathetic
Has poor parenting skills
Is anxious about or unfulfilled by the caregiver role
Feels hostile toward the child
Is responding to real or perceived external stresses (eg, demands of other children in large or chaotic families, marital dysfunction, a significant loss, financial difficulties)
Poor caregiving does not fully account for all cases of nonorganic FTT. The child’s temperament, capacities, and responses help shape caregiver nurturance patterns. Common scenarios involve parent-child mismatches, in which the child’s demands (eg, a difficult feeder), although not pathologic, cannot be adequately met by the parents, who might, however, do well with a child who has different needs or even with the same child under different circumstances. A difficult feeder may uncover a problem with parent-child interaction that would have remained hidden if the child were an easy feeder.
In mixed FTT, organic and nonorganic causes can overlap. For example, children with organic disorders also have disturbed environments or dysfunctional parental interactions. Likewise, children with severe undernutrition caused by nonorganic FTT can develop organic medical problems.
Diagnosis of Failure to Thrive
Frequent weight monitoring
Thorough medical, family, and social history
Children with organic FTT may present at any age depending on the underlying disorder. Most children with nonorganic FTT manifest growth failure before age 1 year and many by age 6 months. Age should be plotted against weight, height, and head size on growth standards and growth charts, such as those recommended by the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC). (For children 0 to 2 years, see WHO Growth Charts; for children 2 years and older, see CDC Growth Charts.) Until premature infants reach 2 years of age, age should be corrected for gestation.
Weight is the most sensitive indicator of nutritional status. When FTT is due to inadequate caloric intake, weight falls from the baseline percentile before length does. Reduced linear growth usually indicates severe, prolonged undernutrition. Simultaneous fall off of length or height and weight suggests a primary disorder of growth or a prolonged inflammatory state. Because the brain is preferentially spared in protein-energy undernutrition Protein-Energy Undernutrition (PEU) Protein-energy undernutrition (PEU), previously called protein-energy malnutrition, is an energy deficit due to deficiency of all macronutrients. It commonly includes deficiencies of many micronutrients... read more , reduced growth in head circumference occurs late and indicates very severe or long-standing undernutrition. Children who are underweight may be smaller and shorter than their peers and may present with fussiness or crying, lethargy or sleepiness, and constipation Evaluation Constipation is responsible for up to 5% of pediatric office visits. It is defined as delay or difficulty in defecation. Normal frequency and consistency of stool varies with children's age... read more . FTT is associated with physical delays (eg, sitting, walking), social delays (eg, interacting, learning), and, if occurring in older children, delayed puberty Delayed Puberty Delayed puberty is absence of sexual maturation at the expected time. Diagnosis is by measurement of gonadal hormones (testosterone and/or estradiol), luteinizing hormone, and follicle-stimulating... read more .
Usually, when growth failure is noted, a history (including diet history— see Table: Essentials of the History for Failure to Thrive Essentials of the History for Failure to Thrive ) is obtained, diet counseling is provided, and the child’s weight is monitored frequently. A child who does not gain weight satisfactorily in spite of outpatient assessment and intervention usually is admitted to the hospital so that all necessary observations can be made and diagnostic tests can be done quickly. Careful examination of the growth chart can lend clues to the diagnosis. For example, if the weight and height fall off simultaneously, a diagnosis of an organic disease is likely.
Without historic or physical evidence of a specific underlying etiology for growth failure, no single clinical feature or test can reliably distinguish organic from nonorganic FTT. Because children may have both organic and nonorganic FTT, the physician should search simultaneously for an underlying physical problem and for personal, family, and child-family characteristics that support a psychosocial etiology. Optimally, evaluation is multidisciplinary, involving a physician, a nurse, a social worker, a nutritionist, an expert in child development, and often a psychiatrist or psychologist. The child’s feeding behaviors with health care practitioners and with the parents must be observed, whether the setting is inpatient or outpatient.
Engaging the parents as co-investigators is essential. It helps foster their self-esteem and avoids blaming parents who may already feel frustrated or guilty because of a perceived inability to nurture their child. The family should be encouraged to visit as often and as long as possible. Staff members should make them feel welcome, support their attempts to feed the child, and provide toys and ideas that promote parent-child play and other interactions.
Parental adequacy and sense of responsibility should be evaluated. Suspected neglect or abuse must be reported to social services, but in many instances, referral for preventive services that are targeted to meet the family’s needs for support and education (eg, additional food stamps, more accessible child care, parenting classes) is more appropriate.
During hospitalization, the child’s interaction with people in the environment is closely observed, and evidence of self-stimulatory behaviors (eg, rocking, head banging) is noted. Some children with nonorganic FTT have been described as hypervigilant and wary of close contact with people, preferring interactions with inanimate objects if they interact at all. Although nonorganic FTT is more consistent with neglectful than abusive parenting, the child should be examined closely for evidence of abuse Symptoms and Signs Child maltreatment is behavior toward a child that is outside the norms of conduct and entails substantial risk of causing physical or emotional harm. Four types of maltreatment are generally... read more . A screening test of developmental level should be done and, if indicated, followed with more sophisticated assessment. Hospitalized children who begin gaining weight well with proper feeding techniques, formula preparation, and amount of calories are more likely to have nonorganic FTT.
Extensive laboratory testing is usually nonproductive. If a thorough history or physical examination does not indicate a particular cause, most experts recommend limiting screening tests to
Complete blood count with differential
Erythrocyte sedimentation rate
Blood urea nitrogen and serum creatinine and electrolyte levels
Urinalysis (including ability to concentrate and acidify) and culture
Stool for pH, reducing substances, odor, color, consistency, and fat content
Depending on prevalence of specific disorders in the community, blood lead level, HIV, or tuberculosis testing may be warranted.
Other tests that are sometimes appropriate include levels of thyroxine (T4) and thyroid-stimulating hormone (TSH). Growth hormone assessment Diagnosis Growth hormone deficiency is the most common pituitary hormone deficiency in children and can be isolated or accompanied by deficiency of other pituitary hormones. Growth hormone deficiency... read more (done by measuring fasting blood levels of insulin-like growth factor 1 [IGF-1] and IGF binding protein type 3 [IGFBP-3]) is appropriate when growth in height is more severely affected than growth in weight or when height/length and weight fall off simultaneously . Additionally, even though newborn screening tests now assess newborns for cystic fibrosis, a sweat test should be done if the child has a history of recurrent upper or lower respiratory tract disease, a ravenous appetite, foul-smelling bulky stools, hepatomegaly, or a family history of cystic fibrosis. Newborn screening test results should be reviewed for indications of other genetic diseases.
Investigation for infectious diseases should be reserved for children with evidence of infection (eg, fever, vomiting, cough, diarrhea); however, a urine culture may be helpful because some children with FTT due to urinary tract infection lack other symptoms and signs.
Radiologic investigation should be reserved for children with evidence of anatomic or functional pathology (eg, pyloric stenosis, gastroesophageal reflux). However, if an endocrine cause is suspected, bone age is sometimes determined.
Prognosis for Failure to Thrive
Prognosis with organic FTT depends on the cause.
With nonorganic FTT, the majority of children age > 1 year achieve a stable weight above the 3rd percentile. Children who develop FTT before age 1 year are at high risk of cognitive delay, especially verbal and math skills. Children diagnosed at age < 6 months, when the rate of postnatal brain growth is maximal, are at highest risk. General behavioral problems, identified by teachers or mental health practitioners, occur in about 50% of children. Problems specifically related to eating (eg, pickiness, slowness) or elimination tend to occur in a similar proportion of children, usually those with other behavioral or personality disturbances.
Treatment of Failure to Thrive
Treatment of underlying disorder
Long-term social support
Treatment of failure to thrive is aimed at providing sufficient health and environmental resources to promote satisfactory growth. A nutritious diet containing adequate calories for catch-up growth (about 150% of normal caloric requirement) and individualized medical and social supports are usually necessary. Ability to gain weight in the hospital does not always differentiate infants with nonorganic FTT from those with organic FTT; all children grow when given sufficient nutrition. However, some children with nonorganic FTT lose weight in the hospital, highlighting the complexity of this condition.
For children with organic or mixed FTT, the underlying disorder should be treated quickly. For children with apparent nonorganic FTT or mixed FTT, management includes provision of education and emotional support to correct problems interfering with the parent-child relationship. Because long-term social support or psychiatric treatment is often required, the evaluation team may be able only to define the family’s needs, provide initial instruction and support, and institute appropriate referrals to community agencies. The parents should understand why the referrals are being made and, if options exist, should participate in decisions concerning which agencies will be involved. If the child is hospitalized in a tertiary care center, the referring physician should be consulted regarding local agencies and the level of expertise available in the community.
A predischarge planning conference involving hospital-based personnel, representatives from the community agencies that will provide follow-up services, and the child’s primary physician is ideal. Areas of responsibility and lines of accountability must be clearly defined, preferably in writing, and distributed to everyone involved. The parents should be invited to a summary session after the conference so that they can meet the community workers, ask questions, and arrange follow-up appointments.
In some cases, the child must be placed in foster care. If the child is expected to eventually return to the biologic parents, parenting skill training and psychologic counseling must be provided for them. Their child’s progress must be monitored scrupulously. Return to the biologic parents should be based on the parents’ demonstrated ability to care for the child adequately, not only on the passage of time.
Failure to thrive (FTT) should be suspected in children with a significant drop in percentile rank on growth parameters, a consistently low percentile rank (eg, below 3rd to 5th percentile).
Organic FTT is due to a medical disorder (eg, malabsorption, inborn error of metabolism).
Nonorganic FTT is due to psychosocial problems (eg, neglect, poverty, difficult parent-child interactions).
In addition to taking a thorough medical, social, and dietary history, health care providers should observe parents/caregivers feeding the child.
Hospitalization may be necessary to evaluate the child, to observe the child's response to appropriate feeding, and to involve a feeding team if needed.
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