Failure to thrive

Failure to thrive (FTT), more recently known as faltering weight or weight faltering,^[1] is a term used in pediatric medicine, as well as veterinary medicine (where it is also referred to as ill-thrift), to indicate insufficient weight gain or inappropriate weight loss. When not more precisely defined, the term refers to pediatric patients.^[1] In children, it is usually defined in terms of weight, and can be evaluated either by a low weight for the child's age, or by a low rate of increase in the weight.^[2]

The term ‘failure to thrive’ has been used vaguely and in different contexts to refer to different issues in pediatric growth.^[3] It is most commonly used to describe a failure to gain weight, but some providers have also used it to describe a failure to grow, or a failure to grow and to gain weight.^[3] As used by pediatricians, it covers poor physical growth of any cause.^[4] The term has been used in different ways,^[5] and different objective standards have been defined.^[6][7] FTT is suggested by a fall in one or more weight centile spaces on a World Health Organization (WHO) growth chart depending on birth weight or when weight is below the 2nd percentile of weight for age irrespective of birth weight.^[8][9] In children whose birth weight was between the 9th and 91st percentile FTT is indicated by a drop across 2 or more centile spaces.^[8] Weight loss after birth is normal and most babies return to their birth weight by 3 weeks of age.^[8] Clinical assessment for FTT is recommended for babies who lose more than 10% of their birth weight or do not return to their birth weight after 3 weeks.^[8]

History

FTT was first introduced in the early 20th century to describe poor growth in orphan children but became associated with negative implications (such as maternal deprivation) that often incorrectly explained the underlying issues.^[10] Throughout the 20th century, FTT was expanded to include many different issues related to poor growth, which made it broadly applicable but non-specific.^[10] The current conceptualization of FTT acknowledges the complexity of faltering growth in children and has shed many of the negative stereotypes that plagued previous definitions.^[10]

Presentation

Failure to thrive occurs in children whose nutritional intake is insufficient for supporting normal growth and weight gain.^[4][11][12] Failure to thrive typically presents before 2 years of age, when growth rates are highest.^[12] Parents may express concern about picky eating habits, poor weight gain, or smaller size compared relative to peers of similar age.^[11] Physicians often identify failure to thrive during routine office visits, when a child's growth parameters are not tracking appropriately on growth curves.^[11]

Etiologies

Traditionally, causes of FTT have been divided into endogenous and exogenous causes. These causes can be largely grouped into three categories: inadequate caloric intake, malabsorption/caloric retention defect, and increased metabolic demands.^[13] Initial investigation should consider prenatal history, postnatal history, past medical history, feeding history to assess overall caloric intake, developmental history, family history, and psychosocial history.^[4]

Endogenous (or "organic")

Causes are due to physical or mental issues with the child itself. It can include various inborn errors of metabolism. Problems with the gastrointestinal system such as excessive gas and acid reflux are painful conditions which may make the child unwilling to take in sufficient nutrition.^[13] Cystic fibrosis,^[8] diarrhea, liver disease, anemia or iron deficiency, and coeliac disease make it more difficult for the body to absorb nutrition.^[8][13] Other causes include physical deformities such as cleft palate and tongue tie. Milk allergies can cause endogenous FTT.^[4] Also the metabolism may be raised by parasites, asthma, urinary tract infections, and other fever-inducing infections, hyperthyroidism or congenital heart disease, so that it becomes difficult to get in sufficient calories to meet the higher caloric demands.^[13]

Exogenous (or "nonorganic")

Caused by caregiver's actions. Examples include physical inability to produce enough breastmilk,^[13] using only babies' cues to regulate breastfeeding so as to not offer a sufficient number of feeds (sleepy baby syndrome).^[14] A recent study on toddlers with exogenous FTT has found preliminary evidence suggesting that difficulty experienced during feeding times with this condition may in fact be impacted by preexisting sensory processing problems.^[15] Such difficulties with sensory processing are more commonly observed in toddlers who have a history of growth deficiency and feeding problems; however, further research is required in order to determine a causal relationship between sensory processing problems and nonorganic FTT.^[15] In developing countries, conflict settings and protracted emergencies, exogenous faltering may be caused by chronic food insecurity, lack of nutritional awareness, and other factors beyond the caregiver's control.^[16] As many as 90% of failure to thrive cases are non-organic.^[17]

Mixed

However, to think of the terms as dichotomous can be misleading, since both endogenous and exogenous factors may co-exist.^[12] For instance a child who is not getting sufficient nutrition may act content so that caregivers do not offer feedings of sufficient frequency or volume, and a child with severe acid reflux who appears to be in pain while eating may make a caregiver hesitant to offer sufficient feedings.^[12]

Differential Diagnosis by Etiology

Diagnosis

FTT may be evaluated through a multifaceted process, beginning with a patient history that notably includes diet history, which is a key element for identifying potential causes of FTT.^[3][22] Next, a complete physical examination may be done, with special attention being paid to identifying possible organic sources of FTT.^[3] This could include looking for dysmorphic features, abnormal breathing sounds, and signs of specific vitamin and mineral deficiencies.^[3] The physical exam may also reveal signs of possible child neglect or abuse.^[3] Based on the information gained from the history and physical examination, a workup can then be conducted, in which possible sources of FTT can be further probed, through blood work, X-rays, or other tests.^[3] Laboratory workup should be directed by concerning history and physical examination findings, as it is estimated that the usefulness of laboratory investigations for children with failure to thrive is 1.4%.^[4]

Treatment

Infants and children who have had unpleasant eating experiences (e.g. acid reflux or food intolerance) may be reluctant to eat their meals.^[22] Additionally, force feeding an infant or child can discourage proper self-feeding practices and in-turn cause undue stress on both the child and their parents.^[22] Psychosocial interventions can be targeted at encouraging the child to feed themselves during meals.^[8][22] Also, making mealtimes a positive, enjoyable experience through the use of positive reinforcement may improve eating habits in children who present with FTT.^[8][22] If behavioural issues persist and are affecting nutritional habits in children with FTT it is recommended that the child see a psychologist.^[22] If an underlying condition, such as inflammatory bowel disease, is identified as the cause of the child's failure to thrive then treatment is directed towards the underlying condition.^[4]

Prognosis

Children with failure to thrive are at an increased risk for long-term growth, cognitive, and behavioral complications.^[23] Studies have shown that children with failure to thrive during infancy were shorter and lower weight at school-age than their peers. Failure to thrive may also result in children not achieving their growth potential, as estimated by mid-parental height.^[23][24] Longitudinal studies have also demonstrated lower IQs (3-5 points) and poorer arithmetic performance in children with a history failure to thrive, compared to peers receiving adequate nutrition as infants and toddlers.^[17][25] Early intervention and restoration of adequate nutrition has been shown to reduce the likelihood of long-term sequelae, however, studies have shown that failure to thrive may cause persistent behavioral problems, despite appropriate treatment.^[23]

Epidemiology

Failure to thrive is a common presenting problem in the pediatric population. Failure to thrive is very prevalent in the United States, representing 5-10% of children seen as outpatients by primary care physicians.^[23] Failure to thrive is more prevalent in children of lower socioeconomic status.^[23] Failure to thrive accounts for 3-5% of all hospital admissions for children under two years of age.^[26][27] Retrospective studies suggest that males are slightly more likely than females to be admitted to the hospital for failure to thrive (53.2% vs. 46.7%).^[27]

See also

• Hospitalism
• Stunted growth

References