Failure to thrive (FTT), more recently known as faltering weight or weight faltering, is a term used in pediatric and adult 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. 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.
As used by pediatricians, it covers poor physical growth of any cause and does not itself imply abnormal intellectual, social, or emotional development, although it can subsequently be a cause of such pathologies. The term has been used in different ways, and different objective standards have been defined. Many definitions use the 5th percentile as a cutoff.
Traditionally, causes of FTT have been divided into endogenous and exogenous causes. Initial investigation should consider physical causes, calorie intake and psychosocial assessment.
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 gas and acid reflux are painful conditions which may make the child unwilling to take in sufficient nutrition.
Cystic fibrosis,
diarrhea,
liver disease, and celiac disease make it more difficult for the body to absorb nutrition. Other causes include physical deformities such as cleft palate and tongue tie. Milk allergies can cause endogenous FTT. Also the metabolism may be raised by parasites,
asthma,
urinary tract infections, and other fever-inducing infections, or heart disease so that it becomes difficult to get in sufficient calories to meet the higher caloric demands.
Exogenous (or "nonorganic")Caused by caregiver's actions. Examples include physical inability to produce enough breastmilk, using only babies' cues to regulate breastfeeding so as to not offer a sufficient number of feeds (sleepy baby syndrome), inability to procure formula when needed, purposely limiting total caloric intake (often for what the caregiver views as a more aesthetically pleasing child), and not offering sufficient age-appropriate solid foods for babies and toddlers over the age of six months. 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. 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. 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.
MixedHowever, to think of the terms as dichotomous can be misleading, since both endogenous and exogenous factors may co-exist. 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.
The term "failure to thrive" is also applied to geriatrics or more generally in adult medicine as a descriptive, non-specific term that encompasses "not doing well". Manifestations of this condition include weight loss, decreased appetite, poor nutrition, and inactivity. Four syndromes are prevalent and predictive of adverse outcomes in patients with failure to thrive: impaired physical function, malnutrition, depression, and cognitive impairment.
