Failure to thrive

Failure to thrive, also known as weight faltering or faltering growth, indicates insufficient weight gain or absence of appropriate physical growth in children. FTT 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.
The term "failure to thrive" has been used in different ways, as no single objective standard or universally accepted definition exists for when to diagnose FTT. One definition describes FTT as a fall in one or more weight centile spaces on a World Health Organization growth chart depending on birth weight or when weight is below the 2nd percentile of weight for age irrespective of birth weight. Another definition of FTT is a weight for age that is consistently below the fifth percentile or weight for age that falls by at least two major percentile lines on a growth chart. While weight loss after birth is normal and most babies return to their birth weight by three weeks of age, 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 three weeks. Failure to thrive is not a specific disease, but a sign of inadequate weight gain.
In veterinary medicine, FTT is also referred to as ill-thrift.

Signs and symptoms

Failure to thrive is most commonly diagnosed before two years of age, when growth rates are highest, though it can present among children and adolescents of any age. Caretakers may express concern about poor weight gain or smaller size compared to peers of a similar age. Physicians often identify FTT during routine office visits, when a child's growth parameters such as height and weight are not increasing appropriately on growth curves. Other signs and symptoms may vary widely depending on the etiology of FTT. Differentiating stunting from wasting is important, as they can indicate different causes of FTT. "Wasting" refers to a deceleration in stature more than two standard deviations from median weight-for-height, whereas "stunting" is a drop of more than two standard deviations from the median height-for-age.
The characteristic pattern seen with children with inadequate nutritional intake is an initial deceleration in weight gain, followed several weeks to months later by a deceleration in stature, and finally a deceleration in head circumference. Inadequate caloric intake could be caused by lack of access to food, or caretakers may notice picky eating habits, low appetite, or food refusal. FTT caused by malnutrition could also yield physical findings that indicate potential vitamin and mineral deficiencies, such as scaling skin, spoon-shaped nails, cheilosis, or neuropathy. Lack of food intake by a child could also be due to psychosocial factors related to the child or family. Screening patients and their caretakers for psychiatric conditions such as depression or anxiety is vital, as well as for signs and symptoms of child abuse, neglect, or emotional deprivation.
Children who have FTT caused by a genetic or medical problem may have differences in growth patterns compared to children with FTT due to inadequate food intake. A decrease in length with a proportional drop in weight can be related to long-standing nutritional factors or genetic or endocrine causes. Head circumference, as well, can be an indicator for the etiology of FTT. If head circumference is affected initially in addition to weight or length, other factors are more likely causes than inadequate intake. Some of these include intrauterine infection, teratogens, and some congenital syndromes.
Children who have a medical condition causing FTT may have additional signs and symptoms specific to their condition. Fetal alcohol syndrome has been associated with FTT, and can present with characteristic findings including microcephaly, short palpebral fissures, a smooth philtrum and a thin vermillion border. Disorders that cause difficulties absorbing or digesting nutrients, such as Crohn's disease, cystic fibrosis, or celiac disease, can present with abdominal symptoms. Symptoms can include abdominal pain, abdominal distention, hyperactive bowel sounds, bloody stools, or diarrhea.

Cause

Traditionally, causes of FTT have been divided into endogenous and exogenous causes, which can also be largely grouped into three categories - inadequate caloric intake, malabsorption/caloric retention defect, and increased metabolic demands.
; Endogenous :Endogenous causes are due to physical or mental issues affecting the child. These causes 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. Cystic fibrosis, diarrhea, liver disease, anemia or iron deficiency, Crohn's disease, and coeliac disease make it more difficult for the body to absorb nutrition. Other causes include physical deformities such as cleft palate and tongue tie that impede food intake. Additionally, allergies such as milk allergies can cause endogenous FTT. FAS has also been associated with failure to thrive. Additional, medical conditions including parasite infections, urinary tract infections, other fever-inducing infections, asthma, hyperthyroidism and congenital heart disease may raise energy needs of the body and cause greater difficulty taking in sufficient calories to meet the higher caloric demands, leading to FTT.
; Exogenous : Exogenous causes are due to caregiver actions, whether unintentional or intentional. Examples include physical inability to produce enough breastmilk, inappropriate feeding schedules or feeding technique, and mistakes made in formula preparation. In developing countries, conflict settings, and protracted emergencies, exogenous FTT may more commonly be caused by chronic food insecurity, lack of nutritional awareness, and other factors beyond the caregiver's control. As many as 90% of failure to thrive cases are non-organic.
; Mixed: Both endogenous and exogenous factors may co-exist. For instance, a child who is not getting sufficient nutrition for endogenous reasons may act content so that caregivers do not offer feedings of sufficient frequency or volume. Yet, a child with severe acid reflux who appears to be in pain while eating may also make a caregiver hesitant to offer sufficient feedings.

Inadequate caloric intake

Inadequate caloric intake indicates that an insufficient amount of food and nutrition is entering the body, whether due to lack of food, anatomical differences causing difficulty eating, or psychosocial reasons for decreased food intake.

Cause	Description/presentation	Mechanism	Epidemiology
Poverty/inadequate food supply	Inadequate food available for child	Decreased food intake	Most common cause of failure to thrive globally
Inadequate breast milk supply/ineffective latching	Mother is unable to produce enough breast milk or infant is unable to latch properly during breastfeeding	Insufficient breastfeeding
Improper preparation of formula	Formula is not prepared or mixed properly	Insufficient nutrition from formula feeding
Postpartum depression/maternal depression	Mother experiences low mood, persistent sadness, and/or loss of interest or pleasure in activities	Mothers with depression are more likely to have breastfeeding difficulties and may have decreased desire to interact with their children, which may lead to decreased feeding	1 in 10 women in the US experience symptoms of depression 1 in 8 women experience symptoms of postpartum depression, or depression after childbirth
Child neglect	Caretakers fail to provide adequate care to the child	Caretakers do not adequately feed the child	Prevalence of neglect in non-organic FTT may be as high as 5-10%
Cerebral palsy	Disturbance in the developing fetal or infant brain leads to difficulties and delays in cognition, motor movement and coordination, and other aspects of development	Decreased motor function and coordination leads to difficulty feeding	Affects about 3.6/1000 children
Cleft lip/cleft palate	During fetal development, parts of the mouth/lips do not fuse properly, causing an anatomical defect	Impaired oral motor coordination and poor suck causes difficulty feeding	Occurs in about 1 in 600 to 800 live births
Gastroesophageal reflux disease	Regurgitation of food causes discomfort and irritability	Discomfort and pain after eating may cause poor appetite or refusal to feed	Occurrence peaks at about 4 months of age
Pyloric stenosis	Abnormal thickening of the opening between the stomach and small intestine blocks food from flowing through the gastrointestinal tract, causing projectile vomiting	Projectile vomiting after eating and inability of food to enter small intestine leads to dehydration and weight loss	Infant is usually well at birth, and pyloric stenosis usually presents at 3–6 weeks of age
Toxins causing gastrointestinal problems	Toxins such as lead can cause decreased appetite, constipation, or abdominal pain	Gastrointestinal problems and discomfort can lead to decreased appetite or refusal to eat
Avoidant/restrictive food intake disorder	Psychiatric condition in which individuals avoid eating certain foods or restrict the amount of food they eat; may be due to sensory sensitivity, a traumatic experience with eating, or another cause	Food avoidance or restriction leads to inadequate nutritional intake	-