Understanding and Assessing 'Failure' to Thrive


Published: 19 May 2021

What is Failure to Thrive?

Failure to thrive (FTT), also known as faltering growth or poor growth, describes a pattern of poor weight gain in children (Starship 2019; PCH 2020).

Generally, this term applies to children under the age of two whose weight, or rate of weight gain, is considerably lower than what is expected for other children of the same age and gender (RCHM 2021; Ben-Barak 2020).

It is normal for children to experience periods of no growth. However, a child who is consistently falling behind what is considered typical may be failing to thrive (Ben-Barak 2020).

While there is currently no singular accepted measure of FTT, the best indicator is weight and length trending downwards accompanied by the age growth charts (RCHM 2015).

The World Health Organization's growth charts can be viewed here.

FTT is an umbrella term that describes a growth pattern - it is not a condition that is diagnosed (Ben-Barak 2020; Starship 2019).

Note: It is normal for newborns to lose up to 10% of their birth weight in the first few days of life. This weight is generally regained within three weeks once feeding has been established (Gonzalez-Viana et al. 2017).

failure to thrive weighing child
Generally, failure to thrive describes children under the age of two whose weight, or rate of weight gain, is considerably lower than what is expected

Causes of Failure to Thrive

FTT is complex and may be caused by a combination of factors (Gonzalez-Viana et al. 2017). In many cases, no specific cause can be identified (PCH 2020).

Generally, FTT occurs when a child is consuming or using less nutrition than they require (Ben-Barak 2020). This may be due to:

  • Medical causes, which impair the body’s ability to use food to grow and develop
  • Environmental causes, which prevent the child from being fed adequately
  • Behavioural causes, wherein the child is offered adequate food but does not consume enough.

(Ben-Barak 2020)

Medical causes
  • Health conditions such as:
    • Digestive system defects
    • Metabolic disorders
    • Cystic fibrosis
    • Coeliac disease
    • Diabetes
    • Inflammatory bowel disease
    • Severe asthma
    • Congenital heart disease
    • Hyperthyroidism
    • Renal failure
  • Issues that interfere with food intake or retention, such as:
    • Cleft lip/palate
    • Diarrhoea or vomiting
    • Gastro-oesophageal reflux
    • Reduced appetite
  • Food component allergies
  • Birth complications such as prematurity, low birth weight or pregnancy complications
  • Conditions that cause increased energy expenditure, such as:
    • Certain heart and respiratory conditions
    • Hormonal disorders
    • Nervous system disorders
    • Infection
  • Chromosomal disorders, such as Down syndrome
  • Perinatal disorders, such as fetal alcohol syndrome
Environmental causes
  • Poverty or homelessness
  • Parents lacking understanding of their child’s nutritional needs due to language barriers, intellectual disability, literacy or other factors
  • Lack of structure in eating habits (e.g. no set mealtimes)
  • Neglect, inexperience or inattention from the child’s parents
  • Unfounded parental concerns related to feeding, such as:
    • Worrying that the child is overweight
    • Unnecessary dietary restrictions
    • Perceived food allergies
  • Breastfeeding difficulties
  • Parental mood disorder, disability or chronic illness
  • Restricted diet, for example
    • Vegan diet
    • Restricted food groups
    • Sensory aversions to certain foods
  • Parental error in preparing feeding formula
  • Early or delayed introduction of solids to the child’s diet
  • Coercive feeding
  • Social isolation
  • Failure to attend medical appointments
  • Family violence
  • Trauma
  • Involvement of child protection services
Behavioural causes
  • Refusing food
  • Eating disorders
  • Mood disorders

(RCHM 2021; Ben-Barak 2020; Matthai 2019)

Interestingly, most cases of FTT (up to 80%) appear to be caused by environmental factors rather than medical conditions (Raab 2021).

Supporting the Parents of Children With Failure to Thrive

It is important to note that neglect is not usually the cause of FTT. Parents of children who are failing to thrive are often made to feel responsible for their child’s slow growth, so providing appropriate emotional support to the child’s parents is an integral part of the healthcare professional’s role (Gonzalez-Viana et al. 2017).

As Spencer (2007) notes, investigating FTT is not a neutral process and has the potential to do more harm than good by generating anxiety. Furthermore, it can cause parents to feel frustrated and guilty that they have been perceived as unable to properly nurture their child (Raab 2021).

As feeding and growth can be highly sensitive parenting topics, it is crucial to avoid instilling unnecessary anxiety and guilt in parents (RCHM 2015).

Instead, parents should be actively engaged with and involved in the investigation process (Raab 2021). Ensure that you:

  • Encourage parents to visit often and for long periods of time (if the child has been admitted to hospital)
  • Make parents feel welcome
  • Support the parents’ attempts to feed their child
  • Encourage parent-child play by providing toys.

(Raab 2021)

Symptoms of Failure to Thrive

failure to thrive baby head circumference

Note that FTT is often a gradual process and may therefore be difficult to recognise (Ben-Barak 2020).

While there is no single definition of FTT, potential signs include:

  • Weight, length and/or head circumference being well below standard growth measurements for the child’s age
  • Very slow or a complete lack of growth.

(Ben-Barak 2020)

Additional symptoms may include:

  • Fatigue
  • Irritability
  • Constipation
  • Failing to meet developmental milestones.

(Ben-Barak 2020)

Complications of Failure to Thrive

Poor growth during childhood may lead to health and development issues such as:

  • Altered body composition
  • Altered growth potential
  • Impaired learning and development
  • Behavioural issues
  • Eating issues (e.g. slowness or pickiness)
  • Elimination issues.

(RCHM 2015; Raab 2021)

How is Failure to Thrive Assessed?

Assessing the Child’s History

The healthcare professional should take into account:

  • The child’s intake:
    • Whether the child is breastfed or bottle-fed
    • The amount and duration of feeds within a 24 hour period
    • Breast milk supply/formula preparation
    • The age at which solid foods were introduced
    • The composition of solid foods consumed
    • The number and quantity of snacks and meals consumed
    • (For toddlers) Milk intake within a 24 hour period
    • Gestational age at birth and birth weight
  • The child’s output:
    • Losses such as vomiting, stools, urine and others (e.g. stoma)
    • Triggers that may lead to increased output (e.g. certain foods)
  • The child’s food behaviour and dietary practices:
    • Whether the child is accepting of food or needs to be coerced/distracted
    • Set-up and duration of mealtime
    • Whether the child has any dietary restrictions
  • The child’s past history:
    • Whether the child has a chronic or current illness, or recurrent infection
    • The child's immunisations status
  • Family growth:
    • The pattern of weight gain and growth in the child’s relatives
    • Mid-parental height
  • Psychosocial assessment of the family in order to identify any signs of family vulnerability
  • Whether the child is at increased risk of FTT (see above)
  • Recent or concurrent illness (e.g. infections, severe asthma, eczema)
  • The child’s social history, including:
    • Parental mental illness
    • Lack of financial resources for food requirements
    • Unsuitable housing
    • Lack of family or community support
    • Whether the child is a refugee or recent immigrant
    • Failure to attend hospital or community services appointments
    • History of child protection involvement
  • Medicines being taken by the child.

(RCHM 2021; WCH 2014; Queensland Health 2017)

Examination of the Child

The healthcare professional should assess the following:

  • The child’s overall appearance; do they look well and in proportion?
  • Hydration status
  • Signs of underlying systemic illness
  • Growth pattern (by plotting serial measures of weight, height and head circumference)
    • Any changes in growth trajectory and the circumstances surrounding these changes (e.g. introduction of solid foods)
  • Mid-parental height
  • Muscle bulk (i.e. buttocks), subcutaneous fat stores (i.e. thighs), skin, hair, gums, eyes and nails
  • Developmental level
  • Interactions between the child and their caregiver
  • Any signs of abuse or neglect
  • The child’s feed, if possible.

(RCHM 2021)

failure to thrive examination of the child

Additional Investigations

Generally, if the child appears well, is developing normally and has normal findings from clinical examination and initial investigations, there is no cause for concern (PCH 2020).

However, in some cases, the child may need to undergo additional screening investigations if their history or examination suggests a particular diagnosis. Possible investigations that may be considered include:

  • Urine tests: urinalysis, microscopy and culture
  • Blood tests:
    • FBE, ferritin, UEC, TSH, glucose and LFT
    • Coeliac serology and total IgA (if the child is consuming solids or feed containing gluten)
    • Micronutrients, particularly active B12 (if malabsorption or restricted dietary intake is suspected)
  • Stool tests: microscopy, fat globules and fatty acid crystals
  • ESR and faecal calprotectin testing (in children over 12 months of age)
  • Specific screening for metabolic, immune or genetic issues (if required).

(RCHM 2021)

Failure to Thrive Management

Management of FTT should involve an interprofessional team, which may comprise:

  • Child health nurses or lactation consultants
  • General practitioners
  • Paediatricians
  • Dieticians
  • Speech pathologists
  • Interprofessional feeding clinic
  • Psychologists
  • Infant mental health clinicians
  • Social worker or child protection services.

(RCHM 2021)

Treatment will depend on specific underlying factors. Most children can be managed as outpatients, however, those displaying red flags may require consultation with a paediatric team (RCHM 2021).

Red flags include:

  • Severe malnutrition, illness or dehydration
  • Failure to manage the child as an outpatient
  • Suspected parental abuse or neglect
  • Severe parental mental health concerns.

(RCHM 2021)

Additional Resources


Test Your Knowledge

Question 1 of 3

True or false: Most incidences of failure to thrive are associated with neglect.


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