Weight faltering and failure to thrive

Advice on helping parents to manage feeding difficulties, excluding medical problems and when to refer.

Weight faltering is common in babies and toddlers and occurs across all socio-economic groups, often causing concern for parents and professionals.

Although population studies indicate that the prognosis is generally good, the perception persists that poor weight gain causes long-term damage to the child.

This can cause anxiety for parents which may be damaging in itself. Families can enter a vicious cycle where feeding becomes stressful and mealtimes become so unpleasant that aversion to food occurs.

An organic cause is found in a minority of cases. Neglect or abuse can be a factor, although this is far less common than previously thought.

The key to management is to identify any medical problems that are causing or compounding poor weight gain, and to help parents manage eating difficulties, which are extremely common. It is essential to accurately chart weight, height and head circumference measurements. Often the only action taken is to frequently monitor weight and this can contribute to parental anxiety.


'Weight faltering' is the preferred term. 'Failure to thrive' is best reserved for those cases where there is not only poor weight gain but also a failure in psychosocial and emotional development — some argue that the term should only be used where abuse or neglect are clearly identified as a cause.

Because one in six infants cross centiles in their first year, interpretation of growth patterns takes some skill. Criteria for growth patterns that merit assessment include a sustained fall through two centile spaces, height and weight below the second percentile, or a discrepancy of more than two centiles between height and weight.

Babies and toddlers

Accurate measurements of weight, height and head circumference need to be plotted on an appropriate growth chart.

Babies born before 37 weeks gestation will be corrected for up to 12 months of age.

Medical problems are an uncommon cause, but it is important to exclude them early on because it is difficult to provide effective input if there are anxieties about an underlying medical problem.

Examination and assessment

A full examination is needed, including any dysmorphic signs and a neurodevelopmental assessment.

An important part of the assessment involves observing the child-parent interaction and sympathetically gaining an idea of diet and eating difficulties. Detailed recall of food eaten through the day should elicit whether nutrient intake is sufficient, whether there is a structured pattern to meals and whether the child is aversive to eating. It may also be helpful to ask the family to keep a diet diary for at least three days.

Children often have unnecessary investigations in the pursuit of a diagnosis. An FBC is helpful, however, because toddlers often have a poor intake of iron-rich foods, especially where eating difficulties exist, making iron deficiency common.

On examination, wasting of the muscle bulk, a poor complexion, thin wispy hair and developmental delay are indications that health may be at risk.

Common conditions associated with, or responsible for, poor weight gain are shown in the box below.


Once a medical diagnosis has been excluded the aim is to try to resolve any eating difficulties. Advice often focuses just on increasing calorie intake. It is also useful to ask a health visitor to observe a mealtime.

This can provide valuable information as a basis for advice and reassurance. A positive approach is to encourage parents to make mealtimes an enjoyable experience rather than focus on food.

When to refer

Children merit a paediatric referral when there are signs of an organic problem, such as diarrhoea, vomiting, pallor, persistent respiratory symptoms, dysmorphic signs, congenital abnormalities or developmental delay.

Referral routes for additional support include involving social services where there are social concerns or suspicion of neglect or abuse, speech therapy if there are concerns about oromotor skills, dietetics to aid with calorie intake, and a specialist nutrition team in areas where they exist.

Advising that the child attend nursery may be helpful as it provides support to the carer, a peer group to model eating behaviour and structured mealtimes.

The critical factors for a positive outcome are an early thorough evaluation to exclude medical problems, and the identification of health, family and social factors that have contributed to the development of weight faltering.

Causes of weight or growth faltering

Inadequate intake

  • Insufficient calories
  • Loss of calories - vomiting or gastro-oesophageal reflux
  • Aversion to eating - oesophagitis
  • Delayed oromotor development - problems with chewing and swallowing lumpy food
  • Behavioural eating difficulties - food refusal, fussiness, distraction

Problems with absorption

  • Intolerance of cow's milk protein
  • Coeliac disease

Metabolic problems

  • Chronic disease
  • Congenital heart disease
  • Congenital hypothyroidism

Reduced growth potential

  • Intrauterine growth retardation/low birth weight
  • Familial short stature

Underlying syndrome

  • Neurodevelopmental syndromes
  • Turner's syndrome
  • Fetal alcohol syndrome
  • Prader-Willi syndrome

Dr Kathryn Deakin is consultant paediatrician at Pinderfields General Hospital, West Yorkshire. Professor Mary Rudolf is consultant paediatrician and professor of child health at University of Leeds

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Further reading

  1. Batchelor J, Kerslake A. Failure to Find Failure to Thrive. London: Whiting & Birch. 1990.
  2. Khan F, Rudolf MCJ. Failure to thrive: Recognition and Management in Primary Care. Practical Paediatric Problems in Primary Care. Oxford: Oxford University Press. 2007: 135-48.
  3. Rudolf MCJ, Logan S. What is the longterm outcome for children who fail to thrive?: a systematic review. Arch Dis Child 2005; 90: 925-31.

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