Failure to thrive


These guidelines have been produced to guide clinical decision making for general practitioners (GPs). They are not strict protocols. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline.


Failure to thrive (also referred to as “faltering growth”, “poor growth” or “weight faltering”) refers to failure to gain weight appropriately.

There are differing definitions including:

  • weight persistently below the 2nd percentile
  • weight for length <10th percentile
  • rate of weight change that causes a decrease of two or more percentiles over time.1

In severe cases, ongoing severe malnutrition impairs overall growth; impacting weight first, then length and head circumference.2 Malnutrition categories can be defined by calculating Z-scores (see below).3 Failure to thrive occurs when caloric intake is insufficient to maintain growth and may be symptomatic of underlying disease or be indicative of psychosocial or environmental factors.1,4

Growth requirements change with age with the highest expected weight gain per day occurring in the first three months of life.1

Risk factors for failure to thrive include1:

  • prematurity
  • developmental delay
  • congenital or genetic anomalies
  • intrauterine exposures
  • medical conditions that cause inadequate intake
  • increased metabolic rate
  • malabsorption.

Psychosocial risk factors include 1,4:

  • social isolation
  • disordered feeding techniques
  • substance abuse
  • household violence/abuse
  • poverty.

Pre-referral screening

When plotting growth:

  • Use WHO charts for children < 2 years of age (see useful resources below)
  • Use corrected age when plotting growth for preterm (<37 weeks) infants
  • Use CDC charts for children > 2 years of age (see useful resources below)
  • Using Z-scores is beneficial, particularly if longitudinal declines have been noted.3
    • Use PediTools calculator to calculate percentiles/Z-score.
  • Use specialised growth charts for children with specific diagnoses such as Trisomy 21.
  • Review feeding mode (breast feeding or formula feeding) and the amount, bowels, development, newborn screen (Guthrie), social history and neonatal/general examination including airway/swallowing concerns.

Pre-referral management

  • For breastfed neonates/infants, consider lactation nurse review (see useful resources below)
  • Ensure correct formula preparation for formula-fed infants
  • Consider community dietitian assessment to check if child is receiving adequate calories.
  • After twelve months of age, limit cow’s milk to <500ml/day and offer solids prior to any milk feeds.
  • Cease juice/soft drink consumption. Recommend meals/snacks at appropriate frequency for child’s age with meals in a developmentally appropriate location (e.g. highchair).
  • Correct micronutrient deficiencies if identified.

Pre-referral investigations


  • Urine MC+S
  • Stool MC+S
  • Full blood picture
  • Iron studies
  • Thyroid function tests
  • Liver/renal function
  • B12/folate and vitamin D/bone biochemistry should be considered in at risk populations (e.g. vegetarian/vegan or maternal deficiencies in breastfeeding infants).
  • For older infants/children consuming gluten, add coeliac serology in addition to the above.

When to refer

  • Receiving adequate calories but ongoing poor growth
  • Abnormal screening investigations
  • Unable to improve calorie intake with dietetic intervention.

If severe abnormalities on physical examination (e.g. neurological abnormality, syndromic features, hypotonia) or significant psychosocial risk factors please discuss with general paediatric team on call and place urgent referral.

How to refer

  • Routine non-urgent referrals from a GP or a Consultant should go to the Central Referral Service.
  • Routine non-urgent referrals from private hospitals go to the PCH Referral Office (Fax: 6456 0097 or email
  • Urgent referrals (less than seven days) go to the PCH Referral Office. Please call Perth Children’s Hospital Switch on 6456 222 to discuss referral with Paediatrician on call.

Essential information to include in your referral

  • A tracked percentile chart with all previous measurements of weight, length, and head circumference
  • Where available, Z-scores should be included.
  • Results of previous investigations
  • Medical history including neonatal history, feeding/nutrition history, psychosocial history, developmental history
  • Details of current management plan.


  1. Motil, K and Duryea, T. Poor weight gain in children younger than two years in resource abundant countries: aetiology and evaluation. Up to Date. 2020. Retrieved from:
  2. Homan, G. Failure to thrive: A practical guide. American Family Physician. 2016 Aug 15; 94(4) 295-299.
  3. Becker, P et al. Consensus Statement of the Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition: Indicators Recommended for the Identification and Documentation of Pediatric Malnutrition (Undernutrition). Nutrition in Clinical Practice. 2014. 30 (1) p147-161. Retrieved from:
  4. Larson-Nath, C and Biank, V. Clinical review of failure to thrive in paediatric patients. Pediatric Annals. Vol 45 (2), 2016

Reviewer/team: Department of General Paediatrics Review date: Mar 2025

Date:  Mar 2022

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