Faltering Growth in Children

🔍 When to Suspect

A child's weight or rate of weight gain is significantly below that of their peers, typically defined as a fall across ≥1 centile space (birth weight <9th centile), ≥2 spaces (9th–91st centile), or ≥3 spaces (>91st centile) on a growth chart, or current weight below the 2nd centile for age

From the full topic in The Ocean Library: Faltering Growth in Children

🧭 When to suspect

Faltering growth (the modern term for what was called ‘failure to thrive’) describes a slower rate of weight gain than expected for an infant or preschool child’s age and sex. It is a descriptive pattern, not a diagnosis – most cases are nutritional and non-organic, but an underlying cause must always be considered. It is common, with concerns arising in up to ~5% of infants and preschool children.

Recognition rests on plotting growth on the UK-WHO growth chart (World Health Organization reference charts used across the UK) and applying the NICE thresholds for concern. A centile space is the gap between two adjacent printed centile lines on the chart. Suspect faltering growth when the fall in weight centiles meets the birth-weight-dependent threshold below, or when current weight is below the 2nd centile for age.

Scenario	Threshold for concern
Birth weight below the 9th centile	A fall across 1 or more weight centile spaces
Birth weight 9th–91st centile	A fall across 2 or more weight centile spaces
Birth weight above the 91st centile	A fall across 3 or more weight centile spaces
Any birth weight	Current weight below the 2nd centile for age

Two definitions of terms used throughout: an infant is a baby up to 1 year of age, and a child here means a preschool child from 1 year onwards.

🧠 Clinical pearl The pattern of centile fall hints at the cause. In the common nutritional picture, weight falls first while length and head circumference are relatively preserved. If weight and length fall together, think a more significant problem – an endocrine or genetic cause. If head circumference falls early too, be more concerned about a serious systemic or neurological disorder.

Source: NICE NG75

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