Faltered growth (the preferred term replacing "failure to thrive") is defined in NICE NG75 by how far weight has fallen relative to where it started: a fall across 1 or more centile spaces if birthweight was below the 9th centile, 2 or more if birthweight was between the 9th and 91st, 3 or more if it was above the 91st — or a current weight below the 2nd centile whatever the birthweight. In the first weeks the triggers are different: a loss of more than 10% of birthweight, or failure to regain birthweight by 3 weeks. NICE NG75 and RCPCH growth chart guidance emphasise that faltered growth is multifactorial — most is related to intake rather than underlying organic disease, and most well children with isolated faltered growth do not need extensive investigation. Safeguarding should be considered in every case: faltered growth can be associated with neglect, but also with inadequate food provision, poverty, parental mental-health difficulties or feeding interaction problems; discuss concerns with the safeguarding lead and follow the local multi-agency pathway (NICE NG76, CG89). Medical red flags requiring urgent paediatric assessment include: severe undernutrition, developmental regression, organomegaly, dysmorphic features, recurrent infections, significant developmental delay, and parental concern disproportionate to examination findings. Two childhood cancers sit behind the organomegaly and pallor flags, which is why NICE NG12 (updated April 2026) is part of this step: an unexplained palpable abdominal mass or enlarged abdominal organ (or, for Wilms', unexplained visible haematuria) is a reason to consider a very urgent referral (within 48 hours) for neuroblastoma or Wilms' tumour, while unexplained petechiae or hepatosplenomegaly calls for immediate specialist assessment for leukaemia. The softer leukaemia features — pallor, fatigue, unexplained fever, persistent infection, generalised lymphadenopathy, bone pain, bruising or bleeding — call for a very urgent full blood count within 48 hours in a well child, who is then managed on that result; an unwell child with a combination of features needs same-day telephone discussion with acute paediatrics without waiting for the FBC. An abdomen examined only for "distension" can miss the mass that matters.

Measurement error is a common cause of apparent faltered growth in primary care — inconsistent clothing, uncalibrated scales and different measurement techniques all introduce error, so check technique and equipment before acting. WHO growth charts (UK-WHO) are used from birth to 4 years because they represent optimal growth for breastfed infants in a supportive environment. UK90 charts are used from 4 years onwards. A single weight below a centile means nothing without context — serial measurements demonstrating sustained downward crossing of centile lines is the diagnostic criterion. Mid-parental height calculation is essential for any child with short stature — familial short stature is the most common cause of small stature and requires no investigation if growth velocity is normal and MPH centile is concordant.

Most faltered growth in the UK is related to intake — the history must focus primarily on feeding before investigating for organic disease. Coeliac disease is the most commonly missed organic cause — it affects ~1% of the population and presents with faltered growth, steatorrhoea, and abdominal distension after gluten introduction. Cystic fibrosis should be considered in any child with recurrent chest infections and faltered growth — the newborn bloodspot screen (heel prick) screens for CF but false negatives occur. ARFID (Avoidant/Restrictive Food Intake Disorder) is increasingly recognised as a cause of inadequate intake in children — it requires specialist CAMHS and dietetic input and does not respond to standard feeding advice. Social history is not optional — food insecurity is common and can drive faltered growth; it needs practical support and signposting alongside clinical care, and is not in itself evidence of neglect. Always ask about Healthy Start voucher entitlement.

The examination in faltered growth serves two purposes: to identify organic disease and to assess for signs of neglect or abuse. A child who is alert, interactive, and well-engaged with parents despite a low weight is very different from one who is withdrawn, apathetic, and showing poor parent-child interaction — the latter requires medical assessment with safeguarding considered alongside. Dysmorphic features, cardiac murmurs, and organomegaly all require secondary care assessment. Tongue tie (ankyloglossia) is relevant only where there is demonstrable functional feeding difficulty (latch, milk transfer) — assessment by a trained infant-feeding practitioner decides whether division helps. Large tonsils should be interpreted with snoring, apnoeas, sleep quality and daytime function and managed via the sleep-disordered-breathing pathway, not assumed to explain poor growth.

NICE NG75 and paediatric consensus emphasise that investigation-driven approaches in faltered growth are ineffective — a focused history and examination identify the cause far more reliably than a "scatter-gun" blood panel. NICE NG75 recommends considering coeliac serology in faltered growth once gluten has been introduced — coeliac disease is significantly underdiagnosed. The child must be on a gluten-containing diet for at least 6 weeks before testing — parents sometimes withdraw gluten before the diagnosis is confirmed, which invalidates the test. Total IgA must be checked alongside anti-TTG to exclude IgA deficiency (which gives a false-negative IgA anti-TTG — use an IgG-based test if IgA deficient). Do not start a gluten-free diet before specialist confirmation. Sweat chloride testing for CF requires referral to specialist paediatric respiratory services — the test cannot be performed reliably in primary care. NICE NG75 frames the starting point narrowly: consider urine testing for UTI and coeliac serology, then investigate further only if the clinical picture points to a specific disorder. NICE NG20 asks that the child eats gluten in more than one meal every day for at least 6 weeks before serology — this is why parents are asked not to cut out bread and pasta while waiting.

Faltered growth is a quintessential MDT problem — no single professional can manage it effectively alone. The health visitor is the most important primary care professional in infant faltered growth — they have the frequency of contact, the home visiting capability, and the feeding expertise that GPs lack. The GP role is to exclude organic disease, identify safeguarding concerns, and coordinate the MDT. NICE NG75 asks for discussion with or referral to paediatric specialist services when there are symptoms or signs of an underlying disorder, when primary care interventions have not worked, when linear growth is slow or short stature is unexplained, when weight loss is rapid or undernutrition severe, or when there are safeguarding concerns. The primary care team should be able to call on an infant feeding specialist, a paediatric dietitian, a speech and language therapist with feeding expertise and a consultant paediatrician. The NICE NG12 row is separate from all of this: a mass or organomegaly is a cancer question first and a nutrition question second. Where maltreatment is suspected, refer to Children's Social Care via the local safeguarding pathway — the local authority, not the GP, decides whether early help, a section 17 assessment or a section 47 enquiry follows (Children Act 1989). Statutory guidance (Working Together to Safeguard Children 2026), NICE NG76/CG89 and GMC safeguarding guidance expect GPs to share concerns, discuss with the safeguarding lead and refer where indicated. Delay in safeguarding referral is a recurring finding in serious case reviews.

Caloric enrichment (adding fat and protein to existing foods) is more effective and better tolerated than volume increases for most children with faltered growth — it avoids overwhelming small appetites. Where nutritional support is needed, a dietitian calculates the child's individual requirements — universal calorie targets can be unsafe with unrecognised metabolic, cardiac, renal or gastrointestinal disease. Oral nutritional supplements should be prescribed according to local formulary arrangements, preferably with dietetic involvement, given between meals and reassessed — they should supplement, not replace, normal foods. Pancreatic enzyme replacement (Creon) for CF must be given with every meal and snack — undertreatment causes malabsorption and persistent faltered growth despite adequate intake. For coeliac disease, strict gluten-free diet (not just low-gluten) is essential — even small amounts of gluten cause ongoing villous atrophy and malabsorption. NICE NG75 puts an oral liquid nutritional supplement after other measures: consider a trial when faltering continues despite feeding support and dietary change. Tube feeding is a specialist decision made after multidisciplinary assessment, never a primary care step. Product names and energy densities (Infatrini, SMA High Energy, PaediaSure, Fortini) and doses of Creon, levothyroxine and vitamin D should be checked in the BNF for Children before prescribing.

The "division of responsibility" in feeding (Ellyn Satter model) is evidence-based — parents control what food is offered, when, and where; the child controls whether and how much they eat. Pressure-based feeding strategies (coaxing, bribing, force) reliably worsen food refusal and increase mealtime anxiety, causing a negative cycle. Reducing pressure, even when a child is failing to thrive, produces better long-term outcomes than pressure-based approaches. Maternal postnatal depression affects feeding responsiveness — mothers with depression are less likely to recognise infant hunger cues, feed responsively, or persist with breastfeeding. Treating maternal mental health is a direct intervention for infant growth. Food poverty is a structural issue affecting many UK children — practical social support (food banks, Healthy Start vouchers, benefit entitlement checks) is a clinical intervention, not a social nicety. NICE NG75 explicitly recommends addressing social determinants of growth faltering as part of clinical management.

The frequency of monitoring should be tailored to severity and risk — NICE NG75 explicitly warns against over-frequent weighing, which creates parental anxiety and a medicalization of normal infant weight variation without improving outcomes. Catch-up growth is individual — NICE NG75 recommends a management plan with specific goals rather than a universal catch-up timeframe. Non-engagement with follow-up in the context of faltered growth should prompt safeguarding consideration and discussion with the safeguarding lead rather than simply being documented as "did not attend." Documenting safeguarding concerns contemporaneously (date, time, observations, who was present, what was said) is legally important and protects both the child and the clinician. The RCPCH Growth Chart guidelines recommend that growth monitoring should be part of a structured plan with clear escalation criteria documented at each review — "safety-netting" must be specific and recorded. In the SCA the mark usually turns on two things: whether the candidate explains why one number is not a diagnosis, and whether they treat missed appointments and food insecurity as clinical findings. Framing money worries as something the practice can help with, rather than a failing, keeps the family engaged — and engagement is what makes the review plan work.