SGEM#523: Everything Grows and Grows…Until it Doesn’t. Clinical Practice Guidelines for Faltering Weight

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Reference: Kersten HB, et al; American Academy of Pediatrics and North American Society for Pediatric Gastroenterology, Hepatology and Nutrition. Clinical Practice Guideline for Diagnosis and Management of Faltering Weight. Pediatrics. 2026.

Date: September 15, 2026

Dr. Salina Khushal

Guest Skeptic: Dr. Salina Khushal is a Pediatric Gastroenterologist at the Pediatric Specialists of Virginia. She completed her fellowship at Johns Hopkins University School of Medicine and her pediatrics residency at Children’s National Hospital. Her research interests include inflammatory bowel disease, celiac disease, eosinophilic esophagitis, and constipation.

Case

A 7-month-old infant is sent to the emergency department (ED) for failure to thrive workup (FTT). The parents report that the baby has always been small, but over the past two months, weight gain has slowed. On your exam, the child is not febrile, is smiling, is hydrated, and has normal vital signs.

The parents report that feeding has become more difficult since the infant started solids. It has also been difficult maintaining breastfeeding supply after the parent returned to work.

They are worried and ask: “Is something seriously wrong? What testing do you have to do? Does our baby have to stay in the hospital?”

Background

FTT has been around for decades, but the term has always been messy. The term is vague, inconsistently defined, and can feel blaming to families. The word “failure” lands hard when parents are already worried about their child’s growth. It is also not a single disease. It is a descriptive label applied to children who are not gaining weight or growing as expected. While it may seem like this is a more outpatient or subspecialist issue, we are often tasked with evaluating these patients in the ED and determining disposition.

The new American Academy of Pediatrics (AAP) and North American Society for Pediatric Gastroenterology, Hepatology, & Nutrition (NASPGHAN) clinical practice guideline updates the language from “failure to thrive” to “faltering weight.”

This guideline includes 8 Key Action Statements and 4 Good Practice Statements.

The guideline moves away from relying on percentiles and tries to standardize the diagnosis using z scores. That is a major shift. Many previous definitions used weight below the 3rd or 5th percentile, weight-for-length below the 5th percentile, or crossing two major percentile lines.

The guideline defines faltering weight as any of the following:

Weight-for-length or BMI-for-age less than −1.65 z score, which corresponds roughly to the 5th percentile
In children younger than 2 years, weight gain velocity less than −2 z score for age
Decline in weight, weight-for-length, or BMI of 1 z score or more

Previ0usly, failure to thrive was often divided into organic and non-organic causes. Organic causes meant that faltering weight was attributed to an identifiable medical condition or disease process, such as congenital heart disease, cystic fibrosis, chronic infection, malabsorption, renal disease, or genetic syndromes. Non-organic causes meant poor weight gain was attributed to psychosocial, environmental, behavioral, feeding, or caregiving factors. Examples might include inadequate caloric intake, feeding technique problems, food insecurity, caregiver mental health concerns, etc.

The new guideline moves away from that framework because it is too simplistic. Poor weight gain is usually multifactorial, with medical, nutritional, developmental, feeding, behavioral, and social factors often interacting at the same time. Rather than trying to place children into one of two buckets, the guideline encourages clinicians to identify the specific contributors to faltering weight and tailor evaluation and management to the child and family.

This clinical practice guideline is primarily intended for pediatricians and other pediatric health care providers in the outpatient setting. The authors defined this group as primary care pediatricians, family practice physicians, subspecialty physicians, other specialty physicians (eg, gastroenterology, genetics), and other members of the team who care for children with faltering weight (eg, dentists, dietitians, feeding therapists, lactation consultants, nurses, nurse practitioners, nutritionists, oral surgeons, physician assistants, social workers, speech and occupational therapists, behavioral and/or functional therapists, feeding therapists, and pediatric psychologists).

However, children with poor weight gain are often referred to the ED for urgent evaluation, laboratory testing, or admission. That makes this guideline relevant to pediatric emergency medicine, even if it was not designed specifically for the ED.

Clinical Question: In young children with faltering weight living in high-resourced settings, which diagnostic, nutritional and feeding strategies identify important underlying disease and improve growth while minimizing harms, costs, burden and inequity, and should socioeconomic status be used as a diagnostic risk factor?

This was built around six prioritized questions.:

Whether socioeconomic status predicts faltering weight
Whether diagnostic testing should be performed to look for an underlying condition
Whether calories should be increased
Whether oral supplements or higher-calorie formulas should be used
Whether feeding or speech therapy should be provided
When endoscopy is useful, including which clinical features predict an abnormal finding

Population: Children with poor weight gain or suspected faltering weight. The systematic reviews informing the guideline largely focused on children aged 0–5 years in high-resourced countries.
- Common exclusions were populations from low- and middle-resourced countries, children being fed through a nasogastric tube, studies dominated by older children or adults, and non-English-language reports. Review-specific exclusions also removed case reports, secondary research, reports of tests no longer in routine use and studies that did not provide an outcome relevant to diagnosis or treatment of faltering weight. These exclusions make the population more consistent with North American outpatient practice, but they also narrow generalizability.
Exposure/Intervention: The exposure question was socioeconomic status. The diagnostic interventions included laboratory tests, imaging and gastrointestinal endoscopy with biopsy. The treatment interventions were increased calories or energy density, higher-calorie formula or oral nutritional supplements, and multidisciplinary feeding interventions involving dietitians, speech-language pathologists, occupational therapists, home visitors or other members of a feeding team.
Comparison: The comparators were no assigned socioeconomic risk factor, no routine diagnostic testing, no endoscopy, no increase in calories, no oral supplementation, no feeding intervention or usual care. Usual care was not standardized across all studies and ranged from ordinary primary care to clinic-based nutritional advice. There was no conventional placebo group for most questions.
Outcome:
- Primary Outcomes. The guideline did not specify one overall primary outcome. Outcomes varied by question and included the frequency of faltering weight, identification of an underlying disease, diagnostic yield and accuracy, endoscopy findings and complications, and changes in growth or weight gain.
- Secondary Outcomes. Other outcomes included height, calorie intake, development, feeding ability, oral intake, and meeting nutritional needs. The panel also considered potential harms and practical issues, such as false-positive results, additional testing or referrals, hospitalization, procedural complications, excessive weight gain, feeding stress, cost, access, feasibility, and health equity. Many of these outcomes were considered by the panel but were not directly measured in the included studies.
Type of Study: Clinical practice guideline using GRADE methodology, systematic reviews, evidence-to-decision frameworks, and expert consensus.

Authors’ Conclusions: This CPG renames the condition formerly called “failure to thrive” as “faltering weight.” It also standardizes diagnostic criteria and proposes initial management for this condition as well as an equitable approach. Because this CPG was codeveloped with NASPGHAN, it also provides guidance regarding considerations for endoscopy in children with faltering weight. Challenges remain regarding the adoption of this CPG, and doing so will require changes in EHRs and, potentially, in office procedures. Education of patients, families, pediatricians, and the health care team—along with enhanced information technology solutions—will be needed to help translate these recommendations into clinical practice.

Quality Checklist for a Clinical Practice Guideline

The study population included or focused on those in the emergency department. No.
An explicit and sensible process was used to identify, select, and combine evidence. Yes.
The quality of the evidence was explicitly assessed using a validated instrument. Yes.
An explicit and sensible process was used to assess the relative value of different outcomes. Yes.
The guideline thoughtfully balances desirable and undesirable effects. Yes.
The guideline accounts for important recent developments. Unsure.
The guideline has been peer-reviewed and tested. Yes and No.
Practical, actionable, and clinically important recommendations are made. Unsure
The guideline authors’ conflicts of interest are fully reported, transparent, and unlikely to sway the recommendations.
Mostly yes.

Here are FIVE of the key recommendations relevant to the ED:

Stop using failure to thrive as the preferred label.
Use z scores, not just percentiles.
Accurate anthropometrics are not optional.
Do not use socioeconomic status as a diagnostic risk factor.
Be deliberate in working up these children.

GRADE:

This guideline reflects a broader methodological shift for the AAP. Historically, many clinical practice guidelines relied heavily on expert consensus, and the AAP previously used its own evidence-rating system. The AAP has now transitioned to GRADE, which stands for Grading of Recommendations, Assessment, Development and Evaluation. GRADE is used by many major guideline-producing organizations and is meant to make recommendations more consistent, transparent, and comparable across groups.

One key feature of GRADE is that it separates the certainty of the evidence from the strength of the recommendation. Evidence can be high, moderate, low, or very low certainty, but the final recommendation also considers the balance of benefits and harms, patient and caregiver values, resource use, feasibility, acceptability, and equity. That is especially important in pediatrics, where large, randomized trials are often limited or impractical.

Several recommendations in this guideline are strong recommendations despite very low-certainty evidence. That can feel contradictory, but it can still be appropriate within the GRADE framework.

For example, the evidence that routine diagnostic testing improves outcomes in children with faltering weight is very limited. But the potential downsides are real: false positives, cost, family anxiety, additional referrals, testing cascades, unnecessary hospitalization, and inequitable burdens on families with fewer resources. So even with very low-certainty evidence, a strong recommendation against routine testing can make sense when the expected benefit is trivial and the potential harms and costs are meaningful.

This is different from saying “we have high-quality evidence that testing does not work.” It is more like saying, “Given the limited evidence, low diagnostic yield, plausible harms, cost, feasibility concerns, and equity implications, routine testing should not be the default.” That distinction is important for ED clinicians, because it supports targeted testing when the history or exam points to a specific concern, while discouraging the reflexive “failure to thrive lab panel” in a well-appearing child.

Outcome Measures.

Most measured outcomes were surrogates, and harms were poorly captured. Weight gain, BMI, z scores, growth quotient, energy intake and diagnostic yield are useful intermediate measures, but they are not automatically equivalent to better development, function, quality of life or family well-being.

Few studies followed children long enough to determine whether a short-term increase in weight improved neurodevelopment or produced later harms. Similarly, most studies did not prospectively collect false-positive cascades, caregiver anxiety, treatment burden, force-feeding, oral aversion, dental effects or excessive weight gain.

The panel thoughtfully discussed these outcomes, but discussion cannot substitute for measurement. EBM emphasizes the importance of patient (family) values and preferences and urges caution when recommendations rest mainly on physiological or surrogate endpoints.

Z scores are Precise, but not always Practical:

Z scores may be more precise than percentiles. This is especially true at the extremes of the growth chart. But be careful. A single z score can still be hard to interpret in isolation. Just because a child meets one definition of faltering weight based on one measurement does not automatically mean they are malnourished, acutely unsafe, or need admission from the ED. The trend matters. Prior measurements, rate of change, feeding history, and the clinical exam are often more informative than a single number from one ED visit. The z score can help identify a child who may need attention, but disposition still depends on the whole context.

The z-score criteria were developed through a modified Delphi consensus process rather than a prospective diagnostic-accuracy study tied to patient-important outcomes. The panel established an 80% agreement threshold, yet the criterion of a decline of at least one z score received only 78.5% support; the remaining members preferred a decline of 0.7. The authors also caution that not every child meeting the criteria is undernourished. This creates a risk of misclassification. An overly sensitive definition could label normal catch-down growth as disease and lead to anxiety, supplements and investigations, while an insufficiently sensitive threshold could delay recognition of genuine undernutrition. The guideline is transparent about this uncertainty and explicitly calls for prospective validation, but until that occurs the definition should be treated as a screening trigger rather than a diagnostic gold standard.

The other practical implementation component of this is that it depends on support from the electronic health record (EHR). If the ED EHR does not automatically display z scores and changes over time, clinicians may revert back to percentiles, gestalt, or also defer to the “primary care provider sent them here for admission” approach.

The science may be better, but implementation will determine whether this changes practice.

ED Testing:

Key Action Statement 2B of this guideline specifically states, “In a child without specific signs, symptoms, and findings that would prompt a focal evaluation, the AAP Guideline Panel recommends against diagnostic testing as part of the initial routine workup for faltering weight.” This was a strong recommendation based on very low certainty of evidence.

Signs and symptoms that should raise suspicion for GI organic disease (as opposed to solely poor caloric intake) include things like:

Vomiting, especially bilious, forceful/projectile, blood-streaked
Chronic diarrhea, especially with blood or mucus, or greasy stools which may point to malabsorption
Abdominal distension or other abnormal abdominal exam findings
Dysphagia, feeding refusal, gagging/choking (raises concern for swallow dysfunction, eosinophilic esophagitis, anatomic obstruction
Perianal disease, oral ulcers, or growth deceleration in the context of new-onset GI symptoms may point to new diagnosis inflammatory bowel disease (IBD)
Family history that points to celiac disease, IBD, or cystic fibrosis
Faltering weight despite a well-documented caloric intake as this points toward malabsorption or increased metabolic demand (versus simply inadequate caloric intake)

All of these are going to be important aspects of the history taking and physical exam. The guideline specifically discourages routine testing/endoscopy. While haphazard diagnostic tests may result in higher healthcare costs or false positive results, there may still be times when targeted testing is appropriate.

If there is concern for dehydration, electrolyte disturbance, or systemic illness, would consider lab work/imaging based on the specific symptoms/red flags.

If concerned for IBD: CBC, CMP (albumin), ESR/CRP, stool calprotectin/infectious studies if indicated. These would not return acutely, but may be helpful in expediting diagnosis.
If suspected celiac disease: TTG IgA and serum IgA. At a younger age, TTG IgA may not be sensitive enough.
If suspected pyloric stenosis: abdominal ultrasound.
If concern for obstruction/malrotation: XR, CT, or other imaging

Not ED-focused:

This guideline is multidisciplinary, but it is not ED-focused. The panel included a broad group of stakeholders: general pediatricians, gastroenterologists, a pediatric hospitalist, dietitian, psychologist, social worker, parent/caregiver liaison, endocrinologist, geneticist, epidemiologist, implementation scientist, and informatician. The guideline was also reviewed by a wide range of AAP committees, councils, and sections, including the Committee on Pediatric Emergency Medicine and the Section on Emergency Medicine.

That is reassuring because emergency medicine had a seat somewhere in the review process, but it does not mean that this is particularly helpful for the ED clinician. This matters because there is very little guidance on disposition when these children show up in the emergency department. The guideline tells us a lot about terminology, diagnostic criteria, testing, endoscopy, nutrition, and feeding therapy, but it does not clearly answer the ED question: Who needs to be admitted tonight, and who can safely go home with close follow-up?

ED clinicians still need to consider our priorities in the acute setting: identify instability, dehydration, severe malnutrition, hypoglycemia, red flags for underlying disease, and whether reliable follow-up is possible.

Admission decisions for faltering weight should be driven by acute medical risk and by whether safe outpatient follow up can be secured, not by the growth chart itself.

Admit for acute medical instability (independent of faltering weight workup): dehydration, electrolyte derangement, suspected obstructive/surgical process (ie bilious vomiting, peritoneal signs).
Admit for severe/acute on chronic nutritional compromise: concern for refeeding risk, inability to tolerate enteral intake in ED observational period, suspected/confirmed underlying condition that would impact ability to tolerate outpatient enteral nutrition, and/or may necessitate inpatient workup/initiation of treatment (new IBD flare, severe EOE with impaction, decompensated malabsorptive state)
Admit when outpatient safety/follow-through cannot be assured: concern regarding outpatient follow up, feeding intervention, close weight monitoring is not feasible. This aligns with the guideline’s spotlight on social drivers of health– social/access barriers, concern for caregiver inability to implement feeding plan at home.
Do NOT admit reflexively for isolated low percentile/z-score in an otherwise well-appearing, adequately hydrated, feeding child with no red flags.

Comment on Authors’ Conclusion Compared to SGEM Conclusion: We generally agree with the authors’ conclusion. The authors intend this guideline to reduce confusion, improve diagnostic accuracy, decrease overuse of testing and imaging, and improve care for children with faltering weight.

There’s a caveat: although this guideline does make some improvements to the previously vague definitions, stigmatizing language, and low-value workups, the overall evidence quality is still lacking, and it really was not built for emergency medicine. It should be used to support selective testing, careful disposition, and better communication but not to force ED clinicians to make a definitive outpatient diagnosis during a single acute visit.

SGEM Bottom Line: For a well-appearing child with poor weight gain, do not reflexively order a broad “failure to thrive” testing or admit for an extensive diagnostic expedition. Confirm accurate measurements, assess for acute illness and safety concerns, and work with the family and primary care physician to determine disposition. Use this guideline as a guardrail, not gospel, because the evidence is almost entirely very low certainty.

Case Resolution:

The infant is re-weighed naked on an infant scale, and the length is repeated with proper technique. The ED team reviews available growth data and confirms slowed weight gain but no acute weight loss. The infant is hydrated, has normal vital signs, and no respiratory, cardiac, abdominal, neurologic, or infectious red flags.

A feeding history suggests prolonged feeds, some difficulty with solids, and decreased breast milk supply after the parent returned to work. No broad laboratory or imaging workup is ordered.

The ED clinician discusses the case with the referring primary care pediatrician. Follow-up is arranged for repeat weight, feeding assessment, and referral to other community resources.

Clinical Application:

The guideline also emphasizes that faltering weight is a screening signal, not a final diagnosis. Not every child meeting these criteria is undernourished. Some children born large for gestational age drift down toward their genetic growth potential. Some children born small for gestational age or children with genetic syndromes may have different growth patterns. This is why the guideline stresses accurate measurements, trend over time, and clinical context.

For the ED, this guideline is both useful and incomplete. Useful because it supports what many pediatric emergency clinicians already suspect: the well-appearing child with poor weight gain rarely needs a broad ED laboratory or imaging workup. Incomplete because our job is usually not to solve faltering weight in one visit. It gives little specific guidance on ED disposition. Our job is to identify the child who is acutely unsafe, medically unstable, severely malnourished, dehydrated, hypoglycemic, abused or neglected, or unable to access reliable follow-up.

What Do I Tell the Patient?

Your child’s weight gain has slowed, and that is something we take seriously. Today, we do not see signs of dehydration, infection, breathing trouble, or another emergency. The most important next step is to make sure the measurements are accurate, understand how feeding is going. After that we can talk with you and your child’s primary care doctor about the possible options. Close outpatient follow-up may be appropriate so we can support the needs of your child and family.