Case Based Pediatrics For Medical Students and Residents
Chapter II.5. Failure to Thrive
Anthony P. S. Guerrero, MD
December 2001

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This is a 12 month old female who presents for a well child check. Within the past 4 months, her weight has fallen from the 25th percentile to significantly less than the 5th percentile. Her height has dropped from the 10th percentile to slightly less than the 5th percentile, while her head circumference has remained at about the 25th percentile. Her language, motor, cognitive, and social development are normal. She seems to eat appropriate foods for her age, but the her mother notes that she tends to be restless and fidgety while eating, and that she does not like the texture of certain foods, often leading to parental frustration at mealtimes. Her stools tend to be frequent, with particles of food seen. Urine is normal. There are no symptoms of respiratory or neurological disease, and her review of systems is otherwise negative.

Her past medical history is entirely unremarkable. She was born at term, weighing 3.0 kg (6 pounds, 10 ounces), without any perinatal complications. Her family history is negative for any endocrinopathies or chronic illnesses. Mother is 155 cm (5 feet, 1 inch) 61 inches tall, and father is 168 cm (5 feet, 6 inches). Mother experienced menarche at age 12.5 years and recalls that there were other children in the family who were deemed small as young children but who caught up later in childhood. Mother describes a history of increased sadness and worry since her child was born. Parents are married, and there is no history of abuse or violence in the household.

Exam: Vital signs, including blood pressure, are normal. Weight 7 kg (< 5th percentile), height 70 cm (5th percentile), head circumference 45.5 cm (50th percentile). She is alert and interactive, and appears to relate well with her mother. Her anterior fontanelle is still open, roughly 2 cm. Two teeth (one just emerging) are present. Thyroid, lymph nodes, heart, lungs, abdomen, genitalia, nervous system, and skin are all normal.

Laboratory studies: CBC, chemistry panel, lead level, TSH, urinalysis, PPD, and stool studies, including ova and parasites all normal. Bone age is consistent with skeletal maturity of an 8 month old infant.

Formulation: Failure to thrive, with components of genetic short stature with a family history of constitutional growth delay. Parental anxiety, active temperament, and oral/tactile sensitivity may lead to feeding difficulties.

Clinical course: The primary care physician sees the child and family every few months for support, ongoing education, and coordination of services. A dietitian assists in devising an enhanced calorie diet for the child. An occupational therapist offers suggestions for reducing sensitivity to certain food textures. A psychiatrist provides treatment for what is felt to be mild post-partum depression in the mother. Two years later, the child is at the 5th percentile for both height and weight and is otherwise doing well.

Failure to thrive (FTT) is a clinical sign (rather than a specific diagnosis) that describes inadequate growth and is defined as (1) a child younger than 2 years of age whose: 1) weight is below the 3rd or 5th percentile for age on more than one determination; 2) weight is less than 80% of ideal weight (i.e., 0.8 times ideal weight) for age; or 3) weight crosses two major percentile curves on a standardized growth grid (2). FTT is a relatively common problem that may be seen in 10% of children in a rural primary care setting during the first year of life and may account for 1% to 5% of all referrals to children's hospitals and tertiary care settings (3).

The etiologies of FTT are diverse. To arrive at a list of differential diagnoses (which essentially can include most pediatric illnesses), one can think critically about the disease conditions that may interfere with any of the steps in the mechanisms leading to normal growth.

Feeding etiologies include food unavailability, neglect, improper feeding technique, appetite loss, food refusal, and neurologic conditions with impaired swallowing. Other etiologies may include intestinal disease conditions or anatomic abnormalities, endocrinopathies, chronic or prolonged infection, malignancies, other chronic diseases, toxic substances and metabolic derangements.

The patterns of increase in weight, height, and head circumference over time are important to note. Weight reduction out of proportion to height and head circumference may result from malnutrition. Weight reduction in proportion to height reduction but with sparing of head circumference may result from structural dystrophies, genetic short stature, and other endocrinopathies. Global weight, height, and head circumference reduction may result from central nervous system defects or intrauterine growth retardation. The timing of the reduction in weight may also be important to note, as a fairly sudden reduction in velocity of weight gain may reflect either the development of a chronic illness or an adverse social circumstance. Other specific signs and symptoms associated with FTT will vary according to the specific etiology (4).

Because the differential diagnosis can be so broad, a thorough history, growth chart review, and physical examination are key in the evaluation of FTT. Mindful of the mechanisms underlying normal and abnormal growth, one should elicit: a thorough feeding history (beyond the usual "diet" history), a comprehensive review of systems (which often gets dismissed in favor of "as per HPI"), a developmental and psychosocial history, and a history of family members' growth, development, and medical illnesses. It is potentially useful to determine the mid-parental height. For boys: father's height + mother's height + 13 cm]/2. For girls: father's height - 13 cm + mother's height]/2. Plot this on the growth grid for 2 to 18 year olds, estimate the percentile of the child's predicted height, and compare this to the current growth percentiles (as was done in the case above). However, parental short stature does not automatically imply genetic short stature, as either of the parents could have been adversely affected by malnutrition and/or chronic illness. Physical exam should include all vital signs and organ systems and should note the child's level of physical development (e.g., fontanelle size, dentition, etc.).

In the child with a "normal" history and physical examination, there is no clear consensus on what should constitute a "screening" laboratory evaluation, and it is possible that certain laboratory tests may have more value for reassurance rather than substantial diagnostic yield. However, it may be reasonable to consider a complete blood count, basic chemistries, urinalysis, and tuberculin test (1). Laboratory tests that would be appropriate for routine well child care (e.g., lead level) are also reasonable. Further laboratory tests should be guided by specific findings on history and physical examination. In the case above, stool studies were obtained because of the possibly abnormal stools, and a TSH and bone age were obtained because of the possibly delayed skeletal growth.

Management of FTT is based upon a sound understanding of the underlying etiologies. Traditionally, FTT has been categorized into "organic" and "non-organic" etiologies, but recently, it has been recognized that nearly every case of FTT may have both "organic" components (e.g., cyanotic heart disease) and "non-organic" components (e.g., the stressful feeding interactions taking place around a fragile, fussy child), thereby challenging the clinician to approach management in a comprehensive manner. For the case described above, there are multiple interactions between the various factors: for example, the perception of an "abnormal" child (being small for age; albeit with a strong constitutional element) could increase parental anxiety (compounding the depressive symptoms) and could render the parent-child interactions (already challenged by the child's active temperament and sensitivity to food textures) even more difficult. Hence, ongoing support and education from the primary care physician and referrals to psychiatry and occupational therapy become important components of the treatment plan.

An important priority is the establishment and maintenance of adequate nutrition, and caloric intake should be determined based upon child's age, need for "catch up" growth, and (if applicable) increased needs in illness. Creative methods, including more frequent meals and snacks, high calorie foods (e.g., peanut butter, margarine), and nutritional supplementation (e.g., PediaSure) can be employed to augment the child's natural intake. If these methods are unsuccessful after a reasonable trial, supplementation via nasogastric feeds may be indicated.

In the past, hospitalization was felt to be important in differentiating between "organic" and "non-organic" etiologies, as it was believed that the former would not gain weight in the hospital, while the latter would. However, hospitalization may not necessarily distinguish the two, as children with "organic" FTT may, in fact, gain weight with around the clock feeding in the hospital, while certain children with "non-organic" FTT (e.g., with conditions involving an anxious temperament and/or difficulty adjusting to new environments) may become even less likely to feed in a hospital setting. On the other hand, hospitalization must be considered in cases where a child is at risk of serious medical morbidity as a result of either malnutrition or the condition underlying the FTT or at risk of neglect or abuse.

Children with FTT have been found to be at higher risk for adverse cognitive and other developmental/behavioral outcomes, although it is not clear the extent to which these are related to the medical conditions underlying the FTT, subtle neurological dysfunctions which manifested themselves pre-morbidly as feeding and interactional difficulties (hence FTT), or ongoing psychosocial adversity. Nevertheless, because of the known importance of good nutrition for brain development during the first few years of life, it is highly important to identify any potential growth disturbances and suboptimal feeding practices during routine well child care and to expeditiously manage FTT.

Questions (true or false):

1. "Organic" and "non-organic" FTT are clearly defined conditions which enable pediatricians to focus treatment on "organic" cases.

2. Hospitalization is indicated when a child is at risk of serious medical morbidity or abuse/neglect.

3. In addition, all children with FTT should be hospitalized to distinguish between "organic" and "non-organic" etiologies.

4. Blood pressure is useful in evaluating young children with FTT.

5. If both parents are of short stature, then the child must have genetic short stature.

6. History, growth chart review, and physical are key in the evaluation of FTT.

7. In evaluating a child with FTT, it may be important to elicit any history of excessive thirst, increased urination, and family members with renal disease.


1. Zenel JA. Failure To Thrive: A General Pediatrician's Perspective. Pediatr Rev 1997;18: 371-378.


3. Kirkland RT. Failure to Thrive. In: McMillan JA, DeAngelis CD, Feigin RD, Warshaw JB (eds). Oski's Textbook of Pediatrics, third edition. 1999, Philadelphia: Lippincott Williams & Wilkins, pp. 752-755.

4. Gotlin RW, Klingensmith GJ. Chapter 26 - Endocrine Disorders. In: Hathaway WE, Groothuis JR, Hay WW, Paisley JW (eds). Current Pediatric Diagnosis and Treatment, 9th edition. 1991, Englewood Cliffs, NJ: Appleton & Lange, pp. 773-774.

Answers to questions

1.F, 2.T, 3.F, 4.T (can help detect renal disorders), 5.F, 6.T, 7.T

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