Failure to thrive diagnostic study of choice
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There is no diagnostic study of choice for failure to thrive. Various definition such as weight for age less than the 5th percentile for age, weight for height less than the 5th percentile for age or a drop in more than two percentiles on the growth chart may be used. The initial approach involves a thorough history and physical examination. This will help narrow the diagnosis, identify red flags and then determine the need for hospitalization.
- There is no specific definition for failure to thrive.
- The culprit is usually an insidious in onset combination of nutritional and psychological deprivation causing a growth rate that is lower than expected in a pediatric patient’s age. 
- In order to achieve this, an accurate quantitative anthropometric definition of the child’s nutritional status, a through initial history and physical examination is required. 
- It is important not to just take one measurement in one visit and label the patient with a diagnosis of failure to thrive ; ‘child is below the 5th percentile for height and weight’.
- Instead, one should first establish a weight/height relationship by using a combination of criterion such as weight for age, height for age and ideal weight for height.
- It will help appreciate the severity of malnutrition and guide the physician’s diagnostic and therapeutic plan.
- Weight for age and theoretic body weight are the more specific indices. "Failure To Thrive - StatPearls - NCBI Bookshelf".
- Theoretic body is defined as the weight that the child should have had at the time of admission if he/she had continued to gain weight along the previously established percentile during the pre-morbid period.
- Weight for length is a good indicator of acute malnutrition as it is determined by the fat stores present in a patient.
- If found below the normal limits, a child can be initially labelled as a ‘weight falterer’. This is a less negative/alarming term that can be used till a more progressive long term follow up can confirm the diagnosis of failure to thrive.
- During the period of hospitalization or the follow up periods, if weights are checked daily then they should be checked on the same scale at the same time and wearing either the same or no clothes. "Failure to Thrive: A Practical Guide - American Family Physician".
- However, this is not recommended. Weight change is better averaged when measured at intervals of weeks – months until normal growth velocity is achieved.
- Growth potential can be assessed by collecting the parents’ anthropometric measurements, asking the same about the patient’s relatives and plotting mid parental heights.
- Mid parental height can be calculating 12.5 cm to the mother’s height of a male infant or subtracting 12.5cm from the father’s height of a female infant. Remember that parents tend to overestimate their heights.
- Measurements should be plotted on standardized charts (WHO, NCHS, CDC).
- Specialized growth charts should be used for cases like prematurity, trisomy’s, Turner syndrome, intrauterine growth restriction. etc.
- Various definitions include: 
- Based on attained growth
- Weight less than 3rd percentile on NCHS growth chart.
- Weight for height less than 5th percentile on NCHS growth chart.
- Weight less than 80% of ideal weight for age, in a child younger than 2 years.
- Triceps skin-fold thickness less than or equal to 5 mm.
- Based on rate of growth:
- Depressed rate of weight gain:
- <20 gm/day from 0–3 months of age.
- < 15 gm/day from 3–6 months of age.
- Fall off from previously established growth curve:
- Downward crossing of more than or equal to two major percentiles on NCHS growth chart. (percentile markers 95, 90, 75, 50, 25, 10, and 5)
- Documented weight loss.
Diagnostic Study of Choice and Initial holistic approach
- There is no diagnostic study of choice for patients with failure to thrive.
- The evaluation of the patient starts right from the time the patient and the parents walk into the room.
- The physician will be able to pick up on subtle clues that would help him explain the multifactorial pathology of failure to thrive.
- For example, differentiating failure to thrive from low birth weight infants, extreme prematurity and individuals with low mid parental height can be achieved simply by looking at the energy/awareness of the child and parent- child interaction.
- Therefore, the initial holistic approach would comprise a detailed history, physical examination and anthropometric measurements (weight, height and head circumference) of the patient and the parents. 
- The word holistic is so important as there are various psychological, nutritional, financial and pathological etiologies in each patient with failure to thrive.
- Understanding of basic concepts such as prematurity, intra-uterine growth restriction, non accidental trauma, child neglect, catch up growth (seen in light for date babies) and catch down growth (child’s growth slows down so that growth can occur according to the child’s genetic potential) will help the physician to understand whether the pathology is due to decreased calorie intake/absorption or due to increased calorie expenditure. 
- The physician would then be able to pick up on red flag signs and decide whether the patient requires immediate hospitalization or can be treated at home.
- Using the Gomez criteria one can determine the severity of undernutrition. It involves comparing the weight for age with the 50th percentile for that age (< 60- servere, 51-75 – moderate and 76-90 - mild).
- Parents should notice the interaction between the parents and the child as certain behavioral patterns help differentiate between organic and non organic causes.
- Asking the parent to feed the child, particularly at a time when the child is hungry can help the physician assess the child’s cues, responsiveness, temperament, and the parent’s warmth/behavior. One needs to build a complete picture of their relationship. 
- Hospitalization is rarely required and is a matter of much debate.
- Hospitalization helps monitor the patient-parent interaction, the child’s diet and demeanor. 
- Through structured diets and a multidisciplinary approach, it is associated with an increase in weight.
- A care by parent unit helps offers special advantages in treating such patients not only during the acute phase but also just before the patient is discharged.
- However, an increase in weight does not rule out an organic cause of failure to thrive. Hospitalization may also promote more anxiety and anorexia in the patient through separation from the parent and an improvement in the child’s condition may reveal insecurities/inadequacies in parents.
- After a review of 122 hospital records, a study found that only 0.8% of investigations uncovered the diagnosis of an organic failure to thrive. It concluded that a careful history and physical examination picks up social and environmental factors that form the basis of the diagnosis of failure to thrive. 
- Indications for hospitalization include: "Failure to Thrive: A Practical Guide - American Family Physician".  
- Z scores below the 50th percentile
- Signs of abuse/neglect
- Signs/symptoms/complications of a medical cause of failure to thrive. (cardiac murmurs, elevated JVP, heart failure signs, organomegaly, lymphadenopathy, recurrent vomiting, diarrhea, dehydration, recurrent infection)
- Parental impairment/anxiety
- Poor parent-child interaction
- Outpatient treatment failure (failure to gain weight despite adequate intake)
- Fear of child’s safety
- Severe malnutrition/dehydration/ dysmorphic feature
- Need for a structured diet program/nutritional rehabilitation
- Venkateshwar V, Raghu Raman TS (2000). "FAILURE TO THRIVE". Med J Armed Forces India. 56 (3): 219–224. doi:10.1016/S0377-1237(17)30171-5. PMC 5532051. PMID 28790712.
- Marcovitch H (1994). "Failure to thrive". BMJ. 308 (6920): 35–8. doi:10.1136/bmj.308.6920.35. PMC 2539114. PMID 8298353.
- Jeong SJ (2011). "Nutritional approach to failure to thrive". Korean J Pediatr. 54 (7): 277–81. doi:10.3345/kjp.2011.54.7.277. PMC 3195791. PMID 22025919.
- Goh LH, How CH, Ng KH (2016). "Failure to thrive in babies and toddlers". Singapore Med J. 57 (6): 287–91. doi:10.11622/smedj.2016102. PMC 4971446. PMID 27353148.
- Krugman SD, Dubowitz H (2003). "Failure to thrive". Am Fam Physician. 68 (5): 879–84. PMID 13678136.
- Berwick DM, Levy JC, Kleinerman R (1982). "Failure to thrive: diagnostic yield of hospitalisation". Arch Dis Child. 57 (5): 347–51. doi:10.1136/adc.57.5.347. PMC 1627558. PMID 6807215.
- Goldbloom RB (1982). "Failure to thrive". Pediatr Clin North Am. 29 (1): 151–66. doi:10.1016/s0031-3955(16)34114-1. PMID 6276853.