The preterm infant is at high risk for malnutrition. This risk is related to reduced nutrient stores at birth, imma- ture organ systems for nutrient absorption and utiliza- tion, delayed advancement of parenteral and enteral feeds, and dependence on the healthcare provider to identify and meet nutritional needs during a period of rapid growth and development.55 Malnutrition in the preterm infant and neonate can have a lifelong negative impact.
In early 2018, The Journal of the Academy of Nutri- tion and Dietetics published recommended indicators for identifying malnutrition in preterm infants and neo- nates. These suggested criteria were authored by an expert panel of Neonatal Registered Dietitians from the Pediatric Nutrition Practice Group. These recommended indictors were evidence informed and consensus driven.56
The data used to assess for the presence of malnutri- tion of the preterm infant or neonate is similar to those used for the pediatric population. Evaluating nutri- ent intake, anthropometric measurements, and growth velocity are used in order to determine if an infant is malnourished. The 2013 Fenton preterm growth chart or the 2010 Olsen intrauterine growth curves are the ref- erence standard and should be used for infants born at 36 weeks and 6/7 weeks or earlier.57,58 The WHO child growth standards should be used for infants born at 37 0/7 weeks’ gestation and older.
Growth assessment begins at birth by identifying whether an infant is small for gestational age (SGA), appropriate for gestational age (AGA), or large for gestational age (LGA) or has experienced intrauterine growth restriction (IUGR). SGA is defined as a z-score below −1.25 (less than the 10th percentile) for gestational age, AGA is a z-score between −1.25 and 1.25 (10th to 90th percentile). IUGR is defined as a pathological pro- cess that causes weight to be less than the genetically pre- dicted weight. IUGR is diagnosed by intrauterine growth failure with normal head circumference.59
Regain of birth weight: Most infants, both term and preterm, demonstrate an initial postnatal weight loss. This usually results in a loss of 7%–10% of birth weight during the first few days of life. It is generally expected that infants will regain birth weight by 7 to 14 days of age.60 When used in conjunction with adequate nutrient intake, the length of time required for the infant to regain birth weight when longer than usual suggests malnutrition.
Weight gain velocity: The growth goal for the infant to maintain a weight gain velocity that will allow them to improve or maintain stability of their weight for age z-score/percentile ranges from 15 grams to 30 grams per
day.61 As with older children, weight gain velocity that is less than the weight gain needed to maintain stable growth is an indicator of malnutrition.56
The rate of weight gain velocity needed to maintain a stable weight for age z-score varies with weight, age, and gender; therefore, weight gain velocity goals need to be adjusted frequently.61 Weight gain goals can be estab- lished using preterm growth charts or a preterm growth calculator program or application.
Change in weight for age z-score: Faltering growth as indicated by a decline in weight for age z-score is one of the recommended indicators for identifying malnutri- tion in the preterm/neonatal population.
The indicator for decline in weight for age z-score is based on the study by Rochow and colleagues.62
This large, international, longitudinal, observational study reported that infants with uncomplicated post- natal adaptation transitioned to a weight gain trajectory 0.8 SD below birth at day of life 21. The cutoffs for mild, moderate, and severe malnutrition also reflect the very rapid expected rate of weight gain of preterm infants and neonates.
Length: The indicators related to length include less than expected linear growth velocity and decline in length for age z-score.
Linear growth is dependent on fat-free mass accretion and adequate protein and micronutrient intake. Therefore, assessment of linear growth may be used in conjunction with nutrient intake in identifying malnutrition.56,63,64
Criteria for identifying malnutrition in the preterm infant are described in TABLE 4 .8.
▸ Conclusion
The goal of this chapter is to provide the pediatric nutrition professional with the tools needed to identify, document, and treat malnutrition in children from birth into adult- hood. In recent years, pediatric nutrition professional organizations have begun working together in order to standardize the definition of pediatric malnutrition and
TABLE 4 .7 Recommended Timeframes for Monitoring of Pediatric Malnutrition
Mild Malnutrition Inpatient: one time per
week Outpatient: one time per
month Community: monthly
Moderate Malnutrition Inpatient: 1–2 times per
week Outpatient: one time per
week Community: weekly
Severe Malnutrition Inpatient: every 1–3 days Outpatient: one time per
week Community: weekly
TABLE 4 .8 Recommended Indicators of Preterm/Neonatal Infant Malnutrition
Primary Indicator Mild Malnutrition Moderate
Malnutrition Severe
Malnutrition Use of Indicator Days to regain birth
weight 15–18 days 19–21 days >21 days Use in conjunction
with nutrient intake Weight gain velocity
Not appropriate for first 2 weeks of life
<75% of expected rate of weight gain to maintain growth rate
<50% of expected rate of weight gain to maintain growth rate
<25% of expected rate of weight gain to maintain growth rate
Decline in weight of z-score
Not appropriate for first 2 weeks of life
Decline of 0 .8–1 .2 in
z-score Decline of >1 .2–2 in
z-score Decline of >2
z-score
Linear growth
velocity <75% of expected
rate of weight gain to maintain growth rate
<50% of expected rate of weight gain to maintain expected growth rate
<25% of expected rate of weight gain to maintain expected growth rate
May be deferred until day of life 14 and in critically ill unstable infants
Use in conjunction with another indicator when accurate length measurement available
Decline in length of z-score
Not appropriate for first two weeks of life
Decline of 0 .8–1 .2 in
z-score Decline of >1 .2–2 in
z-score Decline of >2 in
z-score May be deferred until
day of life 14 and in critically ill, unstable infants
Use in conjunction with another indicator when accurate length measurement available Nutrient Intake
The best indicator during the first 2 weeks of life
≥ 3–5 Consecutive days of protein/
energy intake ≤75%
of estimated needs
≥ 5–7 consecutive days of protein/
energy intake ≤ 75%
of estimated needs
>7 consecutive days of protein/
energy intake
≤ 75% of estimated needs
adopt common recommended indicators to identify and document its diagnosis and care.
Although the prevalence of pediatric malnutrition remains unknown at this time, those who care for chil- dren continue to work to identify, diagnose, and treat
malnutrition at all ages. The causes of malnutrition are many and are not addressed in this chapter. Other chapters provide information on diseases and conditions that put children at risk for malnutrition, as well as offer nutrition therapy recommendations for treatment.