Infant Nutrition Assessment: GROWTHBeth Ogata, MS, RD, CSPJoan Zerzan, MS, RDUW – CHDDbogata@uw.edu NUTR 526 – Fall 2012

Nutrition Screening and Assessment

Growth Data Used Throughout the Nutrition Care Process

• Screening• Assessment• Diagnosis• Monitoring and Evaluation

NCP: Nutrition Screening•Definitions

▫Process of identifying characteristics known to be associated with nutrition problems (ASPEN, 1996)

▫Simplest level of nutritional care (level 1) (Baer et al, 1997)

•Purpose▫Identify individuals who appear to have or be

at risk for nutrition problems▫Identify individuals who require further

assessment or intervention

Examples of Screening Risk FactorsAnthropometrics: weight, length/height, BMI•measures < 5th %ile•measures > 95th %ile•alterations in growth patterns

▫ change in Z-scores▫ change 1-2 SD▫ change percentile

channels

Medical Conditions

Medications

Improper or inappropriate food/formula choices or preparation

Psychosocial

Laboratory Values

NCP: Nutrition Assessment•Obtain, verify, interpret information•Data used might vary according to

setting, individual case, etc…•Questions to ask

▫Is there a problem?▫Define the problem?▫Is more information needed?

Tools Used in Nutrition Assessment• Growth

▫ Measurements▫ Growth charts▫ Absolute size (percentile)▫ Pattern▫ Body composition (water,

bone, muscle, fat)

• Intake▫ Food record/recall

analysis• Additional information

▫ Medical▫ Development▫ Social▫ Laboratory▫ Etc.

NCP: Nutrition Diagnosis

•Identification or labeling of problem that is within RD scope of practice to treat▫Examples:

Inadequate intake Inadequate growth

NCP: Intervention, Monitoring and Evaluation•Intervention

▫Etiology drives the intervention•Monitoring and Evaluation

PART 2 – Definition of Growth

Growth•Dynamic process • Increase in the physical size of the body as a

whole or any of its parts associated with increase in cell number and/or cell size

•Reflects changes in absolute size, mass, body composition

•A normal, healthy child grows at a genetically predetermined rate that can be compromised by imbalanced nutrient intake

Growth in the first 12 months•From birth to 1 year of age, normal

human infants triple their weight and increase their length by 50%.

•Growth in the first 4 months of life is the fastest of the whole lifespan - birthweight usually doubles by 4 months

•4-8 months is a time of transition to slower growth

•By 8 months growth patterns more like those of 2 year old than those of newborn.

Changes in Body Conformation

Weight Gain (g/d) in one-month increments – Girls and Boys

Age 10th percentile

50th percentile

90th percentile

Up to 1 month

16 18 26 30 36 42

1-2 months

20 25 29 35 39 46

2-3 months

14 18 23 26 32 36

4-5 months

13 14 16 17 20 21

5-6 months

11 12 14 15 18 19

Guo et al, 1991

Evaluating Growth: Adam

Evaluating Growth: Adam, cont’d

Rates of weight gain: Breastfed vs. Formula-fed

• Rates of gain for breastfed and formula fed infants during early months of life generally have been found to be similar although some reports have demonstrated greater gains by breastfed infants and others have shown greater gains by formula fed infants▫ Dewey, Pediatrics, 1992;89:1035▫ Nelson, Early Human Development, 1989;19:223.▫ Cole, Acta Paediatr, 2002;91:1296.

PART 3: How growth is evaluated

Do parents understand growth charts?•Ben-Joseph E, et al. Do parents understand

growth charts? A national, internet-based study. Pediatrics. 2009; 124(4):1100-09.

•n=1000 parents (US)•Completed internet survey about

awareness of, knowledge of, and attitudes toward growth monitoring and ability to interpret growth data

•Survey at: http://kidshealth.org/misc/surveys/GrowthChartSurvey.pdf

Chart 1

•Based on this point, how old is the child?

•How much does he weigh?

•What “percentile” is this child’s weight at?

Chart 1 - continued

• What does it mean that the child’s weight is at the 90th percentile?a. 90% of children are

heavierb. Child is heavier than

90% of othersc. Child is 90% of

recommended weightd. I am not suree. Other

Reference vs Standard

•Reference: a set of data used for normalizing measurements so that they can be manipulated statistically, grouped and compared with other sets of measurements. In principle, implies no value judgment and tells us nothing about optimal or satisfactory growth

•Standard: Implies a value judgment. In theory, standards are selected based on representing “optimal,” “normal,” or “goal”

Fetal/Neonatal Growth Charts

•Intrauterine charts▫Classification of newborn

AGA LGA SGA

•Postnatal Charts

Intrauterine/Fetal Growth Standards•Lubchenco•Gairdner•Babson/Benda•Fenton•Olsen

Fetal Growth Data

Fenton Chart

•Data Sets:▫Kramer, et al: 676,605 infants, 22-43 weeks▫Nicholson, et al: 376,000 Swedish infants

28-40 weeks▫Breeby, et al: OFC (N=29,090) and Length

(N=26,973), 22-40 weeks▫CDC Data

•Time period 1963-2001

Postnatal Growth Charts

•Accounts for initial weight loss•Dancis: Data 1948, very small sample size

in lowest weight group•Ehrenkranz: Pediatrics 1999:104:280

▫N=1660▫14-16 g/kg/d weight gain▫0.9 cm/week increase length▫0.35 cm/week increase OFC

Infant Growth Charts (References): Timeline• Stuart/Meredith

Growth Charts (1946-76)▫ Caucasian, Boston/Iowa

city, small sample size• NCHS growth charts

(1976-1978)▫ Cross sectional Data

from NHES, NHANES, and FELs

▫ CDC produced normalized version

▫ 1978 WHO recommended international use

• CDC (2000)▫ 5 cross sectional

nationally representative surveys between 1963-1995

▫ Included more breast fed infants

• WHO (2006)▫ Data from Brazil, Ghana,

India, Norway, Oman and US

▫ Multiethnic, affluent▫ Exclusive breastfeeding to

4 months▫ Solids according to

recommendations 6 months

▫ Continued breastfeeding to 12 months

Evolution: NCHS CDC ChartsNCHS infant data: Fels study CDC infant data: NHANES I, II, III

• Primarily formula-fed• Underrepresented groups:

largely Caucasian, middle class

• Intervals of measurements (q3 months from 3-36 months) may not define dynamic patterns during rapid growth phases

• Statistical smoothing procedures

• Standardized data collection methods

• Expanded sample • More breastfed infants• Exclusions

▫ VLBW infants▫ NHANES III weight

data for >6 year olds

Evolution: NCHS WHO Charts

• Released new growth standards April 2006▫ Assumed infants and

children grow similarly when needs are met.

• Concerns for CDC charts included:▫ Frequency of growth

measures during dynamic periods of infant growth

Compare the charts (<24 month olds)

CDC growth reference (2000)

WHO growth standard (2006)

Data sources Nat’l vital statistics (birthwts), PNSS, NHANES I, II, III (1971-1994)

MGRS longitudinal component (Brazil, Ghana, India, Norway, Oman, United States)

Data type Cross-sectional starting at age 2 mo, with mathematical modeling

Longitudinal: birth, 1, 2, 4, 6, 8 weeks; 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24 months

Sample size 4697 observations for 4697 children

18,973 observations for 882 children

Breastfeeding among infants in sample

~50% ever breastfed~33% breastfeeding at 3 mo

100% ever breastfed100% predominantly breastfeeding at 4 mo100% breastfeeding at 12 moComplementary foods introduced at mean age 5.4 mo

Source: MMWR, 2010; 59(No. RR-9):1-15.

Compare the charts (<24 month olds)

CDC growth reference (2000)

WHO growth standard (2006)

Exclusion criteria

VLBW (<1500 g) • Low socioeconomic status• Birth at altitude >1500 m• Birth at <37 wkor >42 wk• Multiple birth• Perinatal morbidities• Child health conditions

known to affect growth• Maternal smoking during

pregnancy or lactation• Breastfeeding for <12 mo• Complementary foods before

4 mo or after 6 mo• Wt-for-length >3 SD +/-

study median

Comparison of WHO and CDC Chart (weight-for-age)

Girls Boys

Source: MMWR, 2010; 59(No. RR-9):1-15.

Comparison of WHO and CDC Chart (stature-for-age)

Girls Boys

Source: MMWR, 2010; 59(No. RR-9):1-15.

Charts to Evaluate Growth of InfantsCDC Clinical Chartshttp://www.cdc.gov/growthcharts/

WHO Child Growth Standardshttp://www.who.int/childgrowth/en

• Sex-specific▫ Weight-for-age▫ Length-for-age▫ Weight-for-length▫ Head circumference-for-

age• Choice between outer

limits at 3rd and 97th percentiles, or 5th and 95th

• Sex-specific▫ Weight-for-age▫ Length-for-age▫ Weight-for-length▫ Head circumference-for-

age▫ On WHO site: BMI,

other measures• Outer limits at 2nd and 98th

percentiles

Differences between WHO and CDC infant charts• WHO mean > CDC mean birth to 6 months• “Healthy breastfed infants track weight-for-age

along WHO but falter on CDC”• Cross at 6 months and WHO mean < 6 months• On the CDC chart, children appear heavier and

shorter• On the WHO chart, children appear taller• WHO charts:

▫Higher estimate of overweight▫Lower estimates of underweight,

undernutrition

CDC Recommendations for infant growth chartsExpert Panel (NIH, AAP) to review scientific evidence. Recommendations:•WHO charts from birth to 24 months•CDC charts for >24 months•As a screen, 2rd and 98th percentile on WHO corresponds to 5thand 95th on CDC•Clinicians should be aware that fewer individuals will be screened as “underweight” and more as “overweight” using WHO•For more, see http://www.cdc.gov/growthcharts

Controversies/Issues•Screen vs. assessment•Standard vs. reference•Typical vs. ideal growth•Environmental influence•Variety of diets may result in acceptable

growth and nutrition status•Normal population diversity

Plot individuals on both CDC and WHO. Does your assessment change? • Absolute size vs. pattern

Carl

Carl – absolute size vs. pattern

PART 4: Problems with Growth• Underweight• Overweight• Failure to Grow• “Overfat”

Screening Assessment• Screening identifies

nutritional risk and/or need for further assessment.

Assessment:•Collect data•Interpret data

▫ Link information▫ Compare to references,

standards, expectations▫ Ask questions

Interpretation: Asking Questions• Is there a problem?• Was there a problem?• Does information

make sense?• What are goals and

expectations?• What is etiology of the

problem?

Overweight

•Weight in infancy associated with weight in childhood▫Crossing percentiles (upward) in infancy is

associated with ↑d OR of childhood obesity (Taveras, 2011)

▫Children in upper tertile had higher risk of childhood obesity than children in lower tertile (Andersen, 2012)

•Appropriate screening tool, intervention not clear; Beth’s take-home message: keep feeding babies

Undernutrition

•↓ weight, no effect on length low weight-for-length

•↓ ↓ weight ↓ length or height eventually may appear proportionate

Failure to Grow, Failure to Thrive• Failure to gain weight or grow at expected rates

▫Weight-for-age <5th %ile▫Weight-for-length <5th %ile▫Decreased growth velocity (decrease over 2 SD

over 3-6 months)▫<80% ideal body weight

• 1-5% tertiary hospital admissions for <1 year olds

• Prevalence varies▫5-10% <3 years of age▫Some populations at higher risk

Failure to Grow

•Inadequate intake▫Not enough food offered: Food insecurity,

lack of knowledge of child’s needs▫Not enough food consumed: Oral-motor

dysfunction, behavioral feeding problems▫Emesis

•Malabsorption•Increased metabolic demand

Figure 5: Proposed algorithm[s] for identification and assessment of possible undernutrition in infancy [and childhood] (White, 2012)

Potential Pitfalls in Growth Assessment•Excuses•Assumptions•Faulty reasoning•Incorrect or

inaccurate information

•Not evidence-based

•Biased

Process

•Identify Problem or risk

•Identify Etiology•Determine intervention

•Monitor and Reevaluate