introduction to infant feeding: growth and assessment

Introduction to Infant Feeding: Growth and Assessment

Growth

Fetal Growth from 25-40 weeks GA

Weight increases 4-fold Length and OFC increase 2-fold

Determinants of fetal growth

Genetics Maternal/paternal genes, race, sex

estimated to account for 20% of variance in birth weight

Environmental factors

Body Composition BMI and percentage of body weight

made up of fat increase rapidly during the first months of life Fat accounts for 0.5% of body weight

at the fifth month of fetal growth and 16% at term.

3rd trimester: increase from 1-3% of body weight to 10-16% of body weight at term

After birth, fat accumulates rapidly until approximately 9 months of age

Minerals

Two-thirds of mineral content of full-term newborn is accummulated in the last trimester of pregnancy.

Age-related changes in body composition. (Reprinted by permission ofMosby Year Book. Heird WC, Driscoll JM, Schullinger JN, et al.Intravenous alimentation in pediatric patients. J Pediatr 80:351, 1972.)

Energy Reserves

Birthweight Non protein kcal Total kcal

500 50 225

800 grams 125 435

1000 grams 165 600

1500 425 1120

2000 1050 1975

3500 4175 5924

Environmental factors Maternal health Nutrition

Glucose, fatty acids, amino acids for tissue deposition and fuel for oxidative purposes

Ability of maternal-placental system to transfer nutrients to fetus

Endocrine environment E.g. LGA infant:

glucose-insulin-growth factors

GROWTH IN 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.

Weight Gain in Grams per Day in One Month Increments - Girls

Age 10th

percentile50th

percentile90th

percentileUp to 1month

16 26 36

1-2months

20 29 39

2-3months

14 23 32

4-5months

13 16 20

5-6months

11 14 18

Guo et al., J Peds. 1991

Weight Gain in Grams per Day in One Month Increments - Boys

Age 10th

percentile50th

percentile90th

percentileUp to 1month

18 30 42

1-2months

25 35 46

2-3months

18 26 36

3-4months

16 20 24

4-5months

14 17 21

5-6months

12 15 19

Guo et al., J Peds. 1991

Body Composition BMI and percentage of body weight

made up of fat increase rapidly during the first months of life Fat accounts for 0.5% of body weight

at the fifth month of fetal growth and 16% at term.

After birth, fat accumulates rapidly until approximately 9 months of age

Individual Growth Patterns

Weight and length at term appear to be primarily determined by nongenetic maternal factors

Birth weigh and birth length weakly correlate with subsequent weight and length values

Individual Growth Patterns, cont.

African American males and females are smaller than whites at birth, but they grow more rapidly during the first 2 years

Patterns of growth in breastfed infants are different from formula fed infants

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

Weight gain of Breast fed vs bottle fedinfants: 8-112 days of age (g/d)

Breast fed Bottle fed

Male 29.8 + 5.8 32.2 + 5.6

Female 26.2 + 5.6 27.5 + 4.9

Nelson et al Early Human Development 19:223 1989

Factors to Consider

Constellation of Factors Affecting theUnique Needs of the Preterm Infant

Characteristics Nutrient needs Goals Growth

expectations Outcomes that

Impact growth and nutritional needs

Assessment

Assessment

Screening identifies nutritional risk Nutrition Assessment

Uses information gathered in screening Adds more in depth, comprehensive

data Interprets data Develops care plan Reassess

Assessment

Screening identifies nutritional risk Nutrition Assessment

Uses information gathered in screening Adds more in depth, comprehensive

data Interprets data Develops care plan Reassess

Nutrition Screening: Purpose

To identify individuals who appear to have or be at risk for nutrition problems

To identify individuals who require further assessment or evaluation

Screening: Definition

Process of identifying characteristics known to be associated with nutrition problems ASPEN, Nutri in Clin Practice 1996 (5):217-228

Simplest level of nutritional care (level 1) Baer et al, J Am Diet Assoc 1997 (10) S2:107-115

Goals of Nutrition Assessment

To collect information necessary to document adequacy of nutritional status or identify deficits

To develop a nutritional care plan that is realistic and within family context

To establish an appropriate plan for monitoring and/or reassessment

Information Collected

Growth Dietary Medical history Diagnosis Feeding and developmental information Psychosocial and environmental information Clinical information and appearance (hair,

skin, nails, eyes) Other (anthropometrics, laboratory)

Interpretation Linking

information collected with:

Goals/expectations Reference

data/standards Evidence individual

Asking questions

Challenges

Nutrient needs influenced by:genetics, activity, body composition, medical conditions and medications

Alterations in growth and measures of growthgenetics, body composition, physical limitations

Challenges

Information Availability,

sufficiency, accuracy Interpretation

Goals, expectation, “does it make sense”

Questions What are goals and

expectations, “does it make sense”

Considerations Growth in infancy Physiology of infancy

GI Renal

Infant Development Nutrient requirements

* Recommendations Milk based feedings/Infant formulas Timing of complementary foods

What are families actually doing? Specific issues of safety and oral health

Challenges: Recommendations for populations v.s individual

Challenges

Identification of etiology Weighing risk vs benefit Supportive of:

Family Individual Development/temperament

Growth Assessment

Growth Concerns

Underweight

Short stature

Overweight

A variety of growth references were developed and and used

in the U.S. since the early 1900’s

Growth references: timeline Stuart/Meredith

Growth Charts (1946-76)

Caucasian, Boston/Iowa city, small sample size

NCHS growth charts (1976-1978)

NCHS AAP/MCHB study

group Used cross sectional

data from NHES, NHANES, and FELs (infant)

CDC produced normalized version

1978 WHO recommended international use

Growth reference timeline: continued

2000 CDC growth charts: revision of NCHS growth charts

2006 WHO released new international growth standards

Assessment of Growth

Growth Charts CDC/NCHS

http://www.cdc.gov/growthcharts/ World Health Organization

http://www.who.int/childgrowth/en

Specialized growth charts Patterns, rates, velocity

NCHS growth charts: Concerns Infant data: Fels study

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 proceedures

CDC Growth charts: 2000

Based on 5 cross sectional nationally representative surveys between 1963 and 1995

Included more breastfed infants

CDC/NCHS Growth Charts

Data from previous NCHS charts came from private study of primarily white, formula-fed, middle-class infants from southwestern Ohio before 1975

Newer charts have more representative data (some breastfeed and ethnic diversity) from NHANES and use more sophisticated smoothing techniques

16 new charts provided by gender and age

CDC Growth Charts (compared to older NCHS

Standardized data collection methods

Expanded sample Exclusions

VLBW infants NHANES III weight data for >6 year

olds

CDC Growth Charts (compared to older NCHS

Standardized data collection methods

Expanded sample Exclusions

VLBW infants NHANES III weight data for >6 year

olds

CDC/NCHS Growth Charts

Clinical charts for infancy for girls and boys: weight length weight for length OFC

Choice between outer limits at 3rd and 97th or 5th and 95th percentiles

Adam

Adam

Carl

WHO Child Growth Standards

Released new growth standards April 2006 Assumed that infants and children

between birth and 5 years grow similarly when needs are met.

Concerns for CDC charts included: Frequency of growth measures during

dynamic periods of infant growth Statistical methods

WHO growth charts

Data from Brazil, Ghana, India, Norway, Oman and USA

Multiethnic, affluent Exclusive breastfeeding to 4 months Solids according to recommendations

6 months Continued breastfeeding to 12 months

WHO growth charts

Full term low birthweight infants not excluded

Birth to 2 years N 1743 ----- 882

2-5 years N 6669

WHO v.s. CDC

Infancy WHO mean > CDC mean birth-6

months “healthy breastfed infants track

weight/age along WHO but falter on CDC”

Cross at 6 months and WHO mean < 6months

WHO v.s. CDC CDC

Heavier, shorter WHO

taller WHO

Higher estimates of overweight Lower estimates of underweight,

undernutrition

Dietary Information

Family Food Usage 24 hour recall Diet history 3-7 day food record or diary Food frequency Other Information

Food preparation, history, feeding observation, feeding problems, likes/dislikes, feeding environment

Dietary Information

Evaluate fluid, macro and micronutrients (energy, protein, vitamin D, Calcium/phosphorus, iron, other)

Compare intake to: DRI ? Condition or syndrome specific Equations

Link intake to: Additional information collected in

individual assessment process

Comparison of individual intake data to a reference or estimate of nutrient needs

DRI: Dietary Reference Intakes

periodically revised recommendations (or guidelines) of the National Academy of Sciences

quantitative estimates of nutrient intakes for planning and assessing diets for healthy people

AI: Adequate Intake

UL: Tolerable Upper Intake Level

EER: Estimated Energy Requirement

Approaches to Estimating Nutrient Requirements

Direct experimental evidence (ie protein and amino acids)

Extrapolation from experimental evidence relating to human subjects of other age groups or animal models

ie thiamin--related to energy intake .3-.5 mg/1000 kcal Breast milk as gold standard (average [] X usual intake) Metabolic balance studies (ie protein, minerals) Clinical Observation (eg: manufacturing errors B6, Cl) Factorial approach Population studies

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?

Contributing Factors

Inadequate IntakeFluid, energy

MedicalBPD, reflux, frequent illness

Feeding relationshipStress, history

Psychosocial

Intervention Identify etiology Identify contributing

factors Support feeding

relationship Consider

psychosocial factors, family choice and input

Weigh risk v.s. benefit

Weighing Risks and Benefits