L6 Infant Growth and Development Flashcards
Intra-Uterine Growth
Embryonic and fetal growth - assessed by birthweight
Gestational age
Post menstrual age: number of weeks + days since 1st day of last menstrual period
Full term
38-42 weeks post menstrual age
Pre term
less than 37 weeks post menstrual age
Low birth weight
< 2500 g at delivery
What is assessed at delivery?
Measure the length, weight, head circumference. Is assessed using growth charts and provides information about patterns of intra-uterine growth.
What is the percentile of a SGA baby?
<10th percentile - weight per age
What is the percentile for AGA baby?
10 - 90th percentile
What is the precentile for a LGA baby?
> 90th percentile
Why do we use the birth weight classification?
It is a method of describing the likelihood of adverse outcomes.
Different issues with the different classifications.
What are the infant, placental and maternal causes for a SGA baby?
Infant: congenital anomalies, genetic conditions, congenital infections.
Placental: small placenta, inadequate placental blood flow
Maternal (environmental): smoking, drugs, alcohol, under nutrition.
What are the issues associated with a SGA infant?
Hypoglycemia due to lack of glycogen stores during gestation, inability to maintain temperature from lack of body fat, decreased immune competence, and neurological and behavioral problems
What are the infant and maternal causes of a LGA infant?
Infant: genetic
Maternal: uncontrolled/poorly controlled diabetes (infant with a diabetic mother is at an increased risk of diabetes ??)
What are some issued associated with a LGA infant?
- Birth injury
- hypoglycemia, hypocalcemia, respiratory, cardiac problems, congenital malformation (3-4X risk)
What is congenital malformation?
When there is too much glucose available for the fetus. Development may favour hypertrophy rather than hyperplasia.
Why do we monitor growth (X5)?
- To help reinforce healthy eating patterns
- Tool for nutrition and health evaluation
- Initiate further assessment in case of unusual growth patterns
- “teachable moments” with caregivers
- context for regular contact with primary health care services
How long do we use growth charts for?
What are they measuring?
birth to 2 years (CDC growth charts only)
- weight for age
- length for age
- head circumference for age
- weight for length
What is the difference between the CDC Growth Charts and the WHO Child Growth Standards?
CDC:
- measures how infants growth within a population. Growth is assessed relative to others in the population.
- reference group is a large group of infants in the USA
- includes breast fed and formula fed
- compares growth to other infants
WHO Standards:
- sets the standards of the optimal growth in infants
- growth is assessed relative to optimal
- identifies inadequate or excessive growth
- international growth charts
- longitudinal follow up of children in 6 countries
- infants included in data were selective (healthy, living in favorable conditions, breastfed, non-smoker mothers)
Why did WHO choose to use only breast fed?
Breast is best
Breast fed infants have a slower rate of gain in the first year compared to formula fed.
What ages if the WHO Child Growth Standard for?
birth to 5 years
For a growth chart measuring weight for length, what is horizontal axis and what is vertical?
horizontal (X) = length
vertical (Y) = weight
What is the percentile?
Proportion of population that is below a specific value
What does birthweight reflect the expected growth patterns and how do SGA and LGA infants differ in growth patterns?
- prenatal growth factors, postnatal growth dependent on different genetic potential.
- LGA infants will have a slower rate of increase in the percentile than SGA infants.
What indications from the growth patterns should a health care professional follow up on?
What should they consider?
- flat growth line
- sharp increase or decrease
- below the 3rd percentile
- above 97th percentile for weight for length
Birthweigth, previous growth pattern, gestational age, genetics, type of feeding, presence of a condition
What are the expected growth patterns for an infant at about 4 months and about 1 year?
4 months should double birth weight
triple birth weight by 1 year
What is a Fenton Growth Chart?
Same as a regular growth chart but is used for preterm infants and uses data starting at 22 weeks gestational age. Should switch to normal full term charts when infant is within the gestational and measurement ranges using corrected age.
How do you correct an age in weeks for a premature infant’s growth chart?
Current age (weeks since birth) minus (40 weeks - gestational age at birth in weeks)
When is the GIT formed?
prior to third trimester
In the 3rd trimester what prepares the GIT for nutrients?
Ingestion of amniotic fluid
When is GI motility mostly developed?
Early infancy
What gives an infant the ability to digest components of breastmilk efficiently?
Lactate activity increases rapidly with feeding.
Why do infants have poor starch digestion?
Low pancreatic amylase
What types of fats are better absorbed?
Short and medium chains
What is the glomerular filtration rate?
At what rate do infants have this ability at birth, 1 year, and 3 years?
The rate at which electrolytes, water and waste products are transferred from the circulation into the kidney.
birth - 30%
1 year - 70%
3 years - 100%
What is the RSL (renal solute load)?
What is normal?
How does it increase?
Electrolytes and urea to be excreted. Higher RSL means more water for excretion.
normal - low RSL
With higher protein
What are the protective functions of the GIT?
- development of the mucosal gut barrier
- protective mechanisms: gastric barrier, proteolysis, peristalsis, factors in breast milk, mucosal coat and microvillus membrane, antibodies (IgG, sIgA)
How does a metabolic change occur at birth in regards to glucose?
Constant supply of glucose is lost. Must now regulate its own glucose. Plasma glucose decreases at birth so there is a reduction in insulin and increase in glucagon to break down glycogen, and encourage lipolyisis and gluconeogenesis.
This is why proper glycogen and TG synthesis and storage during the 3rd trimester is important.
When does flexoin develop in a newborn?
28-40 weeks
What is the sleep cycle of a newborn?
at birth is awake for about 30-60 min
after is asleep for 80% and 20% active, inactive, or crying
what is an APGAR score?
determines is infant needs more medical attention Appearance (skin colour) Pulse (heart rate) Grimace (response to stimulation) Activity (flexion) Respiration (respiratory effort)
What are the primitive reflexes that gradually disappear with maturity?
Rooting: head turning toward stroked face
Sucking: reflexive (not voluntary)
Moro: “startle” reflex - arms move outward, then toward body
Head lag/step: head movement during pull to sit, stepping movement when help upright
What reflexes are needed to milk feed?
grasp nipple, suck, swallow, breathe
What reflexes are needed for baby food?
tongue movement to move food back and upright posture/head control
What muscle coordination is needed for self feeding?
- grasp, hand to mouth
- tongue movement to side
- upright posture/head control
What muscle coordination is needed for drinking from a cup?
- hands & object to mouth
- tilt head & cup backward
- control free flowing liquid
What muscle coordination is needed to table feed?
- collect particles of food in bolus for swallowing
- to push food to side of gums/teeth for chewing
When do most developmental milestones occur?
0 - 6 months
At 4 - 6 months, what kind of development should the child have?
Grasps objects, improve head control, some vocalization
At 6 months what kind of development should the child have?
Transfer objects hand to hand, hand to mouth, sits with support, 1st teeth, expresses food preferences
At 7-8 months what kind of development should the child have?
Sits independently, more vocalization
At 9 months what kind of development should the child have?
pincer grasp, cruising on furniture
At 12 -15 months what kind of development should the child have?
walking, words, 1st molars
