Chapter 4: physical and cognitive development in the first two years Flashcards
Average size of newborn
Appearance of newborn
- Average neonate is: 51cm long and 3.4kg
- At birth may have red skin and be covered in vernix (i.e., oily protection against infection) and lanugo (i.e., fuzzy prenatal hair)
- Head may be elongated due to pressure of birth canal
- Fontanelles or gaps in the bones of the head – “soft spots”
APGAR scale
Apgar scale: consists of ratings to calculate the baby’s heart rate, breathing effort, muscle tone, skin colour and reflex irritability.
- 0-2 score is given to each characteristics and the test is taken after they emerge and at five minutes.
- The test is taken twice as some babies find it difficult to adjust to their environment.
- A rating of 7 or above indicates the baby is in a healthy condition.
Central nervous system
Size of brain at birth and then at 2 years
Myelin
- Brain and nerve cells of spinal cord
- Coordination and control of perception and motor responses
- At birth, brain is c. 25% of adult weight
- By 2yrs, grown to 75% of adult weight
- Growth of neurons and connecting fibres
- Connections become myelinated (the coating of neural fibres with an insulating fatty sheath called myelin, which speeds the efficiency of message transfe)
Sleep patterns of infants
• Newborns sleep an average 16hrs per day
- Patterns change over time
- By 6mths average of 13 – 14hrs per day
- By 24mths average of 11 – 12hrs per day
• Adults average of 6 – 8hrs per day
SIDS
Risks
- Sudden and unexplained death of apparently healthy infant
- Leading cause of death in infants who survive first few weeks after delivery
- Most prolific between 2 – 4mths
- Unsure of cause– could be a combination of factors including underlying biological defect; gene mutations of heart; defects in brain stem regulating breathing, heartbeat, body temperature, and arousal
- Risks include sleeping on stomach, sleeping on soft surfaces, passive smoking, mother smoking when pregnant, baby being too hot or too cold
Acuity
keenness or fineness of discrimination
Visual Acuity
• At birth, infants have vision but lack acuity
- Objects often blurry, even at 6m
- Better at tracking moving objects
- Improves steadily during infancy
• Some evidence that infants respond preferentially to face-like patterns
Auditory Acuity
- Ability to hear is present at birth for most infants
- Moro reflex - startle response to loud sound
- Infants prefer complex sounds (noise and
voice)
• At a few days old can differentiate between:
- 2 and 3 syllables
- Emotional tones in language
- Ascending and descending tone
Early Human Reflexes
- tonic neck reflex (fencing)
- rooting
- babinski (toe flare)
- moro (noise)
- grasping/ darwinian
Motor skills
Gross
Fine
voluntary movements of the body or parts of the body
- Gross (i.e., movement of large muscles of arms, legs, and torso)
- Fine (i.e., movement of small muscles such as fingers, toes)
2 trends of motor skills
Cephalocaudal
Proximodistal
- Cephalocaudal (head to tail)
- Head larger and more developed compared to body
- Use upper parts of body before lower parts
- Proximodistal (near to far)
- Centre of body outwards
- E.g., head and trunk before arms and legs, hands and feet, then lastly fingers and toes
Motor development screening
-
Brazelton Neonatal Behavioural Assessment Scale (NBAS)
- Motor organisation; reflexes; state changes; attention and interactive capacity; CNS stability
- Up to 2mths
-
Bayley Scales of Infant Development
- Measures motor skills (fine and gross) and mental ability (memory, senses, perception, etc.)
- 1mth – 3.5yrs
-
Denver Developmental Screening Test
- Motor, social/personal, and language skills
• Up to 6yrs
Nutrition during first two years
Poor nutrition
- Western diets can sometimes be low in vitamins A and C ( difficulties in motor ability) and iron ( deficits in cognitive performance)
-
Malnutrition
- Kwashiorkor
- Marasmus
- Severe learning and behaviour effects
-
Over-nutrition (excess calories/nutrients)
- Unhealthy food preferences
- Food often used as reward
• Moderate overweight not a medical concern in infants
Impairments in Growth: Low Birth-Weight
- Weighing less than 2.5kg; very low birth-weight – less than 1.5kg
- Maternal traits that increase risk: maternal malnourishment, smoking, alcohol, drugs during pregnancy, teenage or low SES mothers
- Small-for-gestational age more problematic than preterm
- Interventions include incubators, gentle stimulation and ‘kangaroo care’