Infancy Growth and Development (Video Notes)

Physical Growth

• Scope: Growth and development from 1 month to 1 year (Infancy). Rapid physical growth is a hallmark of this period and is critical for both physical and emotional development.
• Rapid growth in infancy:
  • Birth weight typically triples by 10–12 months; birth length increases by about 50% by the same period.
  • Expressed numerically: if initial birth weight is $W0$ and birth length is $L0$, then approximately:
  • W{12m} \approx 3W0
  • L{12m} \approx 1.5L0
• Weight gain by months:
  • Birth to 4 months: rac{3}{4}\ ext{kg/month}
  • 5 to 8 months: \frac{1}{2}\ ext{kg/month}
  • 9 to 12 months: \frac{1}{4}\ ext{kg/month}
  • Note: The infant will double birth weight by 4–5 months and triple it by 10–12 months.
• Height/Length growth rates:
  • 1st 3 months: length increases about 3\ \text{cm/month}
  • 4–6 months: about 2\ \text{cm/month}
  • 7–12 months: about 1.5\ \text{cm/month}
• Head circumference (HC):
  • 1st 3 months: HC increases about 2\ \text{cm/month}
  • Next 9 months: about 0.5\ \text{cm/month}
  • Fontanels:
  • Posterior fontanel closes by 6-8\ weeks of age
  • Anterior fontanel closes by 12-18\ months of age
• Chest circumference vs head:
  • At birth, chest circumference is about 2 cm smaller than head circumference.
  • By the end of the 1st year, chest circumference approximates head circumference: C{chest}(12m) \approx C{head}(12m)
• Physiological growth signs (neonatal vitals):
  • Pulse: 110\text{ to }160\ \text{beats/min} to 100\text{ to }120\ \text{beats/min}
  • Respiratory rate: 30\text{ to }60\ \text{breaths/min} to 20\text{ to }30\ \text{breaths/min}
  • Respirations are primarily nasal (breathing through the nose)
  • Blood pressure: 80/40\ \text{mmHg} \text{ to } 100/60\ \text{mmHg}
• Teeth (Infancy dentition):
  • Teeth are called "milky teeth", "deciduous teeth", or "temporary teeth".
  • The first baby tooth (typically a central incisor) usually erupts around 6\ \text{months}, followed by a new one monthly.
  • Fluoride supplementation is recommended starting at 6\ months of age (AAP, 2017).
• Eruption pattern of deciduous teeth:
  • Upper teeth:
  • Central incisor: 8{-12} \text{ months}
  • Lateral incisor: 9{-13} \text{ months}
  • Cuspid (canine): 16{-22} \text{ months}
  • First molar: 13{-19} \text{ months}
  • Second molar: 25{-33} \text{ months}
  • Lower teeth:
  • Central incisor: 6{-10} \text{ months}
  • Lateral incisor: 10{-16} \text{ months}
  • Cuspid (canine): 17{-23} \text{ months}
  • First molar: 14{-18} \text{ months}
  • Second molar: 23{-31} \text{ months}
• Key takeaways: infancy involves synchronized physical growth (weight, length, HC, chest), dentition onset, and early nutrition needs.

Motor Development

• Core concept: motor development follows cephalocaudal (head-to-toe) progression and gross-to-fine motor development.
• Gross motor definition:
  • Gross motor: ability to perform large body movements (e.g., sitting, standing, walking).
  • Fine motor: ability to coordinate hand movements (e.g., grasp, pincer grip).
• Gross Motor Development: four primary positions used to describe progression – ventral suspension, prone, sitting, standing.

Gross Motor Development: Ventral Suspension

• Description: infant held in midair on a horizontal plane, supported by a hand under the abdomen.
• Early behavior:
  • Newborns often have heads that hang down with limited control.
  • 1 month: head briefly lifts, then drops.
  • 2 months: head held in same plane as body (improved neck control).
  • 3 months: head lifted well above the plane of the body in ventral suspension.
• Reflexes related:
  • Landau reflex develops at around 3 months.
  • Parachute reaction appears around 9 months.

Gross Motor Development: Prone Position

• Lying on the stomach; key milestones include neck-righting reflex development and sideways rolling when lifting the head.

Gross Motor Development: Crawling/Creeping

• By 9 months: infanct can creep from the prone position (abdomen off the floor; moves hands and knees alternately with knees on the floor).

Gross Motor Development: Sitting Position

• Initially, the back is rounded and head control is momentary.
• By about 8 months: infant sits independently.

Gross Motor Development: Head Lag and Standing

• Head lag:
  • Present until about 1 month of age.
• Standing/Reflexes:
  • Stepping reflex present at 1 month; fades by 4 months.
  • Tonic neck reflex (fencing posture) around 5 months: head turns to one side; opposite arm straightens and the other arm bends.
  • By 11 months: infant may cruise along walls.

Gross Motor Development: Walking Milestones

• First independent steps between 8\text{ and }15\ months.
• By about 22\ months, many children walk; this is within the normal developmental window.

Fine Motor Development

• 1–2 months: grasp reflex (palmar and plantar).
• 3 months: infant reaches for attractive objects.
• 4 months: infant brings hands together and pulls at their clothes.
• 6–10 months: scooping or raking to grasp large objects (not a precise pincher).
• 10 months: emergence of the pincer grasp (thumb and index finger together) to pick up small objects.

Emotional Development

• The newborn expresses emotion mainly through crying (hunger, pain, discomfort).
• Emotions are unstable and rapidly shift between crying and laughter.
• Emergence of affection toward family members appears early.
• By 10 months, several beginning recognizable emotions emerge (anger, sadness, pleasure, jealousy, anxiety, affection).
• By 12 months, these emotions are more clearly distinguishable.

Social Development

• The infant learns that crying brings attention.
• Smiles in response to the smile of others.
• Stranger anxiety develops around 8 months.
• Responds to name.
• Erikson’s theory: the infant develops a sense of trust through consistent caregiving and reliable interactions, particularly during feeding and relief of basic needs.
• Trust is built through warm, responsive caregiver interactions; limited number of caregivers is beneficial.

Cognitive Development

• 1 month: Reflex activity; minimal differentiation from the environment.
• 3 months: Primary circular reactions; exploring objects by grasping them or mouthing them.
• 6 months: Secondary circular reactions; actions produce effects (e.g., reaching for a mobile, hitting it, and watching it move) and realizing it was their hand that caused it.
• 10 months: Object permanence; ongoing exploration and anticipation of outcomes (peek-a-boo).
• 12 months: Deliberate reproduction of events; exploring cause-and-effect by dropping objects from high surfaces and watching where they fall or roll.

Language Development

• 1 month: Cooing (dovelike sounds).
• 2 months: Discrimination of cries (e.g., hungry, wet, lonely).
• 3 months: Laughs out loud.
• 4 months: Highly vocal; cooing, babbling, and gurgling when spoken to; laughs out loud.
• 5 months: Emergence of vowel sounds (e.g., “goo-goo,” “gah-gah”).
• 6 months: Imitates sounds (coughs, says “Oh”).
• 7 months: Vowel sounds more developed (e.g., “oh-oh,” “ah-ah,” “oo-oo”).
• 9 months: First words often emerge (e.g., “da-da” or “baba”).
• 10 months: Another meaningful word (e.g., “bye-bye” or “no”).
• 12 months: Usually can say two words in addition to “mama” and “dada” with meaning.

Play Development

• 1 month: Prefers watching parents’ faces or a mobile over the crib.
• 2 months: Light rattles, mobiles, cradle gyms;
• 3 months: Small blocks or small rattles.
• 4 months: Rolling over; sheet activity.
• 5 months: Plastic rings, blocks, squeeze toys, clothespins, rattles, plastic keys.
• 6 months: Bath toys such as rubber ducks or plastic boats.
• 7 months: Transferrable toys, blocks, rattles, small keys that transfer easily.
• 8 months and beyond: Textures become important (velvet, fur, fuzzy/smooth/rough items); 9 months: toys that nest or fit together; 10 months: peek-a-boo, hand games, pat-a-cat; 11 months: cruising on low tables; 12 months: containers and pull-toy play.

Development of Senses

• Vision milestones:
  • 1 month: Focus on midline objects; fixed gaze at faces.
  • 2 months: Binocular vision achieved; follows moving objects.
  • 3 months: Follows objects across the midline; hand regard.
  • 4 months: Recognizes familiar objects; follows movements.
  • 6 months: Organized depth perception; improved reach.
  • 7 months: Recognizes mirror image; transfers toys.
  • 10 months: Begins understanding object permanence.
• Hearing milestones:
  • Birth to 1 month: Reacts to distinctive sounds.
  • 2 months: Stops activity in response to spoken words.
  • 3 months: Turns head to locate sounds.
  • 4 months: Locates sounds downward and sideways.
  • 6 months: Locates sounds above.
  • 10 months: Recognizes name; locates sounds in all directions.
  • 12 months: Can locate sounds accurately; understands a few words.
• Auditory stimulation recommendations:
  • Use soothing sounds and familiar voices.
  • Daily reading supports language development.
• Touch, Taste, Smell:
  • Touch: skin-to-skin contact is important; clothes should be soft and comfortable; diapers should be dry.
  • Taste: solid foods begin around 6 months; feeding fosters trust.
  • Smell: infants react to odors; familiar smells (e.g., breast milk) are comforting.

Red Flags in Infant Development

• Inability to sit alone by 9 months.
• Inability to transfer objects from hand to hand by 1 year.
• Abnormal pincer grasp or grasp by 15 months.
• Inability to walk alone by 18 months.
• Failure to speak recognizable words by 2 years.

Nursing Role in Health Promotion

• Foundational concept: Trust vs. Mistrust (Erikson).
• Consistent caregiving and predictable routines help develop trust.
• Important to limit the number of caregivers to ensure reliable attachment.
• Encouraging active interaction and caregiver involvement during feeding and other care promotes trust and bonding.
• Safety and health promotion:
  • Aspiration prevention: avoid small, round objects; avoid propping bottles.

Safety and Injury Prevention in Infancy

• Fall prevention:
  • Never leave infants unattended on raised surfaces.
  • Parents should be vigilant as infants begin turning over around 2 months.
  • Lower crib mattresses and ensure side rails are secure.
  • Crib safety: raise crib sides; avoid gaps between mattress and headboard; cords out of reach.
• Car safety:
  • Use rear-facing car seats in the back seat until at least age 2 or until the child meets the maximum height/weight for the seat.
• Childproofing:
  • Check for lead paint; cover electrical outlets; install safety gates.
  • Remove hazardous substances; secure furniture.
• Safety with siblings:
  • Older siblings under age 5 may not be reliable caregivers; parental supervision and safety reminders are necessary.
• Bathing and swimming safety:
  • Never leave an infant unattended in a tub.
  • Exercise caution with baby swim programs.
  • Risks include hypothermia, exposure to microorganisms, and potential lung damage.

Nutrition and Feeding Guidance

• Nutritional health:
  • Breastfeeding is recommended for the first 6 months.
  • If possible, continue breastfeeding through the first year.
  • Formula should be iron-fortified if breastfeeding isn’t options.
  • Solid foods should start at about 6 months.
  • Begin with iron-fortified cereal, then introduce vegetables, fruits, and meats in a gradual sequence.