Nutrition Through the Lifecycle: Infant Nutrition

Infant Mortality

  • Definition: Measure of infant deaths within the first year per 1,000 live births.
  • Significance: Indicator of a nation’s health and well-being.
  • Current US Status: Ranks below other wealthy countries; reported rate: 5.96/1,000 in 2014.
  • Top Causes:
    • Birth defects
    • Low birth weight/preterm births
    • Sudden infant death syndrome (SIDS)
  • Role of Nutrition: Critical factor influencing infant mortality.

Assessing Newborn Health

  • Key Measures: Birthweight and gestational age.

    • Full-term: 37 to 42 weeks
    • Weight Guidelines:
    • Normal: 2500-3800 grams (5.5 - 8.5 lbs)
    • Low Birthweight (LBW): <2500 grams
    • Very Low Birthweight: <1500 grams
    • Extremely Low Birthweight: <1000 grams

  • Growth Assessments: Include gestational age, birthweight, length, head circumference.

    • Percentiles:
    • Appropriate for gestational age (AGA): 10th - 89th percentile
    • Small for gestational age (SGA - <10th percentile)
    • Large for gestational age (LGA - >90th percentile)
    • Intrauterine growth retardation (IUGR)

  • Growth Data Interpretation: Uses charts for tracking weight, length, and head circumference.

    • Warning Signs: Failure to increase weight/length, rapid changes in percentiles.

Newborn Reflexes

  • Key Reflexes:
    • Babinski, Blink, Moro, Palmar, Rooting, Stepping, Sucking, Withdrawal.
    • Each reflex has developmental significance, e.g., rooting helps find the nipple, while the Moro reflex may prevent falling.

Cognitive Development

  • Influenced by:
    • Severe, acute malnutrition
    • Chronic undernutrition
    • Iron and iodine deficiencies
    • Environmental interactions

Digestive System Development

  • Fetus gets amniotic fluid providing early intestinal growth stimulation.
  • At birth, infants can digest fats, proteins, and simple sugars; issues may include:
    • Gastroesophageal reflux (GER), diarrhea, constipation.
  • Gut Development: Gut microbiome begins formation pre-birth, influenced by breastfeeding.

Feeding During Infancy

  • Stomach Capacity Development:

    • Day 1: 5-7 mL (size of shooter marble)
    • Day 3: 22-27 mL (ping pong ball)
    • Day 10: 60-81 mL (extra-large chicken egg)

  • **Feeding Recommendations: **

    • Exclusive breastfeeding for 6 months; continue to 1 year.
    • Formula options include cow's milk-based, soy-based, hydrolyzed formulas (for allergies).

  • Cow's Milk-Based Formula:

    • Recommended when breastfeeding is not an option; iron-fortified.

Development of Feeding Skills

  • Innate Reflexes: Infants are born with reflexes to help regulate food intake (e.g., sucking, swallowing).

  • Developmental progression includes:

    • Birth - 5 months: Primary reflexes for feeding.
    • 6 - 12 months: Increasing coordination; introduction of complementary foods begins around 6 months.
    • Signs of Readiness for Solid Foods: Ability to sit with support, tongue movement side-to-side, interest in food.

  • Complementary Feeding:

    • Start around 6 months with pureed food; by 12 months, babies may move to chopped foods.
    • Gradual increase in texture and variety of food as ability to eat matures.

Nutritional Requirements During Infancy

  • Human Milk: Gold standard for nutrient provision.

  • Energy Needs: Infants require around 100 kcal/kg of body weight; significant calorie needs from fats (40-50% of total calories).

  • Macronutrients:

    • Proteins: Needs change with age (1.5 g/kg for 0-6 months, 1.2 g/kg for 7-12 months).
    • Carbohydrates: Critical for growth.
    • Lipids: Essential fatty acids required.

  • Micronutrients:

    • Vitamin D: 400 IU supplementation recommended for breastfed infants.
    • Iron: Additional iron sources needed by 6 months; iron deficiency leads to serious health issues.
    • Fluoride, Sodium, Lead Safety, Fiber, Water: Specific needs defined for optimal development.

Monitoring Feeding and Growth

  • Importance of proper feeding position to minimize risks (e.g., choking, ear infections).

  • Use of age-appropriate foods to monitor dietary requirements and growth; avoid added salt and other allergens when introducing solid foods.

  • Final Note: Parents are encouraged to respond to infants' cues for feeding readiness and preferences, creating a nurturing feeding environment.