L6 Importance of Infant Feeding and Gestational Age

Importance of Infant Feeding

• Exclusive breastfeeding provides sufficient nutrition for infants to grow at a healthy rate if the mother is well-nourished.
• Human milk offers unique nutritional benefits including a high whey-to-casein ratio, essential fatty acids for brain and retinal development, and immunological/antimicrobial protection.

Gestational Age and Size

• Gestational age is assessed antenatally (last menstrual period, uterus size, fetal heart tone) and postnatally (neurologic signs, physical maturity).
• Birth weight classification includes:
  • Low birth weight (LBW) < 2500 gm
  • Very low birth weight (VLBW) < 1500 gm
  • Extremely low birth weight (ELBW) < 1000 gm
• Gestational age classifications include:
  • Premature < 37 weeks
  • Full term 37 - 42 weeks
  • Postterm > 42 weeks
• Small for gestational age (SGA) infants have a birth weight below the 10th percentile.
• Intrauterine growth retardation (IUGR) can be symmetrical (length and head growth < 10th percentile) or asymmetrical (poor weight gain but normal length and head growth).

Growth & Body Composition

• Infants double their birth weight by 4 months and triple it by 12 months.
• Growth velocity is rapid in early infancy, requiring high nutrient demand.
• In the first 4 months, 42% of weight gain is fat, decreasing to 19% in the next 18 months.

Early Feeding: Colic

• Infantile colic is characterized by excessive crying in a healthy, well-nourished infant.
• Symptoms include crying for more than 3 hours a day for at least 3 days a week for more than 3 weeks.
• Possible causes include maternal tension, smoking/alcohol consumption, allergens in breast milk or formula, and cow's milk protein.
• Colic resolves spontaneously without intervention.
• Prevalence is reported in both breastfed and formula-fed infants, and breastfeeding doesn't offer protection.

Estimating Energy Needs

• Total energy expenditure is greater in older infants than younger ones, in males than females, and in formula-fed than breastfed infants.
• Providing excess energy from complementary foods can reduce breast milk intake.

Protein

• Breastfed infants receive adequate protein for the first 6 months.
• Adequate intake (AI) for infants 0-6 months is 1.5 g/kg/day, reflecting mean intake of human milk-fed infants.
• Protein content in breast milk varies throughout lactation, but no studies show negative effects from the amount provided.
• Breastfed infants have improved immune function and fewer illnesses compared to formula-fed infants.
• Formula-fed infants may require more protein due to less efficient utilization and retention.

Lipids

• Adequate fat intake is essential for infant health, with linoleic acid crucial for growth and dermal integrity.
• Human milk contains high levels of essential fatty acids: linoleic acid, alpha-linolenic acid, arachidonic acid (ARA), and docosahexaenoic acid (DHA).
• Infant formulas are supplemented with linoleic and alpha-linolenic acid, from which ARA and DHA are derived.
• DHA is important for visual and psychomotor development, particularly in premature infants.

Carbohydrates

• 30-60% of energy intake should come from carbohydrates.
• Human milk contains 40-50% of energy as carbohydrates, primarily lactose.
• Honey and corn syrup should not be given to infants under 1 year due to the risk of botulism spores.

Water

• Infants require water for skin/lung loss and feces/urine output.
• Recommended total water intake is 0.7-0.8 L.
• Human milk and properly prepared formula provide sufficient water in typical conditions.
• Infants may need additional water in hot, humid environments, or in case of diarrhea/vomiting.
• Water deficit can lead to hypernatremic dehydration, while excess water can lead to hyponatremia.

Minerals

• Calcium: Breastfed infants retain about two-thirds of their calcium intake, with an AI of 200-260 mg/day for 0-6 months.
• Fluoride: Essential for preventing dental caries, but excessive intake can cause fluorosis.
  • Human milk is low in fluoride, with commercially prepared infant cereals and fluoridated water being significant sources.
• Iron: Full-term infants have adequate iron stores for the first 4 months.
  • Iron-fortified cereals and infant formula are good sources; cow's milk is not a good source and should be avoided before 12 months.
  • Monitoring iron status is important due to the long-term effects of iron deficiency anemia.

Vitamins

• Vitamin B12: Milk from mothers who restrict their B12 intake is deficient.
• Vitamin D: Breast milk provides most vitamins but is deficient in vitamin D.

Explore the critical aspects of infant feeding, emphasizing the benefits of exclusive breastfeeding and its nutritional advantages. Additionally, understand the classifications of gestational age and birth weight, including the implications of low birth weight and intrauterine growth retardation.