Infant Nutrition: Breastfeeding vs. Formula Feeding and Premature Infant Feeding
Breast milk is the optimal nutrition for all infants, including premature babies, and should be the first choice whenever possible, with exclusive breastfeeding recommended for approximately the first 6 months of life. 1, 2
Breastfeeding vs. Formula Feeding in Term Infants
Breastfeeding Advantages
Breast milk provides superior nutritional and immunological benefits that formula cannot replicate. 1, 3
Breast milk contains beneficial commensal bacteria that enhance infant health by preventing pathogen adhesion and promoting gut colonization, reducing gastrointestinal disease and mortality rates compared to formula-fed infants. 3
Breastfeeding is associated with improved immune development and lower rates of infections. 3
Breast milk has significantly lower levels of advanced glycation end products (AGEs) compared to infant formula—up to 670-fold lower—which may reduce the risk of non-communicable degenerative diseases in adulthood. 4
The energy content of human milk averages 0.62 kcal/g (2.6 kJ/g), providing complete nutrition for the growing infant. 2
Formula Feeding When Breastfeeding Is Not Possible
When breast milk is unavailable, standard iron-fortified cow's milk-based formula is the evidence-based alternative for healthy term infants. 1
Iron-fortified formula must be used to prevent iron deficiency anemia, which is common when non-fortified options are used. 1
Soy-based formulas are not recommended for prevention of allergic disease or colic due to insufficient evidence of benefit. 1
Hydrolyzed formulas are not recommended for prevention of food allergies in healthy infants due to lack of evidence. 1
Whole cow's milk should not be introduced before 12 months of age, as early introduction leads to iron deficiency anemia and increases the risk of cow's milk protein allergy. 1
Critical Feeding Guidelines for Term Infants
Newborns should feed on demand, at least 8-10 times in 24 hours (approximately every 2-3 hours). 2
Day 1 newborns have a breastmilk intake of approximately less than 100 mL total for the first day, with feeding occurring 8-12 times per 24 hours. 2
Breastmilk intake increases rapidly to 500-600 mL per day by days 4-5, reaches 600-800 mL per day after 1 month, and 700-900 mL per day after 6 months. 2
Frequent feeding (8-10 times/day) decreases newborn weight loss, reduces the need for supplements, and lowers the risk of clinically significant hyperbilirubinemia. 2
Breastfeeding 9-10 times per day is associated with lower bilirubin concentrations, while breastfeeding fewer than 7 times per day is associated with higher bilirubin concentrations. 2
Important Supplementation Requirements
Vitamin D supplementation (400 IU daily) is required for all breastfed infants and those consuming less than 28 ounces of formula per day. 1
Feeding Premature Infants
Hierarchy of Feeding Options for Premature Babies
For premature infants, the feeding hierarchy is: (1) mother's own milk, (2) donor human milk, (3) preterm formula. 5, 6, 7
Mother's Own Milk for Premature Infants
Mother's expressed milk provides short and long-term health benefits for very low birth weight infants (<1500g), including reduction of necrotizing enterocolitis, late-onset sepsis, and improved neurodevelopment. 2, 5, 7
Exclusive breastfeeding remains the optimal option for premature infants whenever possible. 5
When supplementation is necessary, expressed maternal milk is preferred over formula. 2
Continuous support of breastfeeding and adequate education regarding feeding preterm infants should be provided. 5
Donor Human Milk as Second Choice
When mother's own milk is insufficient or unavailable, donor human milk is the preferred alternative before considering preterm formula. 5, 6, 7
Feeding with donor milk as a sole diet or supplemental to maternal milk confers immunological advantages and significantly lower rates of necrotizing enterocolitis compared to preterm formula feeding. 5, 7
Donor human milk reduces the incidence of morbidities such as necrotizing enterocolitis and sepsis compared to formula milk. 7
Preterm Formula: When and How to Use
Preterm formulas are indicated for enteral feeding of preterm very low birth weight infants only when sufficient maternal breast milk and donor human milk are not available. 6
When breast milk is insufficient or unavailable, formula milk is a nutritionally acceptable option due to its higher caloric density and protein content. 7
Preterm formula results in greater growth velocity compared to donor milk alone, but this growth advantage comes with increased risks. 5, 6
Critical Risks of Preterm Formula
Preterm formulas carry increased risks of necrotizing enterocolitis, possibly from cow milk antigen or different gut microbiomes, increased duration of total parenteral nutrition, and increased rates of sepsis. 6
While preterm formulas improve neurodevelopmental outcomes compared to term formulas and unfortified donor milk, they do not produce neurodevelopmental outcomes better than fortified human milk. 6
Hospital handling of fortifiers and formula milk is associated with increased risk of sepsis in premature infants. 7
Fortification Strategy for Premature Infants
Breastfeeding is often nutritionally insufficient for premature infants, requiring the addition of fortifiers to ensure necessary nutrients and calories. 7
- The preterm infant's diet should incorporate breast milk whenever possible to reduce the incidence of morbidities, even when fortification or supplementation with formula is necessary. 7
Special Considerations for Premature Infant Feeding
For infants with intestinal failure, breast milk remains the first choice even in severe illness; if unavailable, elemental formula should be started in early infancy and severe illness, then switched to extensively hydrolyzed, then polymeric feeds as tolerated. 1
Growth parameters (weight, length) should be monitored regularly in all infants, especially those on specialized formulas. 1
Breastfeeding the premature infant is both possible and desirable, with premature infants deriving benefits from breast milk that they cannot receive from formula, particularly regarding brain growth and development and disease protection. 8
Common Pitfalls to Avoid
Do not switch formulas frequently based on normal infant fussiness or minor spit-up, and do not use hydrolyzed or soy formulas as a preventive measure without medical indication. 1
Avoid breast milk supplements unless breastfeeding technique and frequency have been optimized first or when supplementation is medically necessary. 2
Phototherapy for jaundice is not an indication for formula supplementation unless bilirubin concentrations are approaching exchange transfusion levels. 2