Nourishing preterm infants: Key nutritional needs for growth and development

Preterm infants face specific nutritional challenges, the preterm infant’s nutritional milieu has an important impact on subsequent health especially on the developing brain and on cardiovascular function and metabolism.Breast Milk.Current science Favorsbreastfeeding. Infancy isa crucial time for the development of a healthy intestinal microbiome, and this is especially true for preterm infants,who’s gastrointestinal (GI) tracts are immature at birth.Fresh human milk is a source of starter microbiome, pathogen-specific immunoglobulin (Ig), macrophages, andother immune cells as well as antimicrobial proteins including lysozyme, lactoferrin, and cytokines. Every infant’s GI microbiome is different.There are likely epigenetic processes through which early nutrition and development of the gut microbiome influence long-term health.Human milk oligosaccharides (HMO): Present only in human milk, HMOsare nondigestible sugars/ glycans uniquely found in human milk HMOs have a prebiotic effect supporting the growth of commensal (or beneficial) bacteria and have antiadhesive properties, protecting against infection, modulate the immune response of the infant, reducing proinflammatory cytokines, promoting anti-inflammatory cytokines, promoting maturation of gut epithelial cells, and possibly lowering the risk for NEC. In addition, HMOs are a source of sialic acid, an important nutrient for brain developmentFatty acids: The fatty acids found in human milk are also uniquely suited to support infant growth and development. These include arachidonic acid (ARA) and docosahexaenoic acid (DHA) as well as the essential fatty acids linoleic acid (LA)and a-linolenic acid (a-LA), which are precursors of ARA and DHA, respectively. ARA supports growth, brain development, immunity, and the immune response.DHA: is particularly important for brain development, as it supports growth of the myelin sheath, brain cell membranes, and retinal photoreceptors. (27)(28) LA/a-LA support maturation of multiple organ systems, growth, and regulationMFG: The milk fat globule (MFG) found in human milk is a source of ready energy, influences lipid metabolism and absorption rates, and contains both DHA and ARA. The MFG membrane supports maturation of the GI tract and modulates the gut microbiota. It also has antimicrobial, anti-inflammatory, and prebiotic functions, and supports cognitive development.IMPORTANCE OF FORTIFIERS FOR PRETERM INFANTS FED HUMAN MILKTo meet the high nutritional demands of VLBW infants, a fortifier must be added to human milk. Fortifiers are typically composed of a concentrated form of carbohydrates, lipids, and proteins, allowing preterm infants to obtain as much nutrition as possible in typical feeding volumes. The development of human milk fortifiers that were themselves made from human milk has made it possible to feed exclusive human milk diet (EHMD). Research suggests that the benefits of an EHMD in VLBW infants may extend beyond the first weeks and months of age, potentially resulting in better cardiac, neurodevelopmental, and metabolic outcomes into adulthood. EHMD is adopted as standard of care in most Neonatal intensive care units.What to feed preterm infants when the mother’s own milk is in short supply or not available?Alternatives include preterm formula or donor breast milk. WHO, preterm VLBW infants who cannot be fed mother's own milk should be fed donor human milk. This recommendation is relevant for settings where safe and affordable milk-banking facilities are available or can be set up. This recommendation does not address sick LBW infants or infants with birth weight less than 1.0 kg.Preterm Formula. Several historical interventional studies established the benefits to growth and neurodevelopment that are achieved by providing hospitalized preterm infants withthe high-nutrient preterm formula.These infants had higher verbal IQ scores and larger caudate size, beneficial effects of nutritional fortification that had persisted throughout childhood and into adolescence. Early research demonstrated how use of human milk–based nutrition in this patient population can reduce ratesof sepsis and NEC.These findings and others have led to policy statement recommending that all preterm infants should receive human milk in both developed and developing countriesParenteral NutritionThe macronutrient intakes recommended to match foetal growth most closely are parenteral delivery of 85 to 111 kcal/kg of energy per day and 3 to 3.5 g/kg of proteinper day and enteral delivery of 110 to 130 kcal/kg of energy per day and 3.5 to 4.5 g/kg of protein per day.preterm infants who received more protein and energy in the first week after birth (98% in parenteral form) gained more weight and had better neurodevelopmental outcomes at 18 months of age. protein administration reported an improved positive nitrogen balance. Which are the critical periods for effects of nutrition on neurodevelopment and cardiometabolic health in preterm infants?In preterm infant, the period of time from birth until term-equivalent age aligns developmentally with the thirdtrimester of gestation for a foetus, with brain development involving processes such as cortical folding and gyrification, axonal development, and neuronal proliferation and migration, which is the most critical periods .As the developing brain appears to be highly sensitive to nutrition from preterm birth to term-equivalent age, targeted improvements in nutritional care during this period are likely to benefit neurodevelopmental outcomeIn terms of the cardiovascular system and metabolism of preterm, An observational study found that greater weight gain from birth to 2 weeks of age, was associated with insulin resistance in adolescence Conversely, overnutrition and excess weight gain after reaching term equivalent age predicts later obesity and higher blood pressure in both animal models and human infants.Post discharge Preterm nutritionMicronutrients such as calcium, phosphorus, iron, zinc, and vitamins A, D, and E are required to be supplemented for the initial 12 months of age.Human milk does not deliver sufficient vitamin D.80%Foetal accretion of calcium and phosphorus occurs in the third trimester, preterm infants are at risk for osteopenia or metabolic bone disease. Hence Vitamin D 400 IU/day is recommended for preterm infant after hospital discharge.Nutrition is a cornerstone of care for preterm infants, influencing their survival and long-term development. Providing calories, macronutrients, and micronutrients through carefully balanced parenteral and enteral nutrition can optimize growth and neurodevelopment while minimizing complications.Authored by: Dr. Prashanth S Urs, Senior Consultant Neonatologist- Apollo Hospitals BG Road & Seshadripuram, Bangalore