Preterm Infant Feeding

According to research conducted in neonatal nutrition, the goal for nutrition of the preterm infant should be to achieve a postnatal growth rate approximating that of the normal foetus of the same gestational age. In Africa, unfortunately, most preterm infants, especially extremely low birth weight infants, are not fed sufficient amounts of nutrients to produce normal foetal rates of growth and, as a result, end up being growth-restricted during their post-birth hospital period. Studies have shown that growth restriction due to undernutrition, especially of protein, at critical stages of development produces long-term short stature, organ growth failure, and both neuronal deficits of number and dendritic connections as well as later behavioural and cognitive outcomes.¹

Breastmilk provides many benefits to preterm infants including:

Accelerated gut maturation
Protection against infections
Protection against sepsis
Protection against necrotizing enterocolitis
Protection against retinopathy of prematurity
Possible protective effect on neurodevelopment that are mediated by protective biomolecules and trophic factors in breastmilk.²

However, breastmilk may be nutritionally inadequate, but it can be fortified to improve its nutritional content.

New recommendations by Koletzko et al. were released in 2014 regarding the nutritional care of preterm infants^3. They recommend energy intakes of 110 – 130 kcal/kg/day and protein intakes of 3.5 – 4.5g/kg/day.³ New fortifiers have been developed with a higher protein: energy ratios (protein provided as partially hydrolysed whey), non-protein energy from lipids and carbohydrate, and higher electrolyte and vitamin levels versus control fortifiers.² When mixed with breastmilk containing 1.5 g protein/100mL (2 – 4 week milk), this new fortifier provides 3.6 g protein/100 kcal which is within the ESPGHAN-recommended and Koletzko et al. expert panel recommendations ranges for protein and energy intakes for a minimal intake volume of 140 mL/kg/day in very-low-birth-weight (infants up to 1.8 kg body weight), with osmolality below the recommended threshold of 450 mOsm/kg.² These fortifiers have been shown to be safe, well-tolerated, and to improve weight gain of preterm infants compared to control fortifier.³ Furthermore, by providing some energy as fat and replacing extensively hydrolyzed with partially hydrolyzed protein in the new breastmilk fortifier ensures a reduction in osmolality <400 mOsm/kg immediately after fortification. The protein intakes using the new fortifier are also shown to be within the ranges set out by the newest ESPGHAN and Koletzko recommendations.³

In conclusion, it is essential to develop strategies to feed preterm infants what they need to maintain normal in utero growth rates. Furthermore, this should be started at birth. By utilising new fortifiers that comply with the latest recommendations for feeding premature infants, we can ensure that preterm infants are not growth-restricted, particularly with regards to the brain and its many essential functions. This will ensure healthy growth and development.

References

Hay, W. W. Strategies for Feeding the Preterm Infant. Neonatology, 2008; 94:245–254. DOI: 10.1159/000151643
Rigo et al. Growth and Nutritional Biomarkers of Preterm Infants Fed a New Powdered Human Milk Fortifier: A Randomized Trial. JPGN, 2017; 65: e83–e93. DOI: 10.1097/MPG.0000000000001686

Koletzko, B. Poindexter, B., & Uauy, R. Nutritional Care of Preterm Infants. Scientific Basis and Practical Guidelines. World Review of Nutrition and Dietetics, 2014; 110.