Early nutrition and later outcomes in preterm infants.

The developmental origins of health and disease is an emerging area of interest that amalgamates many areas of scientific studies and encompasses a wide range of diverse disciplines from epidemiology to molecular biology. Evidence has accumulated to show that early life experiences, both in utero and in infancy have long-term effects on many body systems. There are now good data to show that suboptimal in utero growth, especially when combined with rapid growth acceleration in early postnatal life may increase the risk of later life metabolic disease. The mechanisms are complex but likely to involve epigenetic marks such as DNA methylation. Preterm infants frequently experience suboptimal nutrient intakes in early postnatal life and exhibit growth failure within the NICU. They also receive products that may not provide either an optimal quantity or quality of nutrients. Follow-up studies have now shown much higher risks for long-term chronic disease in children and adults who were born preterm. There are higher levels of insulin resistance and abnormal partitioning of fat deposition. The onset of puberty seems earlier, average height is less and blood pressure, measures of vascular health and lipid profiles suggest cardiovascular health is likely to differ from healthy term born controls. Despite this, there are no data to suggest an overall benefit of limiting nutrient intake, or restricting growth in preterm infants. There are strong data to show that the preterm brain is exquisitely vulnerable to undernutrition, and that suboptimal nutrient intakes may permanently affect later cognitive attainment. A clinical focus on early nutrient intakes and breast milk provision is key to optimising long-term health outcomes.