The NNU network will form a basis for the follow-up of LBW infant cohorts to evaluate long-term effects of early nutrition and modulation of the developing gut microbiome.WHO have emphasised the importance of early life factors in the development of several important chronic respiratory diseases.

In high-income countries infants with LBW and even modest degrees of prematurity have reduced lung function in childhood and as adults, and are more likely to be diagnosed with asthma as children and chronic obstructive airways disease as adults.More recent work has demonstrated that reduced early fetal growth (eg reduced crown rump length at 10 weeks gestation) is associated with reduced lung function and increased likelihood of asthma during childhood. There is also a convincing body of evidence from HICs that reduced lung function in infancy persists through childhood, adolescence and into adult life, manifesting as wheezing illness, asthma and COPD.

These observations have focussed attention on antenatal factors that influence fetal growth, lung and immune development specifically maternal diet and micronutrient status such as vitamins A and E. There is a notable absence of observational studies of maternal diet during pregnancy in relation to newborn, childhood (and by implication adult) respiratory health in LMICs and yet nutritional interventions (preferably based on local foods) in chronically undernourished populations, ideally as a component of multifaceted interventions, may be particularly effective in establishing infants on a pathway to a lifetime of respiratory health.

Although some studies have demonstrated that at risk infants in LMIC settings have long-term difficulties with growth, nutritional status and cognitive development, the interplay between these factors is unclear. Stunting is associated with impaired child development and brain development is affected by both macro and micronutrient intake in animals. Food and micronutrient supplementation for mothers improves foetal growth and early neonatal care (appropriate resuscitation, delayed cord clamping, kangaroo mother care with early initiation of exclusive breast feeding) all support better neurodevelopmental outcomes in children whereas infections in these settings is likely to significantly impair development. However, there are few good studies which demonstrate the effect of early feeding practices in LBW newborns on longer-term outcomes in LMIC settings particularly in relation to developmental outcomes.