Southampton researchers identify significant link between susceptibility to respiratory disease and weight gain in early infancy

A study by researchers from the University of Southampton and the Medical Research Council (MRC) has shown that lower rates of growth in the womb and higher weight gain in the first weeks after birth could predispose individuals to chest illnesses in later life.

The research suggests that improving a baby's lung growth and development before and after birth could have lifelong benefits for its respiratory health.

The collaborative study, by a team from the University's Allergy and Inflammation Sciences Division and the MRC Environmental Epidemiology Unit at Southampton, found that lower rates of growth in the womb and higher rates of weight gain in early infancy are associated with impaired lung development.

The research is published today in the American Journal of Respiratory and Critical Care Medicine.

The study team measured various lung function parameters in 131 healthy babies aged from five to fourteen weeks, some with a birthweight below the norm. They also recorded the speed with which the babies gained weight. Significantly it was both a lower birthweight and a greater weight gain in the early weeks after birth that were associated with reduced respiratory capacities. The mothers of the babies taking part were all taking part in the ground-breaking Southampton Women's Survey, a project studying the link between a mother's health and nutrition before and during pregnancy and the growth and development of their children.

Dr Jane Lucas of the University of Southampton's School of Medicine, who led the study, commented: "This is the first time that a link has been identified between greater weight gain in the weeks following birth and impaired lung development.

"It is unlikely that different types of feeding could be responsible for this effect. Somewhat surprisingly, the findings did not appear to reflect either whether the baby was breast or bottle-fed, or the known harmful effects of smoking during and after pregnancy. We are more inclined to think that the post-natal weight gain of some babies could represent a catching-up process, a consequence of growth restriction in the later months of pregnancy. That would mean that the foetus' lungs had not reached their normal dimension, which would contribute to reduced lung function."

Professor John Warner from the University's School of Medicine said, "This has been a unique collaboration between two divisions in the Medical School, bringing together very detailed measurements of growth and lung function in young infants.

"While the relationship of low birth weight and reduced lung function has been recognised for many years, this is the first work to recognise the relationship between rapid infant weight gain and poor lung function. We believe the reduced lung function in these infants may have implications for susceptibility to later respiratory disease, in particular asthma."

The research is supported by the charities SPARKS (Sport Aiding medical Research for KidS), The British Lung Foundation, and Hope; and by the Medical Research Council.