Managing lung diseases makes up a large part of the daily work of general practitioners, paediatricians, specialists in internal medicine, and respiratory physicians. While the spectrum of diseases managed by these different groups may differ, many of the diseases are likely to have common origins and are influenced by early life events. The fetal origins of disease have been recognised recently in the relationships between birth weight and cardiovascular disease in adults in the UK and have led to the so-called Barker hypothesis.1 This initial report has led to a growing interest in determining how early life events can influence the expression of disease later in life. This is particularly true for lung diseases with a growing recognition of the influences of the intrauterine environment on lung growth and development. The most well known example of this has been the effects of maternal smoking on lung growth.2-5 However, the influences of other environmental factors such as premature birth,6-8 maternal diet, and allergen exposure on subsequent respiratory disease are attracting increasing attention.9-12

Respiratory infections are common …