Ten years ago studies in Britain showed for the first time that people who had low birth weight were at increased risk of coronary heart disease and the disorders related to it: stroke, non-insulin dependent diabetes, raised blood pressure, and the metabolic syndrome.1-3 In a study of 16 000 men and women born in Hertfordshire death rates from coronary heart disease fell twofold between those at the lower and upper ends of the birth weight distribution. In groups investigated clinically the prevalence of non-insulin dependent diabetes and impaired glucose tolerance fell threefold. Such findings led to the “fetal origins hypothesis”, which states that cardiovascular disease and non-insulin dependent diabetes originate through adaptations that the fetus makes when it is undernourished.4 These adaptations, which include slowing of growth, permanently change the structure and function of the body.

Recently, associations between low birth weight and later disease have been widely replicated in studies in Europe and the USA.5-7 These studies have also confirmed that the associations are not the result of confounding variables, such as low socioeconomic status and smoking, which act in postnatal life. Influences that act in postnatal life do, however, add to the effects of low birth weight. For example, the highest prevalence of non-insulin dependent diabetes is found in people who had low birth weight but were obese as adults.2 Replication of the associations between low birth weight and later disease in large studies such as the American nurses’ study has been possible because most adults are able to discover their birth weights from parents or …