Introduction

Developmental programming of the fetus is a phenomenon that has profound implications for the health of individuals and societies. The term describes the process by which gene expression in the fetus is influenced by the intrauterine environment, such that the structure of major organs and the homoeostatic points of metabolic and endocrine systems are set for life. Through this mechanism, perturbations in the intrauterine experience that affect development may predispose to a spectrum of adult diseases, depending on the system principally affected. Thus, in a recent review the National Institute of Child Health concluded that ‘coronary heart disease, the number one cause of death among adult men and women, is more closely related to low birth weight than to known behavioural risk factors’. The list of diseases continues to grow, and now also includes diverse metabolic, neoplastic and neurological disorders. This striking effect first came to light through epidemiological studies of men in Hertfordshire, UK, who had died from cardiovascular disease. Through the records maintained by the midwives attending the births of these men it was possible to show that death rates from the disease fell across the normal range of birth weight. In a later study of blood pressure levels among men and women in Preston, UK, it was possible to relate birth weight to the weight of the placenta. People with small placentas and people with large placentas in relation to their birth weights had the highest blood pressure levels.