Fetal origins of adult disease—the hypothesis revisited

The idea that stimuli or insults during critical or sensitive periods in early life can have lifetime consequences is well established in developmental biology and has been termed “programming.”1 The first evidence for programming, obtained over 100 years ago, confirmed the critical period for imprinting in birds.2 Programming stimuli may be generated endogenously (for instance, internal hormonal signals3) or they may be environmental. One important type of environmental programming is that induced by early nutrition. Since McCance's studies in the 1960s on the long term effects of early nutrition in rats,4 numerous animal studies have shown that nutrition in infancy or fetal life can induce lifetime effects on metabolism, growth, and neurodevelopment and on major disease processes such as hypertension, diabetes, atherosclerosis, and obesity.5^–8 If these phenomena applied in humans, it would be a matter of major public health and clinical importance.