The environment of the fetus in the womb is emerging as a key determinant not only of its immediate status but also of the offspring's long-term well-being. This largely started with reports of striking epidemiological associations between lower, but still normal, birth weight and a marked increase in the incidence of cardiac, metabolic and neuropsychiatric disorders from childhood to senescence. In seeking to explain these observations, collectively referred to as developmental programming, ' a new subfield of biology has emerged. Major discoveries include detailing the etiological roles of...