Cardiovascular diseases are the leading causes of morbidity and mortality in the United States. On the basis of an interplay of genetic and environmental factors, these diseases appear to be rooted in childhood. Recent reports implicate the intrauterine nutritional environment regulating fetal growth as a determinant of adult cardiovascular disease. According to this concept, impaired fetal growth, with consequent lower birth weight, results in alteration in organ structure and subsequent functional impairment in later life. Higher blood pressure (BP) has been suggested as the possible link between compromised intrauterine growth and the long-term risk for cardiovascular disease. Despite the many reports which appear to support the low birth weight - high BP hypothesis, this concept is in conflict with the body of data on the association of BP with body size in childhood, adolescence, and adulthood which consistently demonstrates a direct relationship between body weight and BP.