Prenatal undernutrition, glucocorticoids and the programming of adult hypertension

1. A range of epidemiological studies has shown that poor intra-uterine growth is associated with an increased prevalence of cardiovascular disease, non-insulin-dependent diabetes mellitus and the Metabolic syndrome in adult life. 2. Because these associations are independent of adult lifestyle or current size, it has been postulated that a reduced intra- uterine nutrient supply perturbs fetal growth and, concomitantly, alters or programmes the structure and function of developing systems. 3. A reduced fetal nutrient supply may be a consequence of poor placental function or inadequate maternal nutrient intake. 4. It has been proposed that one outcome of either a suboptimal placental or maternal nutrient supply is exposure of the fetus to excess glucocorticoids, which act to restrict fetal growth and to programme permanent changes in the cardiovascular, endocrine and metabolic systems. 5. While a range of studies in the rat has investigated the impact of maternal undernutrition on arterial blood pressure in the offspring, there have been relatively few studies in species, such as the sheep, in which the responses of the cardiovascular and neuroendocrine systems to intra-uterine undernutrition can be measured before birth. 6. The present review summarizes recent evidence that poor placental function or inadequate maternal nutrition each results in an increased exposure of fetal sheep tissues to glucocorticoids and, in specific, changes in the regulation of fetal arterial blood pressure. 7. These studies are important in determining how the timing, type and duration of fetal nutrient restriction are each important in determining the nature of the fetal neuroendocrine and cardiovascular adaptive responses and their pathophysiological sequelae in later life.