Fetal growth restriction in animal models

In addition to genetic components, fetal growth is predominantly determined by uterine perfusion and the resulting supply of nutrients and oxygen. If there is a chronic reduction in uterine blood supply or if the natural incr ease in uterine perfusion during the course of pregnancy does not take plac e, growth is hindered and the fetus is put at risk. Among the great number of experimental models of intrauterine growth restri ction, those involving a generalised reduction in the uteroplacental blood supply are of significance to questions relating to human pregnancy, Despit e physiological differences, particularly with regard to maternal metabolis m and placentation, the occlusion model in the pregnant sheep is suitable f or investigating questions about fetal and placental growth, nutrient trans fer and the fetal oxygen economy.