The nutrient composition of the human diet varies enormously among populations yet the healthy human newborn is essentially the same the world over. The available evidence points to extensive homeostatic mechanisms at work within the placenta to ameliorate some of the variation in the quality of the maternal diet by regulating the mix of nutrients to the developing fetus. However, these mechanisms can only operate on the nutrients already available in the maternal circulation. The maternal diet and maternal circulating concentrations of many nutrients are major determinants of the concentrations in the fetal circulation and the fetus clearly has the ability to cope with relatively large variations in nutrient availability in the cord blood. The fetus also plays an active role in regulating placental nutrient transfer. The rate of placental nutrient transport is directly influenced by the trans-placental concentration gradient, which is in turn largely determined by the rate of uptake by the fetal tissues. Another major determinant of placental nutrient transfer is the umbilical blood flow, which is approximately linearly related to the fetal weight, and hence the fetal nutrient requirement, throughout gestation. Finally, the most intimate connection between the fetus and the placenta is the way in which different parts of metabolic pathways and cycles are distributed between the placenta and fetal tissues, mainly the fetal liver. Thus, whilst the placenta has to provide the correct mix of nutrients in sufficient quantities to support fetal growth and development throughout pregnancy it is the fetus itself that ultimately regulates many key aspects of placental nutrient transfer function.
Was this article helpful?
Trying To Lose Weight Can Be Tough. But... Not Losing Weight and Gaining What You Lost Back, Sucks. If you've ever felt that no matter what you do to lose weight nothing seems to work. If you've ever felt that there has got to be some kind of a system or way to lose weight...but just have not found it yet.