Metabolic interrelationships of placenta and fetus

Placental-fetal metabolic relationships are complex and dynamic. For example, the placenta consumes glucose as well as transports it to the fetus, thus regulating fetal glucose supply and fetal plasma glucose concentration. In turn, fetal plasma glucose concentration, which is also regulated by the relative rates of fetal glucose utilization and production (both also regulated by glucose-induced insulin secretion), regulates placental glucose consumption and the partition of uterine glucose uptake into placental glucose consumption and glucose transfer to the fetus. For amino acids, unique placental transport and metabolic processes determine the quality as well as the quantity of amino acids that enter the fetal circulation. In turn, this unique qualitative and quantitative supply of amino acids provides a variety of regulatory controls over a diverse set of developmental metabolic processes as well as fetal protein turnover and growth. Similarly, complex placental lipid metabolism and transport affect the quality and quantity of lipids delivered to the fetus and thus the composition and amount of lipids in fetal tissues. Clearly, placental and fetal metabolic interrelationships represent vital and unique processes that control and determine many aspects of fetal development.