Maternal nutrition is vital to placental and fetal development during gestation. Fetal development represents a critical period in humans. Growth of a normal fetus is controlled by balance of genetic, maternal, placental and fetal factors. Arginine plays a decisive role in nutrition and metabolism. It is a common substrate for nitric oxide (NO). It is an endothelium-derived relaxing factor. NO is essential to the regulation of placental–fetal blood flow. Arginine plays a crucial role in reproduction, fetal development, wound healing, maintenance of tissue integrity, and immune function, as well as treatment of diseases in pregnancy. The arginine serves as a precursor for molecules that regulate embryonic survival, fetal growth and pregnancy maintenance. Intravenous or oral administration of arginine may provide a potentially novel solution to enhancing placental-fetal blood flows (and therefore transfer of nutrients and O2 from mother to fetus), thereby improving fetal growth. Promoting an optimal intrauterine environment will not only ensure optimal fetal development, but will also reduce the risk of chronic diseases in adults.