ABSTRACT
Fetuses of diabetic mothers have markedly different growth rates and develop considerably different body compositions despite all having a mother with diabetes mellitus during her pregnancy. To appreciate how such disparate patterns of growth can occur, it is important to understand the basic aspects of nutrient transport to the fetus. Data from a variety of animal models, principally sheep, are used to augment and support the more limited information from humans. The principal metabolic nutrients in the fetus are glucose and amino acids. Glucose serves as the principal substrate in the fetus for maintenance energy production and expenditure, energy storage in glycogen and adipose tissue, and the energy requirements of protein synthesis and growth. The placenta plays a key role in nutrient transfer to the fetus. The placenta contains membrane transporter proteins for glucose, lactate, and fatty acids that facilitate their transport to the fetus by concentration gradients.
