The placenta develops early in gestation to nourish the fetus and allow for the exchange of nutrients, gases, and waste between the mother and fetus. It contains branching villi that increase the surface area for exchanges without mixing the maternal and fetal blood directly. The placenta's capacity and efficiency of nutrient transfer increases over gestation through developing microvilli and upregulating transporters to meet the growing demands of the fetus. Factors like placental size, blood flow, and metabolism can influence this placental transfer of materials between the mother and developing fetus.