Maternal Lipid Metabolism and Its Implications for Fetal Growth

During gestation, the mother has to adapt her own metabolism to support a continuous extraction of nutrients through the placenta to sustain fetal development. Quantitatively, glucose and amino acids are the most abundant of these nutrients crossing the placenta (1,2), and the continuous dependence of the fetus on these compounds is well-known. However, the placenta is practically impermeable to lipids, except for free fatty acids (FFA) and ketone bodies (3). Nevertheless, the marked changes in the maternal lipid metabolism during gestation do have important implications for fetal growth. Two consistent manifestations of altered maternal lipid metabolism occurring during gestation are the accumulation of lipids in maternal tissues (4,5) and the development of maternal hyperlipidemia (6,7). It is known that conditions that restrain or alter any of these manifestations—such as hypothyroidism or overt diabetes during the first half of gestation—will greatly affect fetal growth at late gestation, even if they are compensated for by appropriate hormonal treatment during the second half of gestation (8,9). In this chapter, we analyze the changes that occur in maternal lipid metabolism during gestation and how they contribute to fetal development.