ABSTRACT
Major changes take place in the intermediary metabolism throughout pregnancy: changes that will facilitate the fetal needs of energy and precursors for fetal and placental growth, as well as for placental hormone synthesis. Because the insulin resistance that takes place in second half of pregnancy plays a key role in development of gestational diabetes mellitus (GDM), any condition susceptible to exacerbating this resistance may play a role in the development of GDM. Independent of the mechanisms involved, in GDM, there is a relative lack of insulin during a period of time with high insulin needs to compensate the insulin resistance that develops in third trimester of pregnancy. In GDM, as occurs in other conditions of insulin resistance and beta-cell dysfunction, there is an increase in plasma levels of triglycerides and cholesterol. In GDM, there is an increase in the number of essential and nonessential amino acids in umbilical venous and arterial concentration, compared to the values found in normal pregnancies.
