Changes in glucose disposal and insulin kinetics seen in pregnancy have special importance for women with pregestational diabetes because hypoglycemia, many times of severe intensity, can occur generally in early pregnancy, a period when insulin requirements may decrease, possibly because of nausea and vomiting, compared to prepregnancy and to the second half of pregnancy; it is a dangerous condition that can leave important sequellae to the mother and the fetus[51]. The gene discussed is INS; the disease is diabetes mellitus.