Medical Nutritional Therapy for Pre-gestational and Gestational Diabetes Mellitus

Pregnancy causes a multitude of metabolic changes within a woman’s body in order to provide the proper nutrients to the developing fetus. In women with diabetes type 1, type 2, and GDM （gestational diabetes mellitus） these metabolic perturbations must be treated distinctly and aggressively to optimize fetal development and health. Pre-gestational diabetes （either type 1 or type 2） has the potential to subject the developing fetus to abnormal maternal glucose levels resulting in problems with organogenesis producing congenital abnormalities or spontaneous abortion. Furthermore, gestational diabetes mellitus presents after organogenesis in the second part of pregnancy, therefore the major risk for the fetus is macrosomia. Although the goal for dietary therapy for each of these disorders is the same which is euglycaemia, the means to achieve it are very different and somewhat controversial. In the case of gestational diabetes, the main stay of therapy is medical nutritional therapy whereas in insulin requiring diabetes, dietary therapy is compensated with pre-meal insulin injections. The metabolic changes in normal pregnancy will be presented followed by the general guidelines for pregnancy. Fetal complications associated with inadequate nutrition or metabolic perturbation will be briefly explored, followed by issues and treatment for gestational diabetes mellitus, with emphasis on specific dietary therapies for GDM.