The project objective is to validate a new indirect estimate of insulin status in both pregnant African-American women and Caucasian women in southern Louisiana who are at risk for gestational diabetes mellitus. There are racial differences in carbohydrate metabolism that are potentially linked to complications during pregnancy and to increased risks of obesity and diabetes in later life. The investigators will explore the use of indexes of insulin status to identify the metabolic risk profile of pregnant women which may vary by race. Understanding whether there are differences which vary by race may influence clinical screening and treatment of pregnant women.