Clinical factors that affect AFP levels during pregnancy are: · Maternal weight - AFP concentration decreases with increase in maternal weight · Race - African American women have 10-15% higher AFP levels as compared with Caucasian women · Insulin Dependent Diabetes Mellitus (IDDM)-AFP levels are approximately 20% lower in women with IDDM as compared to general population · Multiple gestation - AFP level is directly proportional to the number of fetuses.