Personal behaviors can influence development of Gestational Diabetes Mellitus (GDM), a condition that can adversely affect the pregnant woman, her developing fetus and future events for both. To reduce GDM risk, we will develop and implement an in-person team and web-based nutrition and exercise program for women, beginning in their first trimester. A scripted, peer-led, 20-week educational program, tailored for pregnant women working in teams (5 women/team), will be developed and implemented among pregnant employees and/or their spouses. Each weekly thirty minute session will focus on achieving 30-minutes of moderate daily physical activity with nutrition targets of five servings of fruits and vegetables, 3 servings of whole grains and lower fat food choices. Diet, exercise and lab assessments will occur before enrollment during the first trimester, each subsequent trimester and 12 weeks after delivery. In addition to exercise and diet survey results, we will assess fasting glucose, insulin, hemoglobin A1C levels, pregnancy weight gain, blood pressure, lipid and lipoprotein levels, pedometer records, weekly accelerometer data, each trimester and at 12 weeks post delivery, as well as gestational birth age, Apgar score, delivery mode and infant birth weight, and weekly health thermometer self-ratings during the assessment period.