Treating Prediabetes in the First Trimester

The investigators plan to study a sample of women with prediabetes (diagnosed by Hemoglobin A1c (HbA1c) 5.7-6.4% or fasting plasma glucose (FPG) 92-125 mg/dL) in the first trimester of pregnancy, and patients will be randomized to first trimester or third trimester treatment; the first trimester group will receive intervention immediately upon diagnosis of prediabetes whereas the third trimester group will receive only routine prenatal care until 28 weeks at which time they will receive intervention. Intervention is defined as: * diabetes education * blood glucose monitoring * medications as needed * growth ultrasounds * antenatal testing The primary outcome is umbilical cord C-Peptide \>90th percentile. Secondary outcomes include neonatal fat mass at delivery, infant weight-for-length at 12 months of age, maternal gestational weight gain, and biomarkers (chemicals) measured in the placenta and the baby's umbilical cord blood. The investigators hypothesize that women who undergo the above intervention in the first trimester will deliver significantly fewer neonates with umbilical cord C-Peptide \>90th percentile, and that the neonates will have lower fat mass, and weight-for-length at 12 months. The investigators further hypothesize that a greater proportion of patients undergoing first trimester intervention will have appropriate maternal gestational weight gain as defined by the Institute of Medicine, and a greater proportion will return to prepregnancy weight within 12 months.