Aims: o determine whether in-utero exposure to metformin, in offspring of women with T2DM, is beneficial or harmful in the long-term. Research Questions: 1. In offspring of women with T2DM, how does treatment with metformin during pregnancy affect a) adiposity b) growth over time c) metabolic syndrome d) cognitive and behavioral measures:2. What factors predict altered childhood adiposity and insulin resistance in these offspring? Primary Outcome: Body mass index (BMI) z-score. Secondary Outcomes: 1) other measures of adiposity (i.e. skinfolds, 2) growth over time 3) measures of insulin resistance 4) adipocytokines 5)neurodevelopment Expected Outcomes Given these increasing concerns, this study will inform the best treatment for pregnant mothers with diabetes by studying the long-term outcomes of children exposed to metformin during pregnancy.