Preterm birth occurs in 25% of women with insulin requiring diabetes in pregnancy. The administration of corticosteroid therapy to accelerate fetal lung maturation is indicated in women at risk for preterm birth. Although corticosteroid therapy significantly decreases the risk for respiratory distress syndrome in the newborn, such therapy can lead to transient elevations in maternal glucose levels, potentially resulting in life-threatening maternal metabolic abnormalities, low oxygen levels in the fetus, and in extreme cases, stillbirth. Because the elevations in glucose levels may drastically increase over a short period of time, intense monitoring of maternal glucose levels to achieve strict glycemic control and treatment is preferred with the use of insulin. The purpose of this study is to compare the timing, duration and severity of maternal hyperglycemia after corticosteroid administration in women with insulin-requiring diabetes compared to those without diabetes in pregnancy.