Glycemic Profile in Women With Gestational Diabetes Treated With Glyburide

Diabetes is more likely to occur during pregnancy. When present only in pregnancy it is called gestational diabetes, and it places both mom and baby at risk for complications. Glyburide is one of the currently used treatments for diabetes during pregnancy. This drug is a medication taken by mouth that decreases sugar levels in the blood. It is known to decrease the risk of complications linked to diabetes in pregnancy. Recent studies in pregnancy have described a difference in the way and how well the drug works compared to when used outside of pregnancy. Oral blood sugar lowering agents are approved by the Food and Drug Administration (FDA) to lower blood sugar in non-pregnant subjects with diabetes. No oral (taken by mouth) blood-sugar lowering agents are FDA approved for use in pregnancy. Although Glyburide is not FDA approved for this use, it is the most commonly used oral blood sugar lowering agent in pregnancy. This research study will help us learn more about the variations in blood sugar levels in women with diabetes in pregnancy who are taking glyburide and how changes in the timing of when the glyburide is taken would affect blood glucose levels. The goals of this study are: * To find the how glucose changes throughout the day in women with diabetes in pregnancy receiving glyburide * To learn the effect of changing the time of taking glyburide on glucose levels * To learn the effect of changing the time between glyburide doses on glucose levels * To see if insulin is secreted the same throughout the day in response to a morning dose of glyburide.