Gestational diabetes is a condition that develops during pregnancy and causes a patient's blood glucose levels to be too high. During pregnancy, there may be insufficient insulin production or resistance to insulin (the hormone that usually helps us to use glucose for energy); when this happens, the glucose is not used as well, it stays in the blood, and causes high blood glucose levels. Gestational diabetes resolves soon after delivery, but it does cause an increased risk for future development of diabetes. If it does not resolve after delivery, it may be a sign that there had been unknown pregestational diabetes present before pregnancy. Risk factors for gestational diabetes include obesity, physical inactivity, history of gestational diabetes in a previous pregnancy, history of a very large baby in a previous pregnancy, hypertension, heart disease, polystic ovary syndrome, and family history of diabetes. Gestational diabetes can cause other difficulties during pregnancy such as a very large fetus, labor difficulties such as shoulder dystocia, need for cesarean delivery, heavy bleeding after delivery, jaundice and/or low blood sugar in the newborn, need for neonatal ICU admission, and even risk of stillbirth.