Gestational diabetes is a type of diabetes that develops only during pregnancy. Diabetes means your blood glucose, also called blood sugar, is too high. Your body uses glucose for energy. Too much glucose in your blood is not good for you or your baby. Gestational diabetes is usually diagnosed during late pregnancy. If you are diagnosed with diabetes earlier in your pregnancy, you may have had diabetes before you became pregnant. Treating gestational diabetes can help both you and your baby stay healthy. You can protect your baby and yourself by taking action right away to control your blood glucose levels.