Gestational diabetes refers to the abnormality of blood sugar levels that occurs during pregnancy, at which time it is called gestational diabetes. The reason for the occurrence of gestational diabetes is due to significant changes in the body's endocrine hormones after pregnancy. The body releases many hormones, such as estrogen and progesterone, which can increase insulin resistance. Thus, a much greater amount of insulin is needed to maintain normal blood sugar levels. If the pancreatic beta cells are not sufficient to compensate for the increased insulin secretion needed to meet the normal metabolic requirements caused by these resistance factors, then elevated blood sugar and abnormal glucose metabolism occur, ultimately leading to gestational diabetes.