During pregnancy, there are two scenarios concerning diabetes: one is where diabetes is diagnosed before pregnancy, referred to as pregestational diabetes combined with pregnancy. The other scenario is where the sugar metabolism is normal before pregnancy, or there is an underlying reduced glucose tolerance, and diabetes appears or is diagnosed during pregnancy, also known as gestational diabetes. Over 80% of diabetic pregnant women have gestational diabetes. Typically, gestational diabetes doesn't show clear symptoms of the classic "three polys and one less" - excessive drinking, eating, urination, and weight loss. Some women with gestational diabetes may experience itching of the vulva, caused by repeated infections with Candida albicans. Additionally, gestational diabetes may lead to conditions like fetal macrosomia and polyhydramnios during pregnancy, and pregnant women with gestational diabetes are more prone to infections.