Prenatal “glucose screening” is a laboratory test to screen mothers for early detection of diabetes during pregnancy. Gestational diabetes mellitus, which includes the combination of pre-existing diabetes mellitus (also known as diabetes mellitus combined with pregnancy) and gestational diabetes mellitus (GDM), refers to the first occurrence or detection of diabetes mellitus during pregnancy, and includes some patients who had diabetes mellitus before pregnancy but were diagnosed for the first time during pregnancy, and was classified as a separate type of diabetes mellitus by the WHO in 1979. Due to the endocrine changes during pregnancy caused by the disruption of the body’s glucose metabolism, it mainly occurs in the middle and late pregnancy, peaking at 32-34 weeks of pregnancy. Therefore, the routine screening for gestational diabetes is scheduled at 24-28 weeks of gestation. The most widely used clinical screening method for gestational diabetes is the glucose stress test (GCT), referred to as “glucose screening”. Pregnant women with a GCT of 7.8-11.1 mmol/L require further glucose tolerance testing to confirm the diagnosis of GDM. For those who have high risk factors for diabetes such as excessive drinking, excessive eating, and excessive urination, and those who have repeatedly positive urine glucose in early pregnancy, GCT should be performed during the first pregnancy checkup.