If a pregnant woman has elevated blood glucose, it can have some harmful effects on the development of the fetus, and the specific harm is manifested in several aspects. In the early stage of pregnancy, if elevated blood sugar occurs, it can affect the normal development of the embryo and can cause fetal growth arrest or miscarriage, and may also cause fetal developmental malformations, mainly causing abnormalities in the development of the nervous system and heart. Elevated blood glucose in the middle of pregnancy can cause an increase in blood viscosity, which can lead to vasoconstriction and thus increase the risk of gestational hypertension, which poses a great risk to pregnancy and may lead to termination of pregnancy. Increased blood glucose in pregnant women is conducive to the growth of pathogenic bacteria and increases the risk of infection, which can lead to candidiasis and premature rupture of membranes, and may increase the risk of miscarriage or preterm delivery. If the blood sugar is high for a long time, it may cause the fetus to grow excessively and appear as a giant fetus, or there may be too much amniotic fluid, which will increase the burden on the organs of the pregnant woman, thus increasing the risk of some complications during pregnancy and making it easier for fetal distress to occur. Elevated blood glucose during pregnancy can be harmful, so it is important to have timely maternity checkups, and if elevated blood glucose is found, it must be strictly controlled under the guidance of a doctor to avoid complications. If necessary, insulin treatment.