Gestational diabetes is one of the common diseases that affect fetal development. As the quality of life improves, the incidence of gestational diabetes is gradually increasing. The hyperglycemic state of a pregnant woman during pregnancy can have a significant impact on the fetus and the pregnant woman herself. The impact of diabetes varies with the stage of pregnancy. In the early stages of pregnancy, hyperglycemia can cause abnormal embryonic development and even miscarriage in severe cases. As the pregnancy progresses, the fetus gradually develops, and under the effect of maternal hyperglycemia, the fetus gains weight too quickly, which can easily form a huge baby. The development of various tissues and organs of the fetus is slower than normal fetus, and at the same time, it can be combined with increased amniotic fluid. In late pregnancy, due to the abnormal development of the fetus, neonatal whistling distress syndrome may occur after birth, affecting the life and health of the newborn. In addition, the metabolism of pregnant women changes during pregnancy, and pregnant women with gestational diabetes are prone to diabetic ketoacidosis, which can endanger their lives in serious cases. In summary, gestational diabetes has a great impact on both the pregnant woman and the fetus, so it is recommended that patients should always pay attention to monitoring changes in blood sugar and seek timely medical treatment in order to avoid some of the dangers.