The effects of high blood sugar in pregnancy on the pregnant woman are miscarriage, gestational hypertension, diabetic ketosis, and excess amniotic fluid. The effects on the fetus are macrosomia, intrauterine distress, neonatal hypoglycemia and so on. 1. The danger of high blood sugar to pregnant women: ① prone to spontaneous abortion, placental abruption, preterm labor and so on. ② easily combined with gestational hypertension and other diseases. Diabetic ketoacidosis or urinary tract infections are likely to occur. ③Prone to diabetic ketoacidosis or urinary tract infection. ④Prone to excessive amniotic fluid. 2. The danger of high blood glucose to the fetus: ① may lead to larger than the gestational age of the child, or smaller than the gestational age of the child. ② Increase the chance of intrauterine distress of the fetus. ③May increase the risk of fetal birth injury. ④ The fetus is in a state of hyperglycemia, and when the baby is born, disconnecting the umbilical cord can easily lead to neonatal hypoglycemia, which can easily lead to neonatal injuries if not corrected in time. Hyperglycemia in pregnancy must be under the guidance of the doctor to actively control blood sugar, not blindly self-medication to avoid adverse effects.