The effects of diabetes on pregnant women and fetuses are closely related to the type of diabetes, the degree of the disease, the time of appearance of elevated blood sugar and the level of blood sugar control during pregnancy. (a) The effects of diabetes on pregnant women: 1. The fertility of diabetes is reduced, with menstrual irregularities of 70% and a conception rate of 30% after treatment. 2, the incidence of spontaneous abortion, preterm delivery and stillbirth is higher than the normal pregnancy group, with a miscarriage rate of 15%. 3. The incidence of hyperemesis (PIH) is 20%. The incidence of PIH increases significantly in those with long duration of diabetes, microangiopathy and poor glycemic control during pregnancy, and the incidence of PIH is as high as 54% when diabetes is combined with nephropathy: once diabetes is combined with PIH, the prognosis for perinatal infants is poor. Causes of hypertension: 1) the increase of sugar reabsorption accompanied by sodium ion absorption during hyperglycemia, which increases the sodium volume and extracellular fluid volume in the body and increases blood pressure; 2) intracellular glucose can increase the reactivity of vascular smooth muscle to sympathetic nervous system during hyperglycemia, which increases blood pressure; 3) blood glucose is similar to electrolytes, which can enter the wall of small arteries and cause water retention and enhance vascular reactivity, resulting in increased peripheral vascular resistance, 4) glucose can directly act on vascular smooth muscle cells to produce a series of changes that affect the structure of blood vessels. 4, excessive amniotic fluid: the incidence of 8%-30%. The reasons are: high blood sugar in amniotic fluid, stimulating amniotic secretion; high fetal blood sugar level, hyperosmolar diuresis. Easy to occur premature rupture of fetal membranes, premature delivery. 5, infection: infection during pregnancy and delivery is common, such as intrauterine infection, puerperal infection, urinary system, vagina, urethra, upper respiratory tract infection, etc.. The infection rate is as high as 15%. The reason is that leukocytes are defective in many functions, and chemotaxis, phagocytosis and bactericidal effect are significantly reduced. 6, cesarean section rate, birth canal injury, postpartum bleeding rate increased. The rate of cesarean delivery abroad is 50%-81%. The reasons are huge babies, poor maternal health, prolonged labor or weak postpartum contractions. 7. The incidence of ketosis increases, ketoacidosis in severe cases, and the mortality rate of pregnant women and perinatal children increases. 8, long-term complications: GDM 5-16 years after delivery, about 17-63% will develop type II diabetes; recurrence rate of GDM in another pregnancy up to 52%-69%, and most occur before 24 weeks. offspring of GDM pregnant women have an increased chance of obesity and type II diabetes. (B) the impact of diabetes on the fetus and newborn: 1, fetal malformations: early pregnancy hyperglycemia and ketosis are teratogenic, often multiple malformations, cardiovascular (macrovascular ectopic, atrial and ventricular septal defects), central NS (anencephaly, cerebrospinal bulge, microcephaly), bone (caudal degeneration syndrome), digestive tract (esophageal tracheal fistula, intestinal atresia, anal atresia), pulmonary insufficiency, renal insufficiency , polycystic kidney, etc. Common fetal malformations are currently the main cause of perinatal mortality in pregnant women with diabetes, with an incidence of 6-13% in pregnancies with combined overt diabetes. Fetal insulin is functional at 16 weeks, and maternal hyperglycemia in the middle and late stages leads to fetal hyperglycemia, which stimulates fetal insulin B-cell hyperplasia and hypertrophy, resulting in fetal hyperinsulinemia, with the following effects. 2, giant baby: is the most common complication of GDM pregnant women, the incidence of 15%-50%, and with the late gestational blood sugar level, GDM pregnant women obesity when the incidence of giant baby further increased. gigantic children caused by GDM, often manifest asymmetric trunk development, that is, the abdominal circumference is larger than the head circumference, with subscapular and abdominal subcutaneous fat deposition mainly, so pregnant women Difficult delivery and birth injury chances increase. 3. IUGR: mainly seen in pregnant women with diabetes mellitus with microangiopathy. High blood sugar in early pregnancy has the effect of inhibiting embryonic development, and in addition, if diabetes is combined with microangiopathy, placental vascular abnormalities often occur, resulting in reduced intrauterine blood supply to the fetus and affecting fetal development. 4.Fetal distress and fetal death in utero: Due to the abnormal metabolism of blood sugar, fat, amino acids and ketone bodies of the mother, the fetus is directly affected by the placenta, resulting in acidosis: whether the mother is in hyperglycemia or hypoglycemia, the fetus can be hyperglycemic or hypoglycemic, which can directly damage the fetal brain cell function and lead to fetal hypoxia or fetal death in utero; high blood sugar or combined hypertension can reduce the blood flow of the uteroplacenta; in acidosis In acidosis, maternal hypovolemia and hypotension further reduce intervillous blood flow, and placental damage is also common in diabetes; fetal hyperINS increases metabolic rate and oxygen requirements and develops into acidemia. Therefore, many pregnant women with GDM have had unexplained fetal death in utero in the past, which proved to be the result of undiagnosed GDM and uncontrolled glycemia. When pregnant women combined with ketoacidosis, the fetal mortality rate is up to 50%. 5, fetal erythropoiesis: incidence of 30%, intrauterine hypoxia induced erythropoietin increase, stimulating bone marrow hematopoiesis, resulting in increased fetal erythropoiesis, manifested as polycythemia (purple), the light need for transfusion, heavy small amount of blood release. 6, neonatal pulmonary hyaline membrane disease (RDS): also known as neonatal respiratory distress syndrome. The cause is: hyperinsulinemia reduces the production and secretion of lung surface active substances and delays the maturation of fetal lung, which is a serious complication of neonatal disease. Its occurrence is closely related to maternal glycemic control and the number of weeks of termination of pregnancy. 7, neonatal hypoglycemia: the incidence is 20%-30%, and up to 50%-70% in pregnant women with type I diabetes, mostly occurring 1-2 hours after birth. 8, neonatal hypertrophic cardiomyopathy: the incidence of 10%-20%, high insulin leads to myocardial fat, glycogen deposition, mainly seen in pregnant women with unsatisfactory glycemic control delivery of huge children. Echocardiography shows heart enlargement, septal thickening, myocardial hypertrophy, only a few newborns show respiratory distress, severe cases will occur heart failure, most newborns heart enlargement can be normalized in 6 weeks. 9, neonatal hyperbilirubinemia: the reason is the increase of fetal erythrocytes; in addition, huge children have subcutaneous hemorrhage caused by birth injuries, a large number of red blood cell destruction after birth, increased bilirubin production; premature babies or hypoglycemia when the bilirubin combination in the liver is affected. Such patients account for 30%. 10, neonatal low calcium, magnesium: low calcium cause may be related to the reduction of parathyroid hormone production; low blood calcium incidence of 10%-15%, can occur in convulsions (except hypoglycemia first). Low magnesium is associated with low blood magnesium in pregnant women with diabetes. Long-term effects: The offspring of diabetic mothers can develop obesity and abnormal glucose tolerance in adolescence, and have an increased risk of developing diabetes, hypertension and coronary heart disease in adulthood. Offspring with gestational diabetes have high birth weight and high body mass index (BMI) in childhood, and the incidence of diabetes in childhood and early adulthood is 7 to 20 times higher than in the offspring of normal pregnant women. The effects of gestational diabetes on the offspring are a vicious cycle, with consequences extending beyond the neonatal period. The offspring of women who deliver with gestational diabetes are at risk of developing diabetes in their reproductive years.