There are two types of diabetes mellitus during pregnancy, one is diabetes mellitus diagnosed before pregnancy, called “diabetes mellitus combined with pregnancy”; the other is diabetes mellitus with normal glucose metabolism before pregnancy or potentially reduced glucose tolerance, but only developed or diagnosed during pregnancy, also known as “gestational diabetes mellitus (GDM)”. “GDM. The incidence of GDM is reported to be 1%-14% in the world, and 1%-5% in China, with a significant increase in recent years. most patients with GDM can return to normal glucose metabolism after delivery, but have an increased chance of developing type II diabetes in the future. The clinical course of pregnant women with diabetes mellitus is complex, and both mother and child are at risk, so attention should be paid.
Etiology
In the early and middle stages of pregnancy, as the gestational weeks increase, the fetal demand for nutrients increases and glucose is obtained from the mother through the placenta as the main source of fetal energy. The plasma glucose level of pregnant women decreases with the progress of pregnancy, and fasting glucose decreases by about 10%. Reasons: increased fetal glucose acquisition from the mother; increased renal plasma flow and glomerular filtration rate during pregnancy, but the renal tubular reabsorption rate of sugar cannot be increased accordingly, resulting in increased glucose excretion in some pregnant women; estrogen and progesterone increase the maternal utilization of glucose. Therefore, the ability of pregnant women to clear glucose during fasting is enhanced compared with non-pregnancy. The fasting glucose of pregnant women is lower than that of non-pregnant women, which is also the pathological basis for the vulnerability of pregnant women to hypoglycemia and ketoacidosis during prolonged fasting. In the middle and late stages of pregnancy, the anti-insulin-like substances in pregnant women increase, such as placental lactogen, estrogen, progesterone, cortisol and placental insulinase, which make the sensitivity of pregnant women to insulin decrease with the increase of gestational weeks. In order to maintain normal glucose metabolism level, insulin requirement must increase accordingly. For pregnant women with limited insulin secretion, pregnancy cannot compensate for this physiological change and make blood glucose rise, making the existing diabetes aggravated or GDM appear.
1.The effect of pregnancy on diabetes mellitus
Pregnancy can make latent diabetes manifest, make GDM occur in pregnant women without previous diabetes, and aggravate the condition of existing diabetic patients. Fasting blood sugar is low in early pregnancy, and some patients may develop hypoglycemia if the insulin dosage is not adjusted in time for pregnant women treated with insulin. As pregnancy progresses, anti-insulin-like substances increase and insulin dosage needs to be increased continuously. During delivery, physical exertion is high and the amount of food eaten is low. If the insulin dosage is not reduced in time, hypoglycemia may easily occur. After delivery, the placenta is expelled from the body and the anti-insulin substances secreted by the placenta disappear rapidly, so the insulin dosage should be reduced immediately. Due to the complex changes of glucose metabolism during pregnancy, if the insulin dosage is not adjusted in time for pregnant women treated with insulin, some patients may experience hypoglycemia or hyperglycemia, which may even lead to hypoglycemic coma and ketoacidosis in serious cases.
2.The effect of diabetes on pregnancy
The impact of gestational diabetes on mother and child and the degree of impact depends on the condition of diabetes and the level of blood glucose control. If the disease is severe or poorly controlled, it will have a great impact on the mother and child, and the near-term and long-term complications of the mother and child will remain high.
Clinical manifestations
Three symptoms of polyhydramnios (polyhydramnios, polyphagia, polyuria) during pregnancy, or recurrent episodes of vulvar and vaginal pseudomelanotic infections, maternal weight >90 kg, this pregnancy is complicated by hyperhydramnios or giant fetus.
Examination
1. Urine sugar measurement
Those with positive urine sugar should not only consider physiological diabetes during pregnancy, but should further do fasting glucose test and sugar screening test.
2.Fasting blood sugar measurement
Two or more times fasting blood glucose ≥5, 8mmol/L can be diagnosed as diabetes.
3.Glucose screening test
Our scholars suggest that GDM screening should be performed at 24-28 weeks of gestation. 50g of glucose powder dissolved in 200ml of water and taken within 5 minutes, followed by 1 hour blood glucose value ≥7, 8mmol/L is positive for sugar screening, and fasting blood glucose should be checked. Abnormal fasting blood glucose can be diagnosed as diabetes, and those with normal fasting blood glucose will then undergo glucose tolerance test (OGTT).
4.OGTT
China mostly uses 75g glucose tolerance test, which means after 12 hours of fasting, 75g of glucose is taken orally, and its normal upper limit is: fasting 5, 6mmol/L, 1 hour 10, 3mmol/L, 2 hours 8, 6mmo1/L, 3 hours 6, 7mmol/L. If two or more of them reach or exceed the normal value, gestational diabetes can be diagnosed. Only 1 item above the normal value is diagnosed as abnormal glucose tolerance.
Treatment
1. Indicators of whether a diabetic patient can be pregnant
(1) The severity of diabetes mellitus should be determined before pregnancy; once a pregnancy occurs, the risk to the mother and child is greater for class D, F and R diabetes mellitus. If a pregnancy has already occurred, it should be terminated as soon as possible.
(2) Those with mild organic lesions and good glycemic control can continue pregnancy under active treatment and close supervision.
(3) Strictly control the blood glucose value with the assistance of physicians from before conception to ensure that the blood glucose is within the normal range before conception, during pregnancy and during delivery.
2. Management of pregnant women with abnormal glucose metabolism
(1) Satisfactory standard of blood glucose control during pregnancy Pregnant women have no obvious hunger and fasting blood glucose is controlled at 3,3~5,6 mmol/L; 30 minutes before meal: 3,3~5,8 mmo1/L; 2 hours after meal: 4,4~6,7 mmol/L; night: 4,4~6,7 mmol/L.
(2) Dietary treatment Dietary control is important. The ideal goal of diet control is to ensure and provide the caloric and nutritional needs during pregnancy, but also to avoid the appearance of postprandial hyperglycemia or starvation ketosis, to ensure normal fetal growth and development. Most patients with GDM can control their blood glucose in a satisfactory range with reasonable dietary control and appropriate exercise therapy. Pregnant women with diabetes in early pregnancy need the same number of calories as before pregnancy. After mid-pregnancy, the weekly calories increase by 3% to 8%. Among them, sugar accounts for 40% to 50%, protein accounts for 20% to 30% and fat accounts for 30% to 40%. Control the blood glucose value of 1 hour after meal to be below 8mmol/L. However, attention should be paid to avoid excessive control of diet, otherwise it will lead to starvation ketosis and fetal growth restriction in pregnant women.
(3) Drug therapy The safety and effectiveness of oral hypoglycemic drugs applied in pregnancy have not been sufficiently confirmed and are not recommended at present. Insulin is a large molecular protein that does not pass through the placenta. For diabetes mellitus that cannot be controlled by dietary treatment, insulin is the main therapeutic drug.
Insulin dosage varies greatly among individuals, and there is no uniform standard for reference. Generally, the dosage starts from a small amount and is adjusted according to the condition, the progress of pregnancy and blood glucose value, in order to control blood glucose at normal level. The body’s demand for insulin is different in different periods of pregnancy: ① For patients who used insulin to control blood sugar before pregnancy, the amount of insulin dosage should be reduced in time according to the blood glucose monitoring as the amount of food is reduced in early pregnancy due to early pregnancy reaction. ② As pregnancy progresses, the secretion of anti-insulin hormone gradually increases, and the insulin requirement in the middle and late pregnancy often increases to different degrees. Insulin dosage peaks at 32 to 36 weeks of gestation and decreases slightly after 36 weeks of gestation, especially at night. The decrease in insulin requirement in late pregnancy is not necessarily due to placental hypoglycemia, but may be related to increased fetal utilization of blood glucose, and pregnancy can be continued with enhanced fetal monitoring.
(4) Treatment of gestational diabetic ketoacidosis While monitoring blood gas, blood glucose and electrolytes and giving appropriate treatment, it is recommended to apply small doses of regular insulin intravenously. Monitor blood glucose every 1 to 2 hours. For blood glucose >13,9mmol/L, insulin should be added to 0,9% sodium chloride injection intravenously. Blood glucose ≤13,9mmo1/L, start to add insulin to 5% dextrose sodium chloride injection intravenously, and can be changed to subcutaneous injection after the ketone body turns negative.
3. Maternal and child monitoring during pregnancy
Gestational reaction in early pregnancy may bring difficulties to blood glucose control, and blood glucose changes should be closely monitored and insulin dosage should be adjusted in time to prevent hypoglycemia. It should be checked once a week until the 10th week of pregnancy. In the middle of pregnancy, it should be checked once every two weeks. Generally, the insulin requirement starts to increase at 20 weeks of pregnancy, and timely adjustment is needed. Kidney function and glycated hemoglobin level should be measured monthly, and fundus examination should be performed at the same time. After 32 weeks of gestation, weekly check-ups should be performed. Pay attention to blood pressure, edema, and urine protein. Pay attention to the monitoring of fetal development, fetal maturity, fetal placental function, etc., and hospitalize early if necessary.
4. Timing of delivery
In principle, the timing of termination of pregnancy should be postponed as much as possible. If the blood glucose is well controlled, there are no comorbidities in late pregnancy and the fetus is in good intrauterine condition, you should wait until 38-39 weeks of gestation to terminate the pregnancy. If the blood glucose control is unsatisfactory, with vascular lesions, combined with severe pre-eclampsia, serious infection, fetal growth restriction, fetal distress, amniotic fluid should be extracted early to understand the maturity of fetal lung, and dexamethasone should be injected to promote fetal lung maturity, and the pregnancy should be terminated immediately after fetal lung maturity.
5. Mode of delivery
Gestational diabetes mellitus is not an indication for cesarean delivery, but if there is a huge fetus, placental dysfunction, abnormal fetal position or other obstetric indications, cesarean delivery should be performed. For pregnant women with diabetes >10 years, with retinopathy and renal impairment, severe pre-eclampsia, history of stillbirth and stillbirth, the indications for cesarean delivery should be relaxed.
6.Treatment during delivery
(1) General treatment Pay attention to rest and sedation, give appropriate diet, closely observe the changes of blood sugar, urine glucose and ketone body, adjust insulin dosage in time, and strengthen fetal monitoring.
(2) Vaginal delivery Emotional tension and pain during labor can cause blood sugar fluctuations. Insulin dosage is not easy to control, so strict control of blood glucose level during labor is very important for both mother and child. Diabetic diet is still used after delivery. In general, subcutaneous injection of regular insulin should be stopped during labor, and intravenous infusion of 0,9% sodium chloride injection plus regular insulin should be given, and the speed of intravenous infusion should be adjusted according to the blood glucose value measured during labor. Also recheck blood glucose and continue to adjust if abnormal blood glucose is found. Labor should be ended within 12 hours, and prolonged labor increases the risk of ketoacidosis, fetal hypoxia and infection.
(3) Cesarean delivery Stop applying pre-dinner zinc arginine insulin the day before surgery and stop subcutaneous insulin injection on the day of surgery. Blood glucose, urine glucose and urine ketone bodies are usually monitored in the morning. According to their fasting blood glucose level and daily insulin dosage, change to low-dose insulin continuous intravenous drip. Try to keep intraoperative blood glucose control at 6,67 to 10,0 mmol/L. Measure blood glucose every 2 to 4 hours after surgery until diet resumes.
(4) Postpartum treatment After the placenta is expelled during the puerperium, the anti-insulin substance in the body is rapidly reduced, and most patients with GDM no longer need insulin after delivery, and only a few patients still need insulin therapy. The insulin dosage should be reduced to 1/3 to 1/2 of what it was before delivery, and the dosage should be adjusted according to the postpartum fasting glucose value. Most insulin dosage gradually returns to the pre-pregnancy level 1 to 2 weeks after delivery. OGTT will be performed at 6 to 12 weeks after delivery, and if it is still abnormal, it may be a patient with prenatal missed diabetes.
(5) Treatment of newborns at birth Umbilical cord blood should be kept at birth for measurement of blood glucose, insulin, bilirubin, hematocrit, hemoglobin, calcium, phosphorus and magnesium. Regardless of the condition of the infant at birth, it should be regarded as a high-risk neonate, especially those with unsatisfactory glycemic control during pregnancy, who need to be monitored, pay attention to warmth and oxygen, focus on preventing neonatal hypoglycemia, and should be given regular glucose drops while breastfeeding.