What Is the Relationship Between Gestational Diabetes and Insulin?

There are two cases of diabetes during pregnancy, one is diagnosed with diabetes before pregnancy, called "diabetes with pregnancy"; the other is diabetes with normal glucose metabolism or impaired glucose tolerance before pregnancy, which occurs or is diagnosed during pregnancy , Also known as "gestational diabetes (GDM)." More than 80% of diabetic pregnant women are GDM, and less than 20% of diabetic pregnant women. The incidence of GDM in countries around the world is reported as 1% to 14%, and the incidence rate in China is 1% to 5%, which has increased significantly in recent years. Most of GDM patients' glucose metabolism can return to normal after delivery, but the chance of developing type 2 diabetes will increase in the future. The clinical experience of diabetic pregnant women is complicated, and both mother and child are at risk.

Basic Information

English name

gestational diabetes mellitus

Visiting department

Obstetrics and Gynecology, Endocrinology

Multiple groups

Pregnant woman

Common causes

May be related to insulin resistance, genetics and other factors

Common symptoms

Symptoms such as polydipsia, polydipsia, polyuria during pregnancy

Causes of gestational diabetes

In the first and second trimester of pregnancy, with the increase of the gestational week, the fetal needs for nutrients increase. Glucose from the mother through the placenta is the main source of fetal energy. The plasma glucose level of pregnant women decreases with the progress of pregnancy, and the fasting blood glucose is reduced by about 10%. Reasons: Fetal glucose from the mother increases; renal plasma flow and glomerular filtration rate increase during pregnancy, but the reabsorption rate of sugar in the renal tubules cannot be increased accordingly, leading to increased glucose excretion in some pregnant women; increased estrogen and progesterone Utilization of glucose by the mother. Therefore, the ability of pregnant women to clear glucose when fasting is enhanced compared to non-pregnant women. The fasting blood glucose of pregnant women is lower than that of non-pregnant women, which is also the pathological basis for the proneness of hypoglycemia and ketoacidosis in pregnant women. In the middle and late stages of pregnancy, the body's anti-insulin-like substances increase, such as placental lactogen, estrogen, progesterone, cortisol, and placental insulinase, which make pregnant women's sensitivity to insulin decrease with increasing gestational age. To maintain normal glucose metabolism, insulin requirements must be increased accordingly. For pregnant women with restricted insulin secretion, this physiological change cannot compensate for the increase in blood sugar during pregnancy, which exacerbates the original diabetes or GDM.

1. The impact of pregnancy on diabetes

Pregnancy can make recessive diabetes explicit, make GDM occur in pregnant women without diabetes, and make the original diabetic patients worse. In early pregnancy, fasting blood glucose is low. If insulin treatment is not used to adjust the insulin dosage in time, some patients may have hypoglycemia. As pregnancy progresses, anti-insulin-like substances increase, and the amount of insulin needs to increase. In the process of childbirth, the physical exertion is large, and the food intake is small. If insulin consumption is not reduced in time, hypoglycemia is prone to occur. After delivery, the placenta is excreted from the body, and the anti-insulin substances secreted by the placenta disappear rapidly, and the amount of insulin should be reduced immediately. Due to the complex changes in glucose metabolism during pregnancy, if pregnant women who use insulin treatment do not adjust the insulin dosage in time, some patients may have hypoglycemia or hyperglycemia, and severe cases may even lead to hypoglycemic coma and ketoacidosis.

2. The impact of diabetes on pregnancy

The effect and degree of pregnancy and diabetes on mothers and children depends on the condition of diabetes and blood glucose control. Those with a severe condition or poor blood glucose control have a great impact on the mother and child, and the near-term and long-term complications of the mother and child are still high.

Clinical manifestations of gestational diabetes

1. Gestational diabetes usually does not have obvious symptoms of three more and one less (more drinking, more food, more urine, weight loss).

2. Vulvar itching, repeated candida infections.

3. It was found that the fetus was too large and had too much amniotic fluid during pregnancy.

4. Anyone with a family history of diabetes, a pre-pregnancy weight 90kg, a pregnant woman's birth weight 4000g, a pregnant woman with polycystic ovary syndrome, an unexplained abortion, a stillbirth, a large child or a deformed child with a birth history People should be alert to diabetes.

Gestational diabetes examination

All pregnant women from 24 to 28 weeks of pregnancy should be screened for sugar.

1. Fasting blood glucose measurement (FDG)

FDG 5.1mmol / L can directly diagnose GDM without the need for an oral glucose tolerance test (OGTT); FDG <4.4mmol / L, the possibility of GDM is extremely small, and OGTT can be temporarily suspended. When FDG4.4mmol / L and <5.1mmol / L, OGTT should be performed as soon as possible.

2. Oral glucose tolerance test ( OGTT )

At present, China uses OGTT of 75g glucose to diagnose diabetes. Diagnostic criteria: fast for at least 8 hours. During the test, 300 ml of a liquid containing 75 g of glucose was taken orally within 5 minutes, and the blood glucose levels of pregnant women before and after taking sugar were measured. The three blood glucose levels should be lower than 5.1mmol / L, 10.0mmol / L, 8.5mmol / L (92mg / dL, 180mg / dL, 153mg / dL), and any one of them can meet the above criteria to diagnose GDM. .

Gestational diabetes treatment

1. Indicators of whether a diabetic patient can become pregnant

(1) Diabetics should determine the severity of diabetes before pregnancy. Once D, F, R grade diabetes is pregnant, the danger to mother and child is greater, should be contraceptive, not pregnant. If pregnancy has been terminated as soon as possible.

(2) Those with less organic lesions and better blood glucose control can continue their pregnancy under active treatment and close monitoring.

(3) From pre-pregnancy, strictly control the blood glucose level with the assistance of a physician to ensure that the blood glucose before pregnancy, pregnancy and childbirth is within the normal range.

2. Management of pregnant women with abnormal glucose metabolism

(1) Satisfactory standard of blood glucose control during pregnancy. Pregnant women have no obvious hunger, fasting blood glucose is controlled at 3.3 5.6mmol / L; 30 minutes before meal: 3.3 5.8mmo1 / L; 2 hours after meal: 4.4 6.7mmol / L; At night: 4.4 to 6.7 mmol / L.

(2) Diet therapy Diet control is important. The ideal diet control goal is to not only ensure and provide calories and nutritional requirements during pregnancy, but also to avoid the occurrence of postprandial hyperglycemia or hunger ketosis and ensure normal fetal growth and development. Most patients with GDM can control blood sugar to a satisfactory range after reasonable diet control and proper exercise treatment. Pregnant women with early pregnancy diabetes need the same calories as before pregnancy. After the second trimester, the weekly calories increase by 3% to 8%. Among them, carbohydrates account for 40% to 50%, protein accounts for 20% to 30%, and fat accounts for 30% to 40%. Control the blood glucose level at 1 hour after a meal to be less than 8mmol / L. However, care should be taken to avoid over-controlling the diet, or it will lead to hungry ketosis and fetal growth restriction in pregnant women.

(3) Drug treatment The safety and effectiveness of oral hypoglycemic agents in pregnancy have not been sufficiently confirmed and are not currently recommended. Insulin is a large-molecular-weight protein that does not pass through the placenta. It is the main treatment for diabetes that cannot be controlled by diet.

Individual insulin dosage varies widely, and there is no uniform standard for reference. Generally start from a small dose and adjust it according to the condition, the progress of pregnancy and the blood sugar value, and strive to control blood sugar at normal levels. The body's needs for insulin are different at different stages of pregnancy: Patients who use insulin to control blood sugar before pregnancy have reduced their intake of food due to early pregnancy in early pregnancy, and need to reduce the amount of insulin in time according to blood glucose monitoring. With the progress of pregnancy, the secretion of anti-insulin hormones gradually increases, and insulin requirements in the middle and late stages of pregnancy often increase to varying degrees. Insulin consumption peaks at 32 to 36 weeks of pregnancy, and decreases slightly after 36 weeks of pregnancy, especially at night. Decreased insulin requirement in late pregnancy is not necessarily a decrease in placental function, and may be related to an increase in the use of blood glucose by the fetus. Pregnancy can be continued with enhanced fetal monitoring.

(4) Treatment of gestational diabetic ketoacidosis While monitoring blood gas, blood sugar, electrolytes and giving corresponding treatment, it is advisable to use a small dose 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. For blood glucose 13.9mmo1 / L, start to add insulin to 5% glucose sodium chloride injection by intravenous drip. After the ketone body becomes negative, it can be changed to subcutaneous injection.

3. Maternal and child care during pregnancy

Early pregnancy response may bring difficulties to blood glucose control, and blood glucose changes should be closely monitored and insulin dosage adjusted in time to prevent hypoglycemia. Check once a week until the 10th week of pregnancy. The second trimester of pregnancy should be checked every two weeks. Generally, insulin requirements begin to increase at 20 weeks of pregnancy and need to be adjusted in time. Renal function and glycated hemoglobin content were measured monthly, and fundus examination was performed at the same time. It should be checked weekly after 32 weeks of pregnancy. Pay attention to blood pressure, edema, and urine protein. Pay attention to the monitoring of fetal development, fetal maturity, fetal placental function, etc., and early hospitalization if necessary.

4. Timing of childbirth

The principle is to try to delay the termination of pregnancy. Glucose control is good, no complications in the third trimester, and the fetal condition is good. Wait until the pregnancy is 38 to 39 weeks to terminate the pregnancy. Unsatisfactory blood glucose control, with vascular disease, combined with severe preeclampsia, severe infections, fetal growth restriction, fetal distress, early amniotic fluid should be drawn to understand fetal lung maturity, and dexamethasone injection promotes fetal lung maturation, fetal lung The pregnancy should be terminated immediately after maturity.

5. Delivery method

Gestational diabetes mellitus itself is not an indication for cesarean section. Patients with a large fetus, placental dysfunction, abnormal fetal position, or other obstetric indicators should undergo cesarean section. For pregnant women with a course of diabetes> 10 years, accompanied by retinopathy and renal impairment, severe preeclampsia, stillbirth and stillbirth history, the indication for cesarean section should be relaxed.

6. Management during delivery

(1) General treatment Pay attention to rest and sedation, give proper diet, closely observe changes in 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 make blood sugar fluctuate. The amount of insulin is not easy to grasp, and strict control of the blood glucose level at birth is very important for both mothers and children. A diabetic diet is still used after labor. Subcutaneous injection of regular insulin should generally be discontinued during the delivery process. Intravenous infusion of 0.9% sodium chloride injection plus regular insulin should be used, and the intravenous infusion rate should be adjusted based on the blood glucose measured during the delivery process. At the same time, the blood glucose was reviewed, and it was found that the blood glucose was abnormally adjusted. Delivery should end within 12 hours, and the length of the labor increases the risk of ketoacidosis, fetal hypoxia, and infection.

(3) Cesarean section The application of protamine zinc insulin before dinner is stopped on the day before surgery, and the subcutaneous injection of insulin is stopped on the day of surgery. Blood sugar, urine sugar, and ketone body are generally monitored in the morning. According to his fasting blood glucose level and daily insulin dosage, he switched to a small-dose continuous insulin drip. Try to control the intraoperative blood glucose between 6.67 and 10.0 mmol / L. Blood glucose was measured every 2 to 4 hours after the operation until the diet recovered.

(4) Postpartum treatment After discharge of placenta during puerperium, the body's anti-insulin substances decrease rapidly. Most GDM patients no longer need insulin after delivery, and only a few patients still need insulin treatment. The dosage of insulin should be reduced to 1/3 to 1/2 before delivery, and the dosage should be adjusted according to the postpartum fasting blood glucose value. Most insulin doses gradually return to pre-pregnancy levels within 1 to 2 weeks after delivery. OGTT is performed 6 to 12 weeks postpartum. If the abnormality persists, it may be a pre-diagnosed diabetic patient.

(5) Handling at birth The umbilical cord blood should be kept at birth. The blood glucose, insulin, bilirubin, hematocrit, hemoglobin, calcium, phosphorus and magnesium should be measured. Regardless of the status of the baby at birth, it should be regarded as a high-risk newborn, especially those who are not satisfied with the control of blood glucose during pregnancy. They should be monitored, keep warm and oxygen, and focus on preventing hypoglycemia in the newborn. Glucose solution.