In newborns from mothers of patients with diabetes (NMD), the risk of developing congenital anomalies increases 3 times compared with 1-2% of the basic risk for all newborns. Most often, heart defects and abnormalities in the development of limbs occur. A typical, but rather rare anomaly is agenesis of the sacrum. More often, excessive fetal growth or macrosomia is noted with a fetal weight of more than 4,500 g, which is the result of an excess supply of glucose to the fetus through the uteroplacental system.
The large size of the fetus can lead to clinical mismatch with the size of the pelvis of the mother, which will require delivery by cesarean section. In childbirth through the natural birth canal, the danger of dystocia of the shoulders is great.
Shortly after birth , NMD causes neonatal hypoglycemia. It is the result of changing living conditions. Being in the womb, the fetus receives increased amounts of glucose and responds with increased production of insulin for its absorption. After birth, glucose flow stops, and a high concentration of insulin causes a significant drop in glucose levels. Newborns of this group also have an increased risk of developing neonatal hyperbilirubinemia, hypocalcemia and polycythemia.
Another complication of pregnancy combined with diabetes is polyhydramnios, that is, an increase in the amount of amniotic fluid in excess of 2 liters (hydroamnion or polyhydroamnion). It is observed in about 10% of cases. An increase in the volume of amniotic fluid and the size of the uterus increases the risk of premature detachment of the placenta and premature birth and is a predisposing factor for the development of postpartum uterine atony.
The frequency of spontaneous abortions in ordinary pregnant women and in pregnant women with diabetes that responds well to treatment is approximately the same. But this indicator increases significantly with inadequate correction. In the latter case, the risk of fetal death and stillbirth is also increased.
In NMD, respiratory distress syndrome develops 5–6 times more often, and the usual tests for assessing lung maturity are of little prognostic value in these cases.
Laboratory diagnosis of diabetes during pregnancy.
About 1% of women suffer from diabetes before they become pregnant. In these patients, obstetric medical observation and treatment should begin before pregnancy. Its task is to improve the course of diabetes and the maximum possible optimization of carbohydrate metabolism. There is no consensus on how such a tactic can reduce the risk of developing congenital malformations of the fetus. However, a number of other positive indicators of the condition of the patient and the fetus confirm the rationality and effectiveness of such a tactic of diabetes management.
Gestational diabetes is usually diagnosed during a routine examination of pregnant women. Certain risk factors make it possible to predict its development with a high degree of probability. These factors include previous births of children weighing more than 4000 g, repeated spontaneous abortions, unexplained stillbirths, diabetes in immediate relatives, obesity, and persistent glucosuria. However, 50% of patients with gestational diabetes did not have any risk factors. This circumstance necessitates the study of carbohydrate metabolism in all pregnant women.
The most common glucose tolerance test does not require any patient preparation. It consists of the following: the patient drinks a solution containing 50 g of glucose (glucol) and after 1 hour the level of glucose in the blood plasma is determined. The upper limit of normal for a 1-hour glucose test is 1.4 g / l. If the result of the study exceeds this indicator, a 3-hour glucose tolerance test is recommended. First, within 3 days, the patient takes a certain amount of carbohydrates (on average 150 g / day).
Then the test itself begins : a) the level of fasting glycemia is determined; b) a solution containing 100 g of glucose is taken orally; c) after 1, 2, 3 hours, glycemia levels are re-determined. The upper limits of the norm are given in the table. Two or more indicators exceeding the norm indicate the presence of gestational diabetes. One excess indicator suggests a disease and requires re-examination after 4-6 weeks (depending on gestational age and time of the initial examination). All standard indicators are given in the table.
If the patient has not identified risk factors , the first 1-hour glucose tolerance test is usually carried out between 24 and 28 weeks of pregnancy, because it is at this time that symptoms of glucose tolerance impairment begin to appear. When the patient has risk factors, the examination is performed with antenatal care. If it does not reveal a pathology, it should be repeated at the beginning of the third trimester of pregnancy. This examination tactic allows you to identify abnormalities in approximately 15% of pregnant women. Subsequent 3-hour testing of this group of patients establishes the presence of gestational diabetes in 15% of them.