Monitoring of objective indicators of fetal status with the help of ultrasound

The possibilities of the ultrasonic method are as follows:

Determination of the position of the fetus and the prevalent color. Difficulties with the definition of the presenting part are usually observed in obese women, with polyhydramnios, with strong and frequent bouts. In such situations, with a high-standing head, even a vaginal examination does not resolve doubts.

Fetal biometry. Prenatal determination of fetal mass is of great importance for the doctor leading the delivery. Knowing the estimated weight of the fetus is especially important in pelvic presentation, if there are indications for premature termination of pregnancy. For this, there is a method proposed by AV Rudakov, who unfortunately, with polyhydramnios and obesity, gives a large number of diagnostic errors.

To estimate the weight of the fetus with ultrasound, it is necessary to measure the biparietal size of the head sufficiently accurately. As a guide, this size is chosen because it is the most informative. First, the ratio of biparietal size to fetal weight, in comparison with the rest of the measured sizes, has the most constant numerical values; secondly, the skull bones only in the temporal parietal region are located at a comparatively large distance in parallel and therefore a clear image of the oval is obtained. We used seven formulas, of which we chose the most reliable.

With a small fetal size, the predicted mass, as a rule, was greater than the actual mass; In large fruits, reverse relationships were observed, ie, it should be remembered that with small fruits their true mass is greater than predicted, with large fruits - less. The decisive importance in determining the mass of the fetus is not the nature of the measured parameters, but the accuracy of measurements; with fruits weighing up to 4000 g, a careful measurement of the biparietal size allows the mass to be predicted with sufficient accuracy. The questions of forecasting the mass of large fruits require further development.

Determination of the ratio between the size of the fetal head and the size of the mother's pelvis. When using the ultrasound method, you can simultaneously see the symphysis and promontory and thereby measure the true conjugate with a high-standing head. Measuring the biparietal size of the head in the future, we can estimate the likelihood of a discrepancy between the size of the pelvis of the mother and the fetal head. It is especially important to know with pelvic fetal presentations or diabetes maternal diabetes, when even a small degree of mismatch can lead to severe fetal and newborn baby injuries or stillbirth.

Definition of multiple pregnancies. The diagnosis of multiple births during labor is significantly less important than during pregnancy. Ultrasound is the most accurate method for diagnosing multiple pregnancies, starting at 6 weeks ultrasound in 100% establishes a multiple pregnancy. It allows not only to carry out early diagnosis of multiple pregnancies, but also to determine the nature of fruit development by biometric indicators, the amount of placenta (mono- or dichoric type of placentation) and amniotic cavities (mono- or diamniotic twins).

Ultrasound examination allows to differentiate multiple pregnancies from polyhydramnios, bladder drift and large fetus. The most optimal method of organizing early diagnosis of multiple pregnancies is to perform ultrasound diagnosis (screening), that is, a mass examination of all women in a certain region in 16-20 weeks of gestation, which simultaneously allows to identify fetal development abnormalities, placental localization, etc.

Timely determination of the position and position of the fetuses is shown in the plan for determining the indications for cesarean section (transverse position, pelvic presentation, etc.).

In the past, the main method of diagnosing multiple pregnancies in unclear cases was X-ray, as well as background and electrocardiography of the fruit. The first method is undesirable to some extent, and the second method is not very informative and can be used mainly in late pregnancy.

Definition of polyhydramnios. Much water is physiological for the beginning of the second trimester of pregnancy. With expressed polyhydramnios, it is difficult to determine the gestation period, the size of the fetus and the presence of malformations. Diagnosis is based on the detection on the echogram between the uterine wall and the fruit of a large zone without reflections; the image of the parts of the fruit and head is unusually loose at some distance from the image of the trunk.

Determination of fetal development abnormalities. It is difficult to overestimate the importance and necessity of possibly early prenatal diagnosis of pronounced fetal development anomalies. In such situations, pregnancy should be terminated prematurely, especially when it occurs with complications. With the timely diagnosis of anomalies, it is possible to save a woman from a number of surgical interventions during childbirth, especially - cesarean section. With the help of ultrasound, defects in the skull bones, as well as other malformations of the fetus (fetal ascites, fetal kidney fetal polycystosis, fetal abdominal swelling, anomalies of the genitourinary system, etc.) are sufficiently reliably diagnosed.

Anencephaly is best seen in the longitudinal plane, since in the transverse position the image of the base of the skull can simulate a circular image of the head. It is important to obtain a skull base image, after which an incorrect configuration of the head is easily detected. In such cases, polyhydramnios are often found.

To diagnose hydrocephalus, it is necessary to determine the biparietal size of the head; the minimum value for diagnosis in term of full term pregnancy is 11 cm. In addition, when comparing the dimensions of the head and thorax, disproportion is determined. On the same basis, a diagnosis of microcephaly is also established.

Determination of the location of the placenta. The normal duration of the birth act, a low percentage of rhythm-enhancing therapy, a lower incidence of surgical interventions in childbirth, pathological hemorrhage in the consecutive and early postpartum periods, and the birth of children in a state of hypoxia when the placenta is localized in the uterus body makes it more favorable. It is recommended that when the mother is placenta is localized in the uterus, the weakness of labor activity with another obstetric or extragenital pathology should promptly raise the issue of delivery by cesarean section.

When using the ultrasound method, the diagnosis is made on the basis of the following symptoms:

• a lot of point additional echoes are determined between the fetus and the uterine wall;
• the image of the edge of the placenta facing the fetus has an intermittent line (reflection from the chorionic plate), especially when the placenta is located on the front wall. Simultaneously determine the degree of maturity of the placenta. On the basis of changes in the echogenicity of the villous chorion, three stages of maturity are distinguished at different stages of pregnancy. In uncomplicated pregnancy, each stage corresponds to a certain period (stage I - 12-31 weeks, II stage - 32-36 weeks, III stage - 37-40 weeks). At a toxicosis of pregnant women at half of them mismatch of an echogenicity of a chorion (acoustic density) to gestation term is observed. For severe toxicosis of pregnant women, premature echogenicity of the chorion is most typical.

The main indications for placentography are:

• Suspicion of placenta previa. Its image is particularly clear with a full bladder and a highly standing presenting part (head), if the placenta is not located on the posterior surface of the uterus;
• Suspicion of premature detachment of the normally located placenta. The success of the diagnosis depends on the degree of placental abruption;
• In the presence of scars on the uterus after surgery, if the placenta is located on the front wall of the uterus, ie, in the area where there is a scar. These women during labor often identify signs of bankruptcy.

[1], [2], [3], [4], [5]