Diagnosis of pregnancy and its violation

The importance of radiation methods in the diagnosis of pregnancy and its disorders is very high. It suffices to list the main problems of radiation research.

First, the confirmation of the fact of pregnancy, the location of the fetus (in the uterus or abdominal cavity), the determination of the number of fetuses, the age and sex of the fetus and the correctness of its development, recognition of fetal anomalies and its death. Secondly, an assessment of the position, magnitude and condition of the placenta and amnion. Third, measurement of the pelvis and evaluation of the condition of the birth canal (in particular, the elimination of obstructions to the birth act, for example, pelvic deformities, ovarian cysts, etc.). Fourth, the definition of the hormonal status of a pregnant woman.

Morphological and functional changes in the body during pregnancy are sensitively captured by radiation methods. In the physiological course of pregnancy, the zones of hyperthermia in the area of the mammary glands, the anterior abdominal wall (especially above the pubis), and the neck are determined on thermograms already in the early period. Even more sensitive are radioimmune tests that reflect hormonal changes in the body. However, the leading role in radiation diagnosis acquired ultrasonic methods. Currently, most medical institutions carry out screening programs for all pregnant women. Based on the combination of clinical, ultrasound and radioimmunological data, a conclusion is made about the nature of the course of pregnancy and the need for any therapeutic and prophylactic measures.

Sonography is one of the most accurate methods of establishing the fact of pregnancy. Already at the 5th-6th week of pregnancy on sonograms an image of the fetal egg appears. It is located in the uterus asymmetrically and has the appearance of a cavity with an echo-negative center and an echogenic rim.

In normal pregnancy, unlike the ectopic contour, the fetal sac consists of two rings inscribed in each other. At the 6th week the fetal egg occupies 1/3 of the volume of the uterine cavity, by 8-9-ies - almost half of it. There is an uneven thickness of the villous shell, caused by the formation of the placenta. The details of the image are best distinguished by transvaginal sonography. From the 8-9th week, the yolk sac starts to be visualized as a spherical formation with a diameter of 5-6 mm. The image of the embryo can be obtained at 7-8 weeks, and this is a sign of a normal course of pregnancy. The embryo is located near the wall of the amnion, it is 9-10 mm in size. During this period, one can already study the activity of his heart.

As the embryo develops further, all of its basic structures appear. On the 9-10th week, the head and body begin to appear, on the 10-11th - the limbs and the umbilical cord. At the 12th week the ultrasound signal from the middle structures of the brain (M-echo) is captured. M-echo serves as a guide in the diagnosis of a number of pathological changes in the fetal brain. The placenta is quite clearly discernible at the 8th-10th week; at the 12th week it has the appearance of a homogeneous echogenic mass.

With the help of ultrasound in the regime of energy Doppler, the activity of the heart and stomach is studied from the 10th week of pregnancy. Approximately at the same time, slow movements of the fetus are recorded. Later, rapid jerky movements appear, accompanied by limb movements. Incidentally, we note that on the radiographs of the part of the fetal skeleton are visible no earlier than the 13-14th week.

The gestation period is determined by ultrasound measurement of the uterus, fetal egg and embryo. The uterus begins to increase by 7-10 mm per week from the 7th week of pregnancy. Guided by the results of ultrasonic biometrics, according to special tables it is possible to determine the period of pregnancy in the first trimester with an accuracy of 1 week. Reliable data for this can be obtained by measuring the fetal egg. Its weekly increase is 5 - 8 mm. The accuracy of calculating the gestation period for a fetal egg is ± 4-7 days. An important indicator is also the results of fetometry - the measurement of the fetus, especially in the period between the 10th and 26th weeks. There are tables with different parameters of the fetus in different periods of pregnancy.

There are also tables that summarize the dimensions of the fetus in the X-ray image, as well as the timing of the appearance of ossification points in various bones visible on the radiographs. However, radiography is allowed only for special indications and is absolutely forbidden during the first trimester of pregnancy, when the fetus is particularly sensitive to the effects of ionizing radiation.

In terms of the 24th to 34th week, you can set the sex of the fetus. On sonograms produced during this period, images of the scrotum and penis in the boys are visible. In later terms, to identify these organs is more difficult because of the large size of the fetus and the reduction of the volume of amniotic fluid.

It is important for an obstetrician to know the location and condition of the placenta. The placenta is visible on sonograms at the beginning of the second trimester of pregnancy as a flat echopositive formation of a granular structure. Its border, turned into amniotic waters, is clear, whereas the base facing the uterine wall is not clearly defined. In the third trimester, individual placental segments become visible. The maximum thickness of the placenta - 35-40 mm - is reached by the 35th week of pregnancy. Then the placenta is somewhat thinner and flattened. Compaction at an earlier time is an unfavorable sign. It is observed with polyhydramnios, fetal hypotrophy, fetal hemolytic disease, and some of its anomalies. In all these cases, parallel to the thinning of the placenta, the concentration of placental lactogen and progesterone in the blood decreases.

Of great practical importance is the definition of the relationship between the lower edge of the placenta and the internal throat of the cervix. Normally, this distance should not be less than 7 cm. Otherwise, they speak of a low location or partial presentation of the placenta. These women often have bleeding. In this regard, in the case of a stable position of the placenta near the cervix, the pregnant woman is included in the high-risk group and hospitalized for medical observation 2 weeks before the expected delivery. A special danger with regard to uterine bleeding is the full presentation of the placenta, when the latter overlaps the cervical cervix.

The ultrasonic sign of a threatening miscarriage is a periodically occurring local thickening of the muscular wall of the uterus, which deforms the fetal egg. The symptom of a beginning miscarriage is the detachment of the fetal egg from the uterine wall. This is clearly seen on the sonogram, as there is an echonagic band caused by the outflow of blood. Confirmation of a beginning miscarriage is a decrease in the concentration in the blood of placental lactogen, estriol and progesterone.

One of the most serious complications of pregnancy is intrauterine fetal death. In the radioimmunoassay, a low concentration of placental lactogen and progesterone is detected.

Ultrasound research helps in the diagnosis of ectopic (ectopic) pregnancy. A reliable sign of it is the detection of a fetal egg and an embryo located outside the uterus at "empty", i.e. Not containing these formations, the uterus. If a woman does not have abundant bloody discharge, then you can enter 10 ml of isotonic sodium chloride solution into the cervical canal. With ectopic pregnancy on sonograms clearly echonogativity of the uterine cavity and tubes is clearly visible. Radiographic evidence of ectopic pregnancy is also the location of the fetus outside the uterus.

For midwives, knowledge of the radioimmunological indices of normal and abnormal pregnancy is of considerable importance. During pregnancy, an endocrine system of the fetoplacental complex is formed in the woman's body, which corrects the complex relationship between the mother and the fetus. The main products of the activity of the fetoplacental system are steroidal galactotropic and somatotropic hormones.

The highest value for assessing the function of the placenta and the condition of the fetus is the determination of the level of placental lactogen (PL), alpha-fetoprotein (AFP), progesterone and estriol.

Favorable course of the birth can be prevented by the wrong position of the fetus, mismatch in the size of the fetus, the size of the pelvis, various abnormalities and diseases of the birth canal women. Timely diagnosis of these conditions is carried out by means of ultrasound scanning and magnetic resonance imaging. The possibilities of sonography are discussed above. Here, we note that the use of magnetic resonance imaging opens up wide prospects for the obstetric clinic, since in the analysis of magnetic resonance tomograms it is possible to obtain comprehensive information on the uterus, ovaries, fetal condition, placenta, soft tissues of the birth canal without irradiation of the mother and fetus. In the absence of modern technical means, the size of the pelvis and the position of the fetus can be determined using the X-ray method, including X-ray pelviometry - measurements of the pelvis and fetal head by X-ray patterns. For this purpose, a variety of X-ray methods of measurement have been developed. We emphasize that the direction of the pregnant woman on radiography should be justified and recorded in the polyclinic map or the history of childbirth. In practice, interventional radiation methods of research and correction of the fetal condition are gradually introduced - fetal radiation surgery is being formed. Under the control of ultrasound scanning, early amniocentesis, chorion biopsy, fetal blood sampling (for diagnosis of hemophilia, thalassemia and other lesions), fetal skin biopsy, treatment of obstruction of its urinary tract, etc. Are performed.

[1], [2], [3],