Assessment of the condition of the fetus. Modern methods of fetal research
Ultrasound Screening
The main method of monitoring the baby's condition is ultrasound. Thanks to its use, it is possible to detect the embryo itself, starting from the earliest dates - from 2-3 weeks. Already during this period, with the help of ultrasound, the fetal heartbeat is determined, which confirms its correct development.
An ultrasound scan is performed several times during pregnancy. At 10-14 weeks, the first screening is performed, aimed at detecting chromosomal abnormalities in the fetus. At the same time, the following are evaluated:
1.thickness of the collar space (TVP); this is the area between the inner surface of the fetal skin and the outer surface of its soft tissues, covering the cervical spine, in which fluid can accumulate; normally, in terms of 11-14 weeks, it is 2-2.8 mm; TVP is a marker of fetal chromosomal abnormalities, primarily Down's syndrome;
2. the presence and length of the nasal bone (NK); normally for a period of 12-13 weeks is 3 mm; her absence is suspicious of Down syndrome.
Together with the first ultrasound screening, maternal serum markers ("double test") are determined: free human chorionic gonadotropin (b-hCG) and pregnancy-associated plasma protein A (PAPP-A), the level of which changes with fetal chromosomal abnormalities: Down's syndrome ( trisomy 21 chromosome), Edwards syndrome (18) and Patau syndrome (13).
The second ultrasound screening is carried out at 20-22 weeks, so that if a genetic pathology is detected, the woman has the opportunity to terminate the pregnancy up to 24 weeks, that is, until the time when the fetus is considered viable. Second trimester biochemical screening ("triple test") is currently canceled due to the large number of false results.
When prolonging pregnancy, the next ultrasound is recommended to be performed at 32-34 weeks and before childbirth. If necessary, the number of studies is increased.
Feto- and placentometry
During an ultrasound, fetometry is performed - measuring the size of the fetus. At the same time, such parameters of the fetus as:
Biparietal size (BPR),
- head circumference (OG),
-abdominal circumference (coolant),
- thigh length (DB),
- the size of the liver and spleen,
- estimated mass (PMP).
With ultrasound, it is possible to assess the size of the placenta, its condition, the degree of maturity and the amount of amniotic fluid, the parameters of which may change with some pathology of the fetus.
Also, ultrasound allows you to determine the muscle tone of the fetus in real time, to identify increased ("boxer posture") or decreased tone (symptom of an "open handle" - unclenched hand and extended fingers), to study the respiratory movements of the fetus (FDP), which are contractions of the respiratory muscles and diaphragm ...
Normally, at 35-40 weeks of gestation, the fetal respiratory rate can reach 50 per minute, combined with periods of apnea (lack of breathing). Changes in fetal respiratory movements at the end of pregnancy, especially of the type of shortness of breath, are considered an unfavorable prognostic sign and require special treatment.
Dopplerometry
Today, ultrasound data makes it possible not only to assess the size of body parts, organs and the fetus itself. With the help of a modern modification of ultrasound - dopplerometry, which studies the blood flow in various vessels, it is possible to assess the composition of the fetal blood non-invasively, that is, without using operational methods for taking the baby's umbilical cord blood.
So, by the speed of blood flow in the middle cerebral artery of the fetus, one can judge the level of its hemoglobin (oxygen carrier), as well as the presence and severity of anemia (decrease in erythrocytes and hemoglobin) and hypoxia (lack of oxygen).
Assessment of the parameters of blood flow in the middle cerebral artery allows to determine the management tactics for multiple pregnancies and hemolytic disease of the fetus. If signs of anemia are detected, an intervention is performed - intrauterine blood transfusion (MIC) to the fetus to replenish the circulating blood volume (up to 32-33 weeks of gestation) or delivery (after 32-33 weeks).
Cardiotocography
To assess the condition of the baby, all pregnant women undergo cardiotocography - registration of the fetal heart rate depending on its activity (movements), uterine contractions and various external factors.
CTG is performed from 32 weeks of gestation. The study is performed with the pregnant woman on her back, on her left side, or sitting in a comfortable position. In this case, the sensor is placed in the area of stable recording of the fetal heart rate. The research is carried out within 50-60 minutes.
Fetal cardiograms are interpreted taking into account 5 indicators of cardiac activity: heart rate (HR), amplitude and frequency of oscillations (oscillations), the presence of accelerations (deceleration of heart rate) and decelerations (acceleration of heart rate).
Each of these parameters is assessed in points (from 0 to 2), the condition of the fetus - by the total amount of points. With 8-10 points, the fetus is considered good, with 6-7 points, it requires intensive therapy, less than 5 - emergency delivery.
CTG has no contraindications and is absolutely safe. Using the method allows you to monitor the condition of the fetus for a long time, if necessary - daily. However, it should be understood that the conclusion of CTG is not a diagnosis, but only represents some information along with the results of other research methods.
Amniocentesis
Often, for the examination of the fetus, invasive (with the introduction into the body) procedures are required, which include amniocentesis - obtaining amniotic fluid through a puncture in the fruit membranes.
The procedure is performed on an outpatient basis in the II and III trimesters under ultrasound guidance. For puncture, the most convenient place is chosen depending on the location of the placenta and small parts of the fetus. For the intervention, a special puncture needle is used, which, after puncturing the anterior abdominal wall, uterus and fruit membranes, enters the amniotic bladder. 10-15 ml of amniotic fluid is taken from it.
In the future, a laboratory study of the obtained waters is carried out. In this case, the following indicators can be determined:
Signs of intrauterine infection;
- fetal blood group;
- the optical density of bilirubin (OPB) - a sign of hemolytic disease of the fetus;
- fetal karyotype (genetic testing of the sample); it is used to diagnose chromosomal abnormalities (Down's syndrome, etc.) and hereditary diseases (cystic fibrosis, etc.);
- the degree of maturity of the lungs according to a special foam test.
Also, through amniocentesis, a number of therapeutic manipulations are performed during pregnancy: the introduction of drugs into the amniotic cavity, treatment of complications of multiple pregnancies.
You should be aware that amniocentesis is performed only if there are certain indications, since complications are possible in the postoperative period. Here are the main ones:
Leakage of water;
-infection;
- premature birth.
Cordocentesis
In some critical situations, a more in-depth examination of the fetus is required - the study of the umbilical cord blood. This is possible due to the use of cordocentesis - puncture (puncture) of the umbilical cord vein.
Cordocentesis is performed if there is a suspicion of chromosomal fetal abnormalities, severe forms of fetal hemolytic disease, fetal anemia with multiple pregnancies, etc. Contraindications to cordocentesis are: the threat of termination of pregnancy and severe disorders of the mother's blood coagulation system.
The study is carried out under ultrasound control. At the first stage, amniocentesis is performed. Then, through the lumen of the first needle, a second needle is inserted into the amniotic cavity, brought to the umbilical cord vein and punctured. Next, a syringe is connected and 2 ml of fetal blood is removed, after which the needles are slowly removed from the uterine cavity.
At the same time, the work of a surgeon can be compared with jewelry, because the size of the umbilical cord vein is extremely small, which leads to the risk of complications (thrombosis of the umbilical vein, the addition of a bacterial infection, fetal death). In the obtained blood sample from the umbilical cord vein, the following indicators are assessed:
Blood type, Rh-affiliation,
-values of hematocrit, hemoglobin, leukocytes, platelets;
- levels of liver enzymes, bilirubin;
- indicators of iron metabolism;
-gas composition of blood;
- acid-alkaline state.
Cordocentesis is performed not only for diagnostic, but also for therapeutic purposes. If, according to the examination, the fetus has anemia (decreased hemoglobin), then the intervention is carried out - intrauterine blood transfusion (MIC) to the fetus to replenish the circulating blood volume, which fully justifies the risk of the intervention. Indeed, without the MIC, the fetus could die.
Modern diagnostic technologies make it possible to identify any abnormality in the development of the fetus from the earliest stages of pregnancy. The main thing is to pass all the necessary examinations in a timely manner and follow the recommendations of specialists.
Always with you,
inflammatory processes in the vagina and cervix, as well as placenta previa.
For amnioscopy, the pregnant woman is placed in a gynecological chair and a vaginal examination is performed to determine the patency of the cervical canal. If necessary, make a careful digital expansion of it. Under aseptic conditions, on the finger or after exposing the neck with mirrors, a tube with a mandrel is inserted into the cervical canal behind the internal pharynx. The diameter of the tube is selected depending on the opening of the neck (12-20 mm). After removing the mandrel and turning on the illuminator, the tube is positioned so that the presenting part of the fetus is visible, from which the light beam is reflected. If a mucous plug interferes with inspection, it is carefully removed using a swab. With a low location of the placenta on the membranes, a vascular pattern is clearly visible. With placenta previa, the entire field of vision has a dark red color, in this case, the study must be stopped immediately.
Amniocentesis- an operation, the purpose of which is to obtain amniotic fluid for biochemical, hormonal, immunological, cytological and genetic studies, allowing to judge the state of the fetus.
Indications to amniocentesis are isoserological incompatibility of the blood of the mother and the fetus, chronic fetal hypoxia (prolonged pregnancy, preeclampsia, extragenital diseases of the mother, etc.), establishing the degree of fetal maturity, antenatal sex diagnostics, the need for karyotyping in case of suspected fetal malformations, microbiological examination. The operation is always performed under ultrasound guidance, choosing the most convenient puncture site depending on the location of the placenta and small parts of the fetus.
^ Depending on the puncture site, there are:
a) transvaginal amniocentesis. Produced through the anterior vaginal fornix, cervical canal or posterior vaginal fornix. The choice of the place of insertion of the puncture needle depends on the location of the placenta. After preliminary sanitation of the vagina, the cervix is fixed with bullet forceps, shifted up or down, depending on the chosen method, and the vaginal wall is punctured at an angle to the uterine wall. When the puncture needle enters the uterine cavity, amniotic fluid begins to emerge from it.
b) transabdominal amniocentesis. After treatment of the anterior abdominal wall with an antiseptic, anesthesia of the skin, subcutaneous tissue and subgaleal space is performed 0.5 % solution of novocaine. A needle can be used to perform the procedure, as for a lumbar puncture. For research, take 10-15 ml of amniotic fluid. Samples contaminated with blood or meconium are considered unsuitable. In pregnant women with Rh sensitization, when it is necessary to study the optical density of bilirubin, a sample of amniotic fluid should be quickly transferred to a dark vessel in order to avoid changes in the properties of bilirubin under the influence of light. The puncture site on the anterior abdominal wall is treated with an antiseptic and an aseptic adhesive is applied.
Complications: premature rupture of amniotic fluid (more often with transcervical access), injury to the vessels of the fetus, injury to the bladder and intestines of the mother, chorioamnionitis, premature rupture of the membranes, premature birth, placental abruption, injury to the fetus and damage to the umbilical cord. However, due to the widespread introduction of ultrasound control of this operation, complications are extremely rare.
Contraindications: almost the only contraindication to it is the threat of termination of pregnancy.
^
In the formation and integration of functional systems necessary for the adaptation of the fetus to the external environment, not only the fetus, but also the mother is involved. During pregnancy, the mother's body adapts to the fetus. A strict sequence of not only the development of organs and systems of the fetus is genetically programmed, but also the processes of adaptation to pregnancy of the maternal organism, which occurs in full accordance with the stages of intrauterine development.
For example, the receipt of oxygen from the outside is provided by the hemodynamic functional system mother-placenta-fetus, which is a subsystem of the general functional system mother-fetus. It develops first in the earliest ontogenesis. In it, fetoplacental and uteroplacental blood circulation is simultaneously formed.
In the placenta, there are two blood flows: 1) the flow of maternal blood, due mainly to the systemic hemodynamics of the mother; 2) the blood flow of the fetus, depending on the reactions of its cardiovascular system. The maternal blood flow is shunted by the vascular bed of the myometrium. At the end of pregnancy, the percentage of blood flowing to the intervillous space varies between 60 and 90. These fluctuations in blood flow depend mainly on the tone of the myometrium. A paravascular network develops around the arteries and veins in the villi, which is considered as a shunt capable of passing blood in conditions when blood flow through the exchangeable part of the placenta is obstructed. Fetoplacental and uteroplacental blood circulation are coupled, the intensity of blood flow is the same. Depending on the changes in the state of activity of the mother and the fetus, each of them redistributes blood in such a way that the oxygenation of the fetus remains within the normal range.
The development of the endocrine functional system of the fetus-placenta-mother is peculiar, which is especially clearly seen in the example of estriol synthesis. The enzyme systems required for estrogen production are distributed between the fetus (its adrenal glands and liver), the placenta, and the mother's adrenal glands. The first step in estrogen biosynthesis during pregnancy (hydroxylation of the cholesterol molecule) occurs in the placenta. The resulting pregnenolone from the placenta enters the fetal adrenal glands, converting them into dehydroepiandrosterone (DEA). DEA enters the placenta with the venous blood, where it undergoes aromatization under the influence of enzyme systems and is converted into estrone and estradiol. After a complex hormonal exchange between the body of the mother and the fetus, they are converted into estriol (the main estrogen of the fetoplacental complex).
^ Methods for determining the functional state of the fetoplacental system at different stages of pregnancy.
1. Evaluation of the growth and development of the fetus by measuring the height of the fundus of the uterus, abdominal circumference, ultrasound biometry of the fetus.
2. Assessment of the state of the fetus by studying its motor activity and cardiac activity.
3. Ultrasound assessment of the state of the placenta.
4. Study of placental circulation, blood flow in the vessels of the umbilical cord and large vessels of the fetus.
5. Determination of the level of hormones and specific proteins of pregnancy in the mother's blood serum.
6. Assessment of the state of metabolism and homeostasis in the body of a pregnant woman.
Placental insufficiency: diagnosis, treatment, prevention.
Classification. There are primary and secondary placental insufficiency.
^ Primary placental insufficiency develops during the formation of the placenta and is most often found in pregnant women with a history of recurrent miscarriage or infertility.
^ Secondary placental insufficiency occurs after the formation of the placenta and is due to exogenous influences, diseases transferred during pregnancy.
The course of both primary and secondary placental insufficiency can be acute and chronic. ^ Acute placental insufficiency occurs due to extensive heart attacks and premature detachment of the normally located placenta.
In development chronigesque placental insufficiency Of primary importance is the gradual deterioration of decidual perfusion as a result of a decrease in the compensatory-adaptive reactions of the placenta in response to the pathological conditions of the maternal organism.
Clinically, it is customary to distinguish between relative and absolute placental insufficiency. ^ Relative deficiency characterized by persistent hyperfunction of the placenta and is compensated. This type of placental insufficiency develops with the threat of termination of pregnancy, moderate manifestations of late gestosis (edema, grade I nephropathy) and, as a rule, responds well to therapy.
^ Absolute (decompensated) placental insufficiency characterized by a breakdown of compensatory-adaptive mechanisms and develops in hypertensive forms of preeclampsia, ultimately leading to a delay in development and fetal death.
^ Etiology and pathogenesis. During physiological pregnancy, the placental vessels are in a state of dilatation and do not respond to contracting impulses. This ensures an even supply of oxygen and nutrients to the fetus. Refractoriness to vasopressors of the vessels of the placenta and the mother's circulatory system as a whole is provided due to the increasing production of endothelial relaxation factors - prostacyclin and nitric oxide. Pathology of placental circulation develops in cases where the invasive ability of the trophoblast is reduced and the process of invasion covers the spiral vessels unevenly. The placental vessels partially retain smooth muscle structures, adrenergic innervation and the ability to respond to vasoactive stimuli. Such areas of the placental vessels become targets for the action of mediators circulating in the bloodstream. Structural changes occurring in the vessels in response to their relaxation and contraction underlie disorders of the placental circulation. The development of placental insufficiency is accompanied by almost all complications of pregnancy: preeclampsia, extragenital pathology, sexually transmitted infections, harmonious reproductive system disorders before pregnancy: insufficiency of the luteal phase of the cycle, anovulation, hyperadrogenism, hyperprolactinemia, etc., systemic diseases.
Risk factors: the influence of natural and socio-economic conditions, stressful situations, heavy physical exertion, the use of alcohol, drugs, smoking, age, constitutional features of the expectant mother, extragenital diseases, peculiarities of the course of this pregnancy (gestosis, polyhydramnios, Rh-conflict).
^ Clinical presentation and diagnosis. The diagnosis of placental insufficiency is established on the basis of anamnesis data, pregnancy course, clinical and laboratory examination. To assess the course of pregnancy, the function of the placenta and the condition of the fetus, the following are performed:
regular obstetric observation;
dynamic ultrasound examination in I, II, III trimesters;
dopplerometry;
study of hemostasis;
determination of estradiol, progesterone, chronic gonadotropin, α-fetoprotein in the blood;
colpocytological examination;
CTG of the fetus;
determination of the height of the fundus of the uterus.
^ Treatment and prevention. The success of preventive measures and treatment for placental insufficiency is determined by the timely diagnosis and therapy of concomitant diseases and complications of pregnancy. With the threat of early termination of pregnancy, due to a low level of estrogen, signs of chorionic detachment, bloody discharge, it is recommended to treat with low doses of estrogen.
1. With a low basal level of chorionic gonadotropin, appropriate drugs (pregnyl, prophasi) are administered up to 12 weeks. pregnancy. To maintain the function of the corpus luteum, progesterone, duphaston, utrotestan (up to 16-20 weeks) are used.
2. Therapeutic and prophylactic measures include diet therapy, vitamins, physiotherapy, sleep normalizing agents.
3. It is advisable to use antioxidants (a-tocopherol acetate), hepatoprotectors, nootropics, adaptogens.
4. The main drugs used to maintain pregnancy after 20 weeks are b-blockers, magnesium sulfate, metacin.
5. Upon receipt of data on infection (exacerbation of pyelonephritis, polyhydramnios, detection of urogenital infection), etiotropic antibiotic therapy and vaginal sanitation are performed. Eubiotics are widely used, acting by the method of competitive displacement of pathogenic and opportunistic flora.
6. In the complex therapy of late gestosis necessarily include funds that improve uteroplacental blood flow (glucose-novocaine mixture, rheopolyglucin, trental), conduct sessions of abdominal decompression, hyperbaric oxygenation.
7. In the presence of antiphospholipid syndrome, antiplatelet agents (aspirin, courantil), low molecular weight heparins (fraxiparin), immunoglobulins are used. A high titer of antiphospholipids can be reduced by a course of plasmapheresis.
^ Blood circulation of the fetus and newborn.
Blood enriched in the placenta with oxygen and nutrients enters the body through the umbilical cord vein. Having penetrated through the umbilical ring into the abdominal cavity of the fetus, the umbilical cord vein approaches the liver, gives it branches, then goes to the inferior vena cava, into which arterial blood is poured. In the inferior vena cava, arterial blood is mixed with venous blood coming from the lower half of the body and internal organs of the fetus. The section of the umbilical cord vein from the umbilical ring to the inferior vena cava is called the venous (arantia) duct.
Blood from the inferior vena cava enters the right atrium, where venous blood from the superior vena cava is also infused. Between the place of confluence of the inferior and superior vena cava is a valve (Eustachian), which prevents mixing of blood coming from the superior and inferior vena cava. The flap directs the blood flow of the inferior vena cava from the right atrium to the left through the foramen ovale located between both atria. From the left atrium, blood enters the left ventricle, from the ventricle - to the aorta. From the ascending aorta, blood, containing a relatively large amount of oxygen, enters the vessels supplying blood to the head and upper body.
Venous blood entering the right atrium is sent from the superior vena cava to the right ventricle, and from it to the pulmonary arteries. From the pulmonary arteries, only a small portion of the blood flows to the non-functioning lungs. The bulk of blood from the pulmonary arteries enters through the arterial (botall) duct into the descending aorta. The descending aorta, which contains a significant amount of venous blood, supplies blood to the lower half of the trunk and lower extremities. Fetal blood, poor in oxygen, enters the arteries of the umbilical cord (branches of the iliac arteries) and through them into the placenta. In the placenta, the blood receives oxygen and nutrients, is freed from carbon dioxide and metabolic products and returns to the fetus through the umbilical cord vein.
Purely arterial blood in the fetus is contained only in the vein of the umbilical cord, in the ductus venosus and branches leading to the liver. In the inferior vena cava and the ascending aorta, the blood is mixed, but contains more oxygen than the blood in the descending aorta. As a result of these features of blood circulation, the liver and the upper part of the body of the fetus are supplied with arterial blood better than the lower half of the body. As a result, the liver of the fetus reaches a large size, the head and upper body in the first half of pregnancy develop faster than the lower body. As the fetus develops, there is some narrowing of the foramen ovale and a decrease in the valve. In this regard, arterial blood is more evenly distributed throughout the fetal body and the lag in the development of the lower half of the body is leveled.
Immediately after birth, the fetus takes its first breath, in which the lungs expand. From this moment, pulmonary respiration begins and extrauterine type of blood circulation. Blood from the pulmonary artery now enters the lungs, the ductus arteriosus collapses, and the lower venous duct becomes empty. The blood of a newborn, enriched in oxygen in the lungs, flows through the pulmonary veins into the left atrium, then into the left ventricle and aorta. The foramen ovale between the atria is closed. Thus, an extrauterine type of blood circulation is established in a newborn.
The fetal heartbeat during auscultation through the abdominal wall begins to be heard from the beginning of the second half of pregnancy, sometimes from 18-20 weeks. Its frequency averages 120-140 beats per minute and can vary within wide limits. It depends on many physiological (fetal movement, the effect on the mother of heat, cold, muscle load, etc.) and pathological (lack of oxygen and nutrients, intoxication, etc.) factors. The rhythm, frequency, and character of heart sounds change especially significantly during hypoxia. With the help of phonocardiography, fetal heart sounds can be recorded from 16-17 weeks of pregnancy, and ultrasound scanning makes it possible to establish the presence of cardiac activity from 8-10 weeks of intrauterine development.
^ Ultrasound examination during pregnancy. Indications.
When performing ultrasound in obstetric practice, both transabdominal and transvaginal scanning can be used. The choice of the type of transducer depends on the gestational age and the purpose of the study.
During pregnancy, it is advisable to conduct a three-fold screening ultrasound examination:
1) at the first visit of a woman about a delay in menstruation in order to diagnose pregnancy, localize the ovum, identify possible deviations in its development, as well as the abilities of the anatomical structure of the uterus. When conducting ultrasound examination in the early stages of pregnancy, special attention should be paid to the anatomical features of the developing embryo, since markers of chromosomal pathology in the fetus (for example, expansion of the neck zone) and pronounced malformations (anencephaly , kidney agenesis, etc.);
2) at a gestational age of 16-18 weeks. in order to identify possible anomalies in the development of the fetus for the timely use of additional methods of prenatal diagnosis or raising the issue of termination of pregnancy;
3) with a period of 32-35 weeks. in order to determine the state, localization of the placenta and the rate of development of the fetus, their compliance with the gestational age, the position of the fetus before childbirth, its estimated mass.
With an ultrasound examination, the diagnosis of uterine pregnancy is possible from 2-3 weeks, while in the thickness of the endometrium, the ovum is visualized in the form of a rounded formation of low echogenicity with an inner diameter of 0.3-0.5 cm. In the first trimester the rate of weekly growth of the average size of the ovum is approximately 0.7 cm, and by 10 weeks. it fills the entire uterine cavity. By 7 weeks. pregnancy in most pregnant women, when examining in the cavity of the ovum, it is possible to identify the embryo as a separate formation of increased echogenicity 1 cm long.At this time, the embryo can already visualize the heart - an area with rhythmic fluctuations of small amplitude and weak motor activity. When performing biometrics in the first trimester, the determination of the average inner diameter of the ovum and the coccygeal-parietal size of the embryo, the values of which are strongly correlated with the gestational age, are of primary importance for establishing the gestational age. The most informative method of ultrasound examination in early pregnancy is transvaginal scanning; A transabdominal scan is only used when the bladder is full to create an “acoustic window”.
Ultrasound in II and III trimesters allows you to obtain important information about the structure of almost all organs and systems of the fetus, the amount of amniotic fluid, the development and localization of the placenta and diagnose violations of their anatomical structure.
Of greatest practical importance in conducting a screening study from the second trimester, in addition to a visual assessment of the anatomical structure of fetal organs, is the definition of the main fetometric indicators:
1) with a cross-section of the fetal head in the area of the best visualization of the median structures of the brain (M-echo), the biparietal size of the frontal-occipital size is determined, on the basis of which it is possible to calculate the circumference of the fetal head;
2) with a cross section of the abdomen perpendicular to the fetal spine at the level of the intrahepatic segment of the umbilical vein, on which the abdominal section has the correct rounded shape, the anteroposterior and transverse abdominal diameters are determined, on the basis of which the average abdominal diameter and its circumference can be calculated;
3) with free scanning in the area of the pelvic end of the fetus, a clear longitudinal section of the fetal femur is achieved, followed by determination of its length. Based on the fetometric indicators obtained, it is possible to calculate the estimated weight of the fetus, while the error when changing the generally accepted calculation formulas usually does not exceed 200-300 g.
For a qualitative assessment of the amount of amniotic fluid, the measurement of "pockets" free from parts of the fetus and umbilical cord loops is used. If the largest of them is less than 1 cm in size in two mutually perpendicular planes, we can talk about low water, and if its vertical size is more than 8 cm - about high water.
Currently, tables of organometric parameters of the fetus, depending on the gestational age, have been developed for almost all organs and bone formations, which should be used if the slightest suspicion of a deviation in its development arises.
With the development and improvement of ultrasound diagnostic equipment, it became possible to non-invasively measure the blood flow velocity in the vessels of the fetus, the umbilical cord and in the uterine arteries.
The use of ultrasound in the study of the placenta allows you to accurately establish its localization, thickness, structure. With real-time scanning, especially with transvaginal examination, a clear image of the chorion is possible from 5-6 weeks of gestation.
An important indicator of the condition of the placenta is its thickness, which is characterized by a typical growth curve as pregnancy progresses. By 36-37 weeks, the growth of the placenta stops, and in the future, during the physiological course of pregnancy, either decreases or remains at the same level, amounting to 3-3.6 cm.
^ Modern methods for assessing the condition of the fetus.
Determination of α-fetoprotein.
It is carried out as part of screening programs to identify pregnant women at a higher risk of congenital and inherited fetal diseases and complicated pregnancy. The study is carried out in the period from the 15th to the 18th week of pregnancy. The average figures for the level of alpha-fetoprotein in the serum of pregnant women are at a period of 15 weeks. - 26 ng / ml, 16 weeks - 31 ng / ml, 17 weeks - 40 ng / ml, 18 weeks - 44 ng / ml. The level of alpha-fetoprotein in the mother's blood increases with some fetal malformations (neural tube defects, pathology of the urinary system, gastrointestinal tract and anterior abdominal wall) and pathological pregnancy (threat of termination, immunoconflict pregnancy, etc.). The level of alpha-fetoprotein is also increased in multiple pregnancies. A decrease in the level of this protein can be observed in fetal Down's disease.
In case of deviations in the level of alpha-fetoprotein from normal values, further examination of the pregnant woman is indicated in a specialized perinatal medical center.
Fetal electrocardiography and phonography.
Electrocardiography: direct and indirect.
a) Direct electrocardiography produced directly from the head of the fetus during childbirth when the cervix is opened by 3 cm or more. Atrial P wave, ventricular QRS complex, T wave are recorded. It is rarely performed.
b) Indirect electrocardiography carried out by placing electrodes on the anterior abdominal wall of the pregnant woman (the neutral electrode is located on the thigh). This method is used mainly in the antenatal period. Normally, the ventricular QRS complex is clearly visible on the ECG, sometimes the P wave. Maternal complexes are easy to differentiate with simultaneous registration of the mother's ECG. The fetal ECG can be recorded from the 11th - 12th week of pregnancy, but in 100% of cases it can be recorded only by the end of the third trimester. As a rule, indirect electrocardiography is used after 32 weeks of pregnancy.
^ Phonocardiogram (PCG) the fetus is recorded when the microphone is placed at the point where the stethoscope can best listen to its heart tones. It is usually represented by two groups of oscillations, which reflect I and II heart sounds. Sometimes III and IV tones are recorded. Fluctuations in the duration and amplitude of heart sounds are very variable in the third trimester of pregnancy and are on average: I tone - 0.09 s (from 0.06 to 0.13 s), II tone - 0.07 s (from 0.05 to 0 , 09 s).
With the simultaneous registration of the ECG and PCG of the fetus, it is possible to calculate the duration of the phases of the cardiac cycle: phases of asynchronous contraction, mechanical systole, total systole, diastole. The phase of asynchronous contraction is detected between the beginning of the Q wave and I tone, its duration is 0.02-0.05 s. Mechanical systole is the distance between the onset of I and II sounds and lasts from 0.15 to 0.22 s. General systole includes mechanical systole and an asynchronous contraction phase; it is 0.17-0.26 s. Diastole, calculated as the distance between the beginning of II and I tone, is 0.15-0.25 s. It is also important to calculate the ratio of the duration of total systole to the duration of diastole, which averaged 1.23 at the end of an uncomplicated pregnancy.
^ Determination of the biophysical profile of the fetus.
^
Test method:
a) a non-stress test is performed (see question non-stress test)
b) the fetus is observed using ultrasound in real time for 30 minutes in order to identify the criteria (see table). It is best to do the research after eating.
Interpretation of the test:
a) normal test - the number of points 10-8 (out of 10 possible)
B) suspicious - 6-7 points, i.e. chronic asphyxia is possible and the test must be repeated within 24 hours
| Parameter | 2 points | 1 point | 0 points |
| Non-stress test | 5 accelerations or more with an amplitude of at least 15 beats / min. duration of at least 15 s, associated with the movement of the fetus, for 20 min of observation | 2-4 accelerations with an amplitude of at least 15 beats / min. duration of at least 15 s, associated with the movement of the fetus. for 20 minutes of observation | 1 acceleration or lack thereof in 20 min of observation |
| Respiratory movements of the fetus | At least 1 episode of DDP lasting 60 seconds or more in 30 minutes | At least 1 episode of DDP lasting from 30 to 60 seconds in 30 minutes | Duration |
| Fetal motor activity | At least 3 generalized movements in 30 minutes | 1 or 2 generalized movements in 30 min | Lack of generalized movements |
| Fetal tone | 1 episode or more of extension with return to flexion position of the spine and limbs in 30 min | At least 1 episode of extension with return to flexion position of either the limbs or the spine in 30 minutes | Extremities in an extension position |
| Amniotic fluid volume | Waters are clearly defined in the uterus, the vertical diameter of the free area of water is 2 cm or more | The vertical diameter of the free area of water is more than 1 cm, but less than 2 cm | Close arrangement of small parts of the fruit. the vertical diameter of the free area of water is less than 1 cm |
D) any number of points less than 10 with the presence of oligohydramnios is an indication for immediate delivery (if oligohydramnios is not associated with rupture of the membranes).
^ Biophysical Profile Assessment Criteria
The advantages of the test:
A) can be performed on an outpatient basis
B) low false-positive rate (compared to non-stress test)
C) no contraindications
D) can be used at the beginning of the third trimester of pregnancy
Disadvantages of the test:
A) requires the skill of an ultrasound specialist
B) requires more time (45-90 minutes).
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When considering administrative and budgetary issues of the functioning of international organizations, Russia is consistently striving to increase the efficiency of the UN Secretariat (as well as the secretariats of other international organizations) in implementing decisions of the member states, strengthening accountability and transparency in its activities, and strengthening the responsibility of secretariat officials for decisions and results. work, as well as ensuring the efficiency and transparency of procurement and fair international competition in the United Nations market.
We believe that the UN platform provides all the opportunities for developing a broad dialogue in this area with the participation of representatives of states and civil society. We are ready to take the most active part in it.
Russia is a member of the Group of Friends of the Alliance of Civilizations (AC) and supports the activities of the High Representative of the UN Secretary General for the Alliance of Civilizations J. Sampaio. We are confident that the AC can become a real structure for strengthening cooperation in this area of modern international relations. This, in particular, is evidenced by the First Alliance Forum held in Madrid in January 2008, which was attended by delegations from more than 80 states, including Russia, and over 300 representatives of NGOs, religious structures, business circles and the media.
In general terms, we understand the urgent need to adapt the UN and all its bodies to the changing conditions in the world and firmly advocate the reform of international institutions while strengthening the central role of the world Organization. This position remains unchanged for us. We have always proceeded and continue to proceed from the premise that over the last century humanity has not invented anything more effective than the UN to maintain the global security regime.
Ultrasound scanning is highly informative harmless
research method and allows dynamic monitoring of the state
Monitoring the development of pregnancy is possible from the earliest possible date. As early as 3 weeks
pregnancy, a fetal egg with a diameter of 5-6 mm is visualized in the uterine cavity. B 4-5
weeks, it is possible to identify the embryo in the form of an echo-positive strip 6-7 mm in size.
The head of the embryo is identified from 8-9 weeks of age as a separate anatomical
rounded formations with a diameter of 10-11 mm. Embryo growth occurs
uneven. The highest growth rates are noted at the end of the first trimester. Most
an accurate indicator of the gestational age in the first trimester is the size of the coccyx
parietal size.
Evaluation of the vital activity of the embryo in the early stages is based on the registration of its
cardiac activity and physical activity. Using an intrauterine device
operating mode allows you to register cardiac activity from 4-5
weeks of pregnancy. The heart rate increases from 150-160 per minute per
5-6 weeks to 175-185 in 1 minute at 7-8 weeks with a subsequent decrease to 150 in 1
minute to 12 weeks.
Motor activity is detected from 7-8 weeks of pregnancy. Lack of cervical
activity and physical activity indicates the death of the embryo.
The most important place is occupied by ultrasound examination in case of complicated course
pregnancy, since other additional research methods are laborious and not
always provide sufficient information about the development of the embryo.
Diagnosis of undeveloped pregnancy is possible when an empty fetal hypoxia of the fetus and pathology of the umbilical cord are detected.
3. Cardiotocography of the fetus.
Fetal cardiotocographic examination is one of the leading methods of assessment
condition of the fetus. Modern heart monitors are based on the Doppler principle, their
use allows you to register changes in the intervals between individual
fetal heart cycles that translate into frequency changes
heartbeats and are reflected in the light, sound, digital and
graphic image. The devices are also equipped with sensors that allow
register simultaneously the contractile activity of the uterus and fetal movement.
Fetal cardiac activity is assessed in points. The amount of points indicates the presence
or no signs of fetal cardiac abnormalities: 8-10 points
is regarded as normal, 5-7 points, as a pre-pathological condition indicating
the need for further careful monitoring of the fetus; 4 points or less - as
pathological.
4. Biophysical profile of the fetus (BFP).
The biophysical profile assessment includes 6 parameters:
a) non-stress test (NST)
b) respiratory movements of the fetus (FDP)
c) physical activity (YES)
d) fetal tone (T)
e) the volume of amniotic fluid (AMI)
f) the degree of maturity of the placenta (FFP)
The maximum score is 10-12 points. The non-stress test is assessed when
cardiomonitoring study. Its essence lies in the study of the reaction
cardiovascular system of the fetus in response to movement. Normal fetal movement
accompanied by an acceleration of the heart rate. In the absence of a reaction
fetal cardiac activity in response to movement the test is considered negative, which
indicates the tension and exhaustion of the fetal compassionate reactions.
The rest of the FFP parameters are determined by ultrasound scanning.
Respiratory movements of the fetus become regular from 32-33 weeks of pregnancy and
occurs with a frequency of 40-70 per minute. In case of complicated pregnancy
there is an increase in the number of respiratory movements up to 100-150 per minute, or
their decrease to 10-15 per minute is noted, with the appearance of individual convulsive
movements, which is a sign of chronic intrauterine hypoxia.
An indicator of the state of the fetus is its physical activity and tone. Healthy
pregnant women, fetal movements reach a maximum by the 32nd week of pregnancy,
after which their number decreases by the 40th week. Fetal tonks are characterized by
extensor-flexion movements of the limbs and the spinal column with
return to the original flexion position. If the limbs are straightened or movement
the fetus does not end with a return to the flexion position, this indicates
progressive hypoxia. An indicator of good fetal condition is at least 3
active fetal movements in 30 minutes.
The volume of amniotic fluid, unlike other parameters, does not reflect the functional
the state of the central nervous system of the intrauterine fetus, however, this indicator is directly related to
the outcome of pregnancy. A decrease in the amount of amniotic fluid indicates
pathological outcome of pregnancy.
Ultrasound placentography allows you to determine the correspondence to the degree of maturity
placenta during pregnancy. With an uncomplicated course of pregnancy, 0 degree of maturity of the placenta is noted at a gestational age of 27-30 weeks, 1 degree - at 30-32
weeks, II degree - at 34-36 weeks, III degree - at 38 weeks. With complications
pregnancy or extragenital pathology of the mother is observed premature
maturation and aging of the placenta.
5. Amnioscopy.
To study the state of amniotic fluid and the fetus during pregnancy, use
amnioscopy - transcervical examination of the lower pole of the fetal bladder. At
in the uncomplicated course of pregnancy, a sufficient amount of light is released,
transparent, opalescent amniotic fluid with the presence of a white cheese-like lubricant.
Insufficient amount of water, detection of meconium and their greenish color
indicate fetal hypoxia and prolonged pregnancy.
6. Amniocentesis.
In order to obtain amniotic fluid for research, a puncture is performed
amniotic cavity - amniocentesis. For this, several methods of sampling are used.
amniotic fluid: transabdominal, transvaginal, transcervical.
Amniocentesis is performed starting from the 16th week of pregnancy. It is used to assess
maturity of the lungs of the fetus, latent intrauterine infection with suspected
congenital malformations of the fetus, hemolytic disease, prolongation
pregnancy, chronic fetal hypoxia.
With the help of amniocentesis, the biochemical and bacteriological composition is studied,
acid-base state of amniotic fluid, and also diagnose
genetic diseases.
In diseases associated with the X chromosome, the sex of the fetus is determined.
make a cytological study of native cells (determination of X- and Y-
chromatin) or put a culture of cells of the amniotic fluid and determine the karyotype.
When establishing the male sex of the fetus, termination of pregnancy is indicated in connection with
high risk of having a sick boy (50%).
Prenatal diagnosis of open malformations of the central nervous system is carried out using
determination of the content of alpha-fetoprotein in the serum of the mother and amniotic
liquid by radioimmunoassay. Increase in alpha-fetoprotein over 200
ng / ml in serum and 10,000 ng / ml in amniotic fluid indicates
malformation in the fetus.
To diagnose hereditary pathology in the first trimester of pregnancy, use
transcervical chorionic biopsy method. Chorion can be used to
prenatal diagnosis of fetal sex, determination of karyotin and detection of chromosomal
pathology.
7. Fetoscopy - direct examination of the fetus with a special fiberoptic
an endoscope inserted into the amniotic cavity through the abdominal wall and uterus. Method
allows you to examine individual parts of the fetus, placenta, umbilical cord, find some
fetal malformations, take a fetal skin biopsy, or obtain a blood sample from
umbilical cord vessels for the diagnosis of hemophilia or hemoglobinopathies.
8. The acid-base state of the fetal blood reflects the severity of metabolic changes during hypoxia. Normally, the pH is 7.24 and above. PH shift from 7.24
up to 7.2 is regarded as subcompensated acidosis. pH below 7.2 indicates the presence of
decompensated acidosis. The extreme criterion for the viability of the fetus is
blood pH = 6.7.
9. Hormonal research methods.
In assessing the hormonal status of a woman, it should be borne in mind that in the early stages
pregnancy increases the function of all endocrine glands. Already in
preimplantation period at the blastocyst stage, germ cells secrete
progesterone, extradiol and chorionic gonadotropin, which are of great importance for
implantation of the ovum. In the process of fetal organogenesis, hormonal function
the placenta increases and during the entire pregnancy it secretes a large amount
hormones.
Depending on the content of placental hormones (placental lactogen and
progesterone) can be judged on the function of the placenta, while the change in fetal
hormones (estradiol, estriol) to a greater extent reflect the condition of the fetus.
In the last week before childbirth, the excretion of estrogen in the urine is 23-24 mg / day.
In the presence of fetal hypoxia, the level of estrogen with daily urine decreases to 10
mg / day, and a decrease to 5 mg / day indicates the need for urgent
delivery.
A sharp decrease in estrogen (less than 2 mg / day) is observed with anencephaly, pathology
fetal adrenal glands, Down syndrome, intrauterine infection.
The condition of the fetus can be judged by the content in the blood of some pregnant women.
enzymes produced by placental tissue. Particular attention among them is given to
thermostable alkaline phosphatase, which increases with fetal hypoxia
In the physiological course of pregnancy, the condition of the fetus is assessed on the basis of:
The results of comparing the size of the uterus and the fetus with the gestational age;
Auscultation of fetal heart sounds at each visit to a pregnant antenatal clinic:
Motor activity of the fetus;
The results of an ultrasound scan, which is carried out at a gestational age of 18-22 weeks, 32-33 weeks and before childbirth (to identify the correspondence of the biophysical profile of the fetus and the degree of maturity of the placenta to the gestational age).
In case of a complicated course of pregnancy, an assessment of the condition of the fetus is included in the complex of inpatient examination of a pregnant woman, aimed at diagnosing her pathology, fetal hypoxia and determining the degree of its severity.
To diagnose fetal hypoxia, you need:
Assessment of fetal cardiac activity:
Assessment of fetal motor activity;
Amnioscopy;
Ultrasound of the fetus and placenta.
Fetal cardiac activity is assessed based on the results of auscultation of fetal heart sounds and cardiotocography (CTG). Auscultation of fetal heart sounds is performed at each examination of a pregnant woman, in the first stage of labor - every 15-30 minutes and outside the contraction, in the second stage of labor - after each contraction. The frequency, rhythm and sonority of the fetal heart sounds are assessed. Tachy or bradycardia, arrhythmia, deaf or muffled heartbeat of the fetus are clinical signs of hypoxia.
Ante- and intrapartum cardiotocography makes it possible to assess the fetal heart rate against the background of uterine contractile activity and fetal motor activity. Changes in basal rate, heart rate variability, acceleration and deceleration reflect the condition of the fetus and may be signs of hypoxia.
Fetal motor activity is assessed by counting the number of fetal movements in 30 minutes in the morning and in the evening. Normally, 5 or more fetal movements are recorded in 30 minutes. By the evening, in healthy pregnant women, the motor activity of the fetus increases. With the onset of fetal hypoxia, there is an increase and increase in movements, with progressive hypoxia - weakening and decreasing, followed by cessation of fetal movements. With chronic fetal hypoxia, there is an excessive increase or a sharp decrease in the difference between the number of movements in the morning and the number of movements in the evening.
The reaction of the fetal heartbeat to its motor activity can be objectively recorded with CTG (myocardial reflex).
Amnioscopy (transcervical examination of the lower pole of the fetal bladder) is performed using an amnioscope in the absence of contraindications (placenta previa, colpitis, endocervicitis) but during pregnancy (after 37 weeks) and in the first stage of labor. Normally, there is a sufficient amount of light, clear amniotic fluid, with fetal hypoxia - a small amount of greenish water and lumps of meconium.
Ultrasound examination reveals fetal growth retardation syndrome, placental insufficiency, on the basis of which chronic intrauterine fetal hypoxia can be established.
To clarify the severity of fetal hypoxia, it is necessary to use:
CTG with functional (stress) tests;
Doppler ultrasound;
Determination of the biophysical profile of the fetus, ultrasound placentography;
Amniocentesis;
Biochemical studies of placental enzymes and indicators of fetal acid-base balance;
Studies of hormone levels.
CTG with functional (stress) tests is performed in order to timely identify the compensatory capabilities of the fetus. It is possible to carry out tests with holding the breath on inhalation and exhalation, with physical exertion (step test), thermal tests and the identification of the fetal response to ultrasound. The change in the CTG curve against the background of functional (non-stress) tests allows diagnosing fetal hypoxia and its severity. The oxytocin stress test is rarely used due to possible complications for the mother and fetus.
Ultrasound with Doppler ultrasound makes it possible to examine the blood flow in the aorta and umbilical cord of the fetus and in the uterine arteries, obtaining curves of blood flow velocities on the monitor screen. Normally, in the third trimester of pregnancy, there is a gradual increase in volumetric blood flow due to a decrease in peripheral vascular resistance. When fetoplacental circulation is impaired, diastolic blood flow in the umbilical artery and the fetal aorta decreases. Decompensated placental insufficiency has zero and negative diastolic blood flow.
The biophysical profile of the fetus is a cumulative score in points of five parameters: the results of a non-stress test according to CTG data and four indicators of fetal ultrasound. Respiratory movements of the fetus, the motor activity and tone of the fetus, the volume of amniotic fluid, taking into account the degree of "maturity" of the placenta, are assessed. The score indicates the severity of fetal hypoxia.
Ultrasound placentography involves determining the location, size and structure of the placenta. In the normal course of pregnancy, the placenta "matures" and its thickness and area progressively increase by the time of delivery. With placental insufficiency, there is a thinning or thickening of the placenta, an increase or decrease in its area, as well as premature maturation and pathological changes in its structure (cysts, calcification, heart attacks and hemorrhages).
Amniocentesis - the study of amniotic fluid obtained by transabdominal (less often - transcervical) puncture of the amniotic cavity under ultrasound control, allows you to conduct a cytological and biochemical study of fetal cells, determine its gender, chromosomal pathology, metabolic diseases, malformations (in the period of pregnancy 16-18 weeks ).
During pregnancy more than 34 weeks, it is determined:
PH, pCO2, pO2, the content of electrolytes, urea, protein in the amniotic fluid (to diagnose the severity of fetal hypoxia;
The level of hormones (placental lactogen, estriol), enzymes (alkaline phosphatase, β-glucuronidase, hyaluronidase, etc.) (to exclude placental insufficiency and fetal malnutrition);
Optical density of bilirubin, fetal blood group, titer of Rh or group antibodies (to diagnose the severity of fetal hemolytic disease);
Cytological and biochemical (creatinine, phospholipids) indicators (to assess the degree of maturity of the fetus).
Biochemical studies of the level of specific enzymes (oxytocinase and thermostable alkaline phosphatase) of the placenta in the dynamics of the II and III trimesters of pregnancy make it possible to identify the functional state of the placenta.
The study of indicators of the acid-base state (CBS) of the fetus (pH, pCO2 and pO2) is carried out by cordocentesis (puncture of the umbilical cord of the fetus during amniocentesis) during pregnancy or puncture of the presenting part of the fetus during childbirth (Zaling's test). For research, you can also use amniotic fluid. Indicators of CBS in comparison with the results of clinical and instrumental studies (CTG, ultrasound) allow to objectively establish the severity of hypoxia.
Determination of the level of hormones (progesterone, placental lactogen, estrogens) formed in the placenta and organs of the fetus is carried out in the II and III trimester of pregnancy. Normally, the content of all hormones is constantly increasing towards the end of pregnancy. With placental insufficiency, there is a decrease in the level of progesterone and placental lactogen. An indicator of fetal suffering is a decrease in the amount of estriol (produced mainly in the fetus). In chronic placental insufficiency with impaired fetal trophism, a decrease in the concentration of all hormones is revealed.
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The widespread introduction into clinical practice of various methods for assessing the state of the fetus contributes to a significant decrease in perinatal mortality, which is one of the main indicators of the level of development of medical care. Diagnostics is carried out in two directions: 1 - assessment of the features of the anatomical development of the fetus, 2 - the study of its functional state.
Clinical, biochemical and biophysical research methods are used to assess the condition of the fetus during pregnancy and childbirth.
To clinical diagnostic methods relate:
Auscultation,
Determination of the frequency of movement of the fetus,
Determination of the rate of growth of the uterus,
· Determination of the nature of the staining of the amniotic fluid (with amnioscopy, amniocentesis, amniotic fluid outflow).
In daily practice, the obstetrician is widely used auscultation with a stethoscope , the rhythm and heart rate, clarity of heart sounds are assessed. The normal fetal heart rate is 120 to 160 beats per minute. However, auscultation of the fetal heart rate is not always important for assessing the condition of the fetus or for diagnosing its hypoxia. It allows you to identify only gross changes in the heart rate (HR) - tachycardia, bradycardia and severe arrhythmia, which occur more often with acute hypoxia. In chronic hypoxia, in most cases, it is not possible to detect changes in cardiac activity by auscultation. Fetal heart rate auscultation is of great value in determining fetal health when used as a test to assess fetal reactivity. For this purpose, the fetal heartbeat is listened to before and after its movements. An increased fetal heart rate in response to movement is a clear indicator of good fetal health. The absence of a heart rate response or the appearance of only a slight increase in heart rate may indicate fetal hypoxia and requires additional research methods.
An indicator of the condition of the fetus is its physical activity , which in healthy pregnant women reaches a maximum by 32 weeks, after which the number of fetal movements decreases. The appearance of fetal movements (FF) indicates its good condition. If the mother feels DP without their decrease or decrease in activity, then the fetus is healthy and there is no threat to its condition. Conversely, if the mother notes a certain decrease in LTP, then he may be in danger. At the initial stages of intrauterine fetal hypoxia, the restless behavior of the fetus is observed, which is expressed in the increase and increase in its activity. With progressive hypoxia, there is a weakening and cessation of movements.
To assess the motor activity of the fetus, special forms are offered in which a pregnant woman marks each DP from 9:00 to 21:00, that is, 12 hours in advance . Number of DP more than 10 indicates a satisfactory condition of the fetus. If a woman notes less than 10 movements, especially two days in a row, then this condition is regarded as threatening the fetus. Consequently, the obstetrician receives information about the intrauterine state of the fetus from the pregnant woman herself. The registration methodology does not deprive women of their normal daily activities. If negative results are obtained, the doctor should send the pregnant woman to a hospital for examination.
In stationary conditions, in addition to additional research methods, it is possible to use the second method for registering DP to assess its intrauterine state. Pregnant DP is recorded lying on its side for 30 minutes. four times a day (9:00, 12:00, 16:00 and 20:00) and entered into special cards. When evaluating the results, it is important to pay attention not only to a certain number of movements (if the fetus is in a satisfactory condition, it should be not less than 4 in 2 hours), but also on the change in their number over the course of several days. The suffering of the fetus is indicated by the complete disappearance of physical activity or a decrease in the number of DPs by 50% per day. If in the following days DP returns to the previous level, then there is no danger to the fetus at the moment.
Of particular value in the diagnosis of fetal hypoxia is the combined registration of its cardiac activity and motor activity.
A significant amount of information about the condition of the fetus can be obtained by measuring the height of the fundus of the uterus. Measurement data is commonly used between 20 and 36 weeks pregnancy. To determine the rate of growth and development of the fetus, it is necessary in dynamics (every 2 weeks) measure the height of the fundus of the uterus above the pubic articulation and the circumference of the abdomen. Comparison of the sizes obtained with the gestational age allows us to identify a lag in the growth of the fetus. Lagging behind the height of the fundus of the uterus on 2 cm and more compared to the norm or the absence of its growth within 2-3 weeks . with dynamic monitoring of a pregnant woman indicates fetal growth retardation , which requires further evaluation. There are many factors that make it difficult to assess the growth of the fetus (violation of the measurement method, violations of fat metabolism in the mother, excess or reduced amount of amniotic fluid, multiple pregnancies, abnormal position and presentation of the fetus). However, these measurements of the standing height of the uterine fundus remain a good clinical indicator of normal, accelerated or reduced fetal growth.
Amniotic fluid staining during pregnancy can be detected by amnioscopy or amniocentesis, as well as with premature rupture of the membranes.
Amnioscopy- transcervical examination of the lower pole of the fetal bladder. Availability impurities of meconium indicates chronic fetal hypoxia or the former acute short-term, and the fetus, in the absence of new disturbances in its oxygen supply, can be born without asphyxia. The presence of a small admixture of meconium in the amniotic fluid (yellow or greenish color) in premature pregnancy is not an absolute sign of fetal hypoxia. If meconium in the amniotic fluid is found in large quantities (dark green or black), especially in high-risk pregnant women (late gestosis, Rh isoimmunization, chorioamnionitis, etc.), then this is regarded as a threatening condition of the fetus. Turbid staining amniotic fluid indicates a post-term pregnancy, yellow - about GBP or rhesus incompatibility.
Biochemical methods for diagnosing the condition of the fetus:
· Study of the hormonal profile: chorionic gonadotropin, placental lactogen, estrogens (estriol), progesterone, prolactin, thyroid hormones, corticosteroids;
· Determination of the degree of fetal maturity on the basis of a cytological study of amniotic fluid and the concentration of phospholipids (lycetin and sphingomyelin) in amniotic fluid obtained by amniocentesis;
· Examination of fetal blood obtained by intrauterine puncture - cordocentesis;
· Chorionic villus sampling for fetal karyotyping and determination of chromosomal and gene abnormalities.
To assess the condition of the fetus during pregnancy, they also examine hormonal activity of the fetoplacental system , which to a certain extent depends on the physiological activity of the fetus and to a large extent on the functional activity of the placenta. Among biochemical methods studies have found the most widespread application in practice to determine the concentration of estriol and placental lactogen in the mother's body.
In non-pregnant estriol is the main metabolite of the main estrogen - estradiol. During pregnancy, the fetus and placenta are responsible for most of the production of estriol. The average daily amount of hormone excreted in the urine is 30-40mg... Highlighting less than 12 mg / day indicates a decrease in the activity of the fetoplacental complex. Decrease in estriol content up to 5 mg / day indicates the suffering of the fetus. Decrease in estriol excretion below 5 mg / day threatens the life of the fetus. Since the level of estriol in the mother's body is influenced by many factors (the state of liver and kidney function, the difficulty of collecting daily urine, the intake of medicinal substances, a wide range of research results, etc.), the information obtained when determining the level of estriol is valuable if it coincides with other clinical and biophysical parameters. It is generally accepted that estriol levels reliably reflect the state of the fetus in case of pregnancy complicated by late gestosis, fetal growth retardation, maternal diabetes mellitus, that is, in the group of pregnant women with a high risk of fetal hypoxia.
Placental lactogen (PL) synthesized by the placenta and can be determined in maternal serum. The concentration of PL in the mother's blood is in direct proportion to the mass of the functioning placenta. Consequently, in the normal course of pregnancy, serum PL values increase as the placenta grows. In the presence of a pathologically small placenta, PL levels in maternal blood are low. Determination of PL can play a significant role in assessing the condition of the fetus in women who have a fibrous placenta with infarctions of small sizes, especially when pregnancy is complicated by late gestosis or in the presence of intrauterine fetal growth retardation. During physiological pregnancy, the PL content in the mother's blood gradually increases and during full-term pregnancy is from 6 to 15 μg / ml, then the decrease in PL in women after 30 weeks. pregnancy to the level less than 4 μg / ml is threatening to the fetus. A few weeks before the death of the fetus, the level of PL drops sharply. With insufficient function of the placenta, a moderate decrease in the level of PL in the blood is observed. The results of determining the PL content, obviously, cannot be used as the only diagnostic criterion for fetal hypoxia.
However, in modern clinical practice, the determination of the level of estriol in the blood and its excretion in the urine has not found widespread use, especially since the determination of estriol gives about 80% of false-positive results. The determination of the level of placental lactogen has the same low value. Currently, they have been replaced by methods of ultrasound examination and electronic monitoring of the fetus.
Most informative are considered biophysical methods for assessing the condition of the fetus . These include: electro- and phonocardiography, echography and cardiotocography, which are widely used in the daily work of an obstetrician.
Methods for the study of fetal cardiac activity are also indirect (from the abdominal wall of the uterus) electrocardiography and fetal phonography. When analyzing antenatal ECG determine Heart rate, the nature of the rhythm, the size, shape and duration of the ventricular complex. With fetal hypoxia, violations of the conduction of the heart are detected, a change in the amplitude and an increase in the duration of heart sounds, their splitting. The occurrence of murmurs, especially systolic, during chronic fetal hypoxia indicates its serious condition.
FCG presented oscillations reflecting I and II heart sounds. The pathology of the umbilical cord is characterized by the appearance of a systolic murmur on the PCG and an uneven amplitude of heart sounds.
Ultrasound procedure is the most reliable and accurate method of antenatal diagnosis of fetal health.
The method allows:
To carry out dynamic fetometry,
Evaluate the general and respiratory movements of the fetus,
Cardiac activity of the fetus,
The thickness and area of the placenta,
Amniotic fluid volume
· To measure the rate of fetal-uterine blood circulation.
First of all, they define biparietal size of the fetal head (BPD), mean diameters of the chest (DG) and abdomen (DW). A reliable sign of fetal growth retardation is a discrepancy of 2 weeks. and more BPD of the fetal head to the actual gestational age, as well as disturbances in the relationship between the size of the fetal head and trunk. Comprehensive ultrasound assessment of fetal growth rates allows early diagnosis and an objective assessment of the condition of the fetus.
Is of great importance the study of the respiratory movements of the fetus... To analyze the respiratory activity of the fetus, the following indicators are used: the index of respiratory movements of the fetus (the percentage of the time of respiratory movements to the total duration of the study); fetal respiratory rate (number of breaths per minute); the average duration of episodes of respiratory movements; the average number of breaths per episode. The duration of the study should be at least 30 minutes. In the absence of fetal respiratory movements, the study is repeated the next day. The absence of respiratory movements during 2-3 studies is regarded as a poor prognostic sign. Signs of fetal suffering are changes in the nature of respiratory activity in the form of a sharp decrease or increase. With severe fetal hypoxia, the nature of fetal movements changes. Respiratory movements appear in the form of hiccups or intermittent breathing with prolonged episodes of apnea.
The most accessible, reliable and accurate method for assessing the condition of the fetus during the last trimester of pregnancy is fetal cardiotocography (CTG). The cardiotocograph is designed in such a way that it simultaneously records the fetal heart rate, uterine contractions and fetal movement. Modern cardiotocographs meet all the requirements put forward for monitoring the fetal heartbeat and uterine contractile activity both during pregnancy and during childbirth. Currently, it is generally accepted to conduct screening control of the condition of the fetus both on an outpatient basis and in a hospital. In risk groups for perinatal losses, screening control is carried out over time. Usually, the registration of the fetal heart rate is applied from 30 weeks. pregnancy on a tape moving at a speed of 10 to 30 mm / min, for 30 minutes.
To characterize the condition of the fetus using CTG, the following indicators are used: basal heart rate, variability of basal rhythm, frequency and amplitude of oscillations, amplitude and duration of accelerations and decelerations, fetal heart rate in response to contractions, fetal movements and functional tests.
Under basal rhythm (BR) understand the long-term change in heart rate. A decrease in it below 120 beats / min is classified as bradycardia, and an increase over 160 beats / min is classified as tachycardia. Therefore, a long-term heart rate in the range of 120-160 beats / min is regarded as a normal area. Tachycardia is distinguished by severity: mild (160-170 beats / min) and severe (more than 170 beats / min). Bradycardia is also divided into mild (120-100 beats / min) and severe (less than 100 beats / min) severity. If bradycardia manifests itself in a time interval of no more than 3 minutes, and then it returns to the original BR, then it is called deceleration.