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Prenatal age and fetal weight



It is well known that children are not only and not just "little people." Their diseases are in many ways different from the pathology of adults. It is this circumstance that underlies the allocation of the section of pediatric pathology in a private course of human pathology. By the beginning of the XXI century. in developed countries, great strides have been made in reducing child morbidity and mortality.

Depending on the incidence of these or other diseases, it is convenient to subdivide the whole development of the infant and child into 4 periods: the neonatal period (during the first 4 weeks of life); the period of infancy (1st year of life); interval from 1 to 4 years and the period from 5 to 14 years. The first period is the most vulnerable of them: there are not only all kinds of perinatal pathologies caused by intrauterine growth retardation, prematurity, respiratory distress syndrome, asphyxia, birth trauma, but also such conditions as congenital anomalies, sudden infant death syndrome, etc. O the most important of them will be discussed below.

Let us briefly discuss the explanation of some terms and indicators. The word "antenatal" means "intrauterine or prenatal", "neonatal" - referring to the neonatal period, the term "perinatal" refers to the period from the 22nd full week of fetal life on the 7th day of a newborn, and "postnatal" means postnatal. In 1953, V. Apgar (V.Apgar) proposed a method for determining the state of a newborn during the first minutes of life based on the sum of 5 clinical signs expressed in points. This method became popular and received the name Apgar score (tab. 22.1). Assessment produced after 1 and 5 min after birth. It is known that deviations in the time of intrauterine finding of the fetus from the normal gestational age have an adverse effect on the morbidity and mortality of infants and children.

Table 22.1. Assessment of the condition of the newborn on the Apgar scale

Sign of Points
0 one 2
Heart rate Not defined Below 100 / min Above 100 / min
abbreviations is lying
Breathing depth Not defined Small breathing Normal, resistant
is lying uneven ground driven by a cry
Muscle tone Weak Not determined There is a normal
big bending Naya motor
extremities activity
Reaction to availability Missing Grimace Cough and Sneeze
catheter in the nostril (op
discharged after the eyes
nasopharynx)
Skin color Bluish, Pink on the body Pink everywhere
wow pale but bluish naturally
on the limbs
Prematurity Premature infants consider children born before 37 weeks of gestation, with a body weight of less than 2500 g and height less than 45 cm. The frequency of preterm birth is variable, on average in economically developed countries it is 5-10%. Causes of miscarriage are varied, and they are not always obvious. Often we have to talk about the alleged cause of preterm labor. In many cases, miscarriage due to a complex of reasons. Among the many risk factors for the birth of a premature baby, socio-economic reasons play an important role: the lack or insufficiency of medical care, unfavorable living conditions, stress, occupational hazards. Premature birth of children is more often observed in women younger than 18 and older than 30 years. Previous medical abortions (especially repeated), a small interval between pregnancies, bad habits of the mother - all this increases the risk of premature birth. Miscarriage may be due to chronic somatic and gynecological diseases, endocrinopathy, gestosis. Congenital malformations of the fetus of various etiologies are often also combined with miscarriage. Miscarriage is also characteristic of intrauterine infections, especially in cases where the infection occurred in an ascending way.

Premature babies are characterized by high neonatal mortality, and the shorter the gestation and body weight, the higher the mortality of children. Thus, children weighing less than 1,500 g make up less than 1% of all live births, but they account for 70% of neonatal deaths; 50% of babies with a score of 0-1, estimated 5 minutes after giving birth on the Apgar scale, die within the first month of life. The percentage of perishing decreases to 20 with 4 points and almost to 0 with 7 or more. The high incidence of premature babies is also a serious biomedical problem. Very often, these children develop respiratory failure, which is associated with the immaturity of the lung tissue, increased flexibility of the cartilage of the chest and insufficient development of the pectoral muscles, and the immaturity of the central respiratory regulation mechanisms. Many premature newborns need intubation and mechanical ventilation immediately after birth. A serious problem is the imperfection of temperature regulation. The most frequent diseases and conditions of premature babies are as follows: perinatal asphyxia, hypothermia, hypoglycemia, respiratory distress syndrome, abnormalities of water-salt metabolism, hyperbilirubinemia, intracranial hemorrhage, open arterial duct, necrotizing enterocolitis, infections, retinopathy, broncho-pulmonary artery, necrotizing enterocolitis, infections, retinopathy, broncho-pulmonary artery, necrotizing enterocolitis, infections, retinopathy, broncho-pulmonary artery, necrotizing enterocolitis, infections, retinopathy, broncho-pulmonary artery, necrotizing enterocolitis, infections, retinopathy, broncho-pulmonary artery, necrotizing enterocolitis, infections, retinopathy, broncho-pulmonary artery, necrotizing enterocolitis, infections, retinopathy, broncho-pulmonary lesion

Premature babies have fluffy hair on the face, shoulders, and back. The auricles have a soft consistency due to poor cartilage development. Nail plates on the fingers and toes do not completely cover the nail beds. The bones of the skull are also soft. In boys, the testicles are not lowered into the scrotum, in girls, the labia majora do not cover the small lips. The nuclei of ossification in the epiphysis of the long tubular bones are missing or underdeveloped (in the full-term mature fetus, the core of ossification of the lower epiphysis of the femur reaches 5-6 mm). The internal organs of a premature newborn have macro- and microscopic features, since the process of histogenous and organogenesis occurs actively throughout the entire



Fig. 22.5.

Light 22 week fetus

. In the loose stroma visible alveolar passages, lined with a prismatic epithelium.

ritrobic life (and continues after birth). A prematurely born child has signs of immaturity of organs and tissues, which, as a rule, is pathogenetically associated with diseases of the perinatal period.

Lungs. During the first half of intrauterine life, the development of the lungs occurs through the formation of a system of branching tubes from the epithelium of the foregut. These tubules are the precursors of the trachea, bronchi, bronchioles. The bronchial segmentation ends by week 16, after which the aninuses are lined with cubic epithelium (Fig. 22.5). Alveolar differentiation begins only at the 24th week of gestation, the first osmiophil lamellar bodies appear in the epithelial cells. At this stage, the alveoli are lined with cubic epithelium. Between the 26th and 32nd weeks, the cubic epithelium flattens, differentiates into alveolar monstrosities of the 1st and 2nd types. Initially, the septa between the alveoli contain a large amount of connective tissue, the capillaries do not have close contact with the lumen of the alveoli, so the ability to gas exchange in the lungs is low. Further differentiation of the lungs leads to a decrease in the number of connective tissue and an increase in the number of capillaries. But even in a full-term newborn, the alveoli are small and



Fig. 22.6.

26 week fetus

.
Primitive glomeruli in the subcapsular zone.

the births are thicker than those of an adult. Type 2 alveolocytes are few, they appear in small groups, mainly in the branching points of the alveolar passages. The development of alveoli continues after birth. The lungs of a child begin to correspond to the lungs of an adult only by 8 years of age.

Brain. Studying the brain of a premature baby, it should be remembered that the convolutions appear on the surface of the brain only from the 20th week of intrauterine development. The substance of the brain to the touch is soft, gelatinous, easily damaged. The boundary between gray and white matter is not pronounced, due to the incomplete myelination of nerve fibers. Despite this, in a premature newborn, vital centers are already formed. However, their coordination is still imperfect; therefore, in premature infants, there are frequent violations of thermoregulation and poor regulation of vascular tone, central respiratory disorders, and muscular hypotension are noted.

Kidney. In a premature baby in the subcapsular zone, you can see primitive glomeruli. These structures resemble the structure of the gland, since the parietal and visceral leaflets of the glomerulus capsule (Bowman's capsule) are lined with a cubic epithelium (Fig. 22.6). The glomeruli located in the deep layers of the bark are well formed.



Fig. 22.7.

24 week fetus liver

. Among hepatocytosis, there are many immature cells of myeloid and erythropoiesis.

Liver. In premature babies, the liver is relatively large, but the formation of its functions is not complete. Characteristic immaturity of enzyme systems - glucuronyltransferase, hydroxylase. The protein synthesizing function is underdeveloped. Physiological jaundice, which occurs after birth and is caused by the destruction of fetal hemoglobin, in premature babies is more pronounced and prolonged due to insufficient activity of enzyme systems. The level of indirect bilirubin can be so high that it causes damage to the central nervous system. A distinctive feature of the liver premature is the severity of extramedullary hematopoiesis (Fig. 22.7).

The adrenal glands. The adrenal cortex is formed by the 21-22nd week. It consists of definitive and fetal cortex. The definitive cortex is formed from cells of the glomerular zone located subcapsularly; in more mature fruits, the beginning of the formation of the puchal zone can be seen. The fetal cortex consists of large polygonal cells located in the form of radial cords and possessing light large nuclei and vacuolation cytoplasm (Fig. 22.8). After the baby is born, the fetal cortex is reduced. The brain substance is represented by small groups of large basophilic cells.



Fig. 22.8.

Adrenal cortex of the 23-week fetus

. The fetal cortex is represented by large polygonal cells with eosinophilic cytoplasm. Small cells of the definitive cortex form a narrow layer under the organ capsule. Differentiation into zones is absent.

Torsion Newborn babies are born later than 42 weeks gestation. With a post-term pregnancy, the fetus can continue to grow and becomes unusually large. Under adverse conditions of intrauterine development in a newborn, on the contrary, there may be a shortage of adipose and muscle tissue. During childbirth at 42 weeks, perinatal mortality increases by 2 times, and at 43 weeks - by 3 times compared with the mortality of children born at 38-40 weeks. Common causes of death: asphyxia, meconium aspiration syndrome, polycythemia, hypoglycemia [meconium is the intestinal contents of the fetus and newborn (from the 3rd month of intrauterine development to the 2-3rd day of life); polycythemia - erythrocytosis]. R due to high perinatal mortality with a gestational age of more than 42 weeks, induce labor.

Excessive children have no cheese lubricant, the skin is dry, flaky. Partial maceration of the skin is possible. In severe cases, there is staining with meconium of the skin, nails and umbilical cord. In the proximal epiphysis of the tibial and humeral bones, nuclei of ossification appear, which are not present in full-term newborns.

Intrauterine growth retardation. The mass of an unborn child is of great importance for predicting its health, however, when assessing the viability of the fetus, it is important to take into account not only absolute mass indices, but also its conformity with the gestational age (gestational - relating to pregnancy). The mass of an unborn child can meet the norm for a given period of pregnancy, not reach or exceed it.

Adequate growth depends on providing the fetus with nutrients that may be impaired with diseases and maternal nutritional deficiencies, placental insufficiency, diseases of the fetus itself. Fetal growth also depends on its endocrine status. Growth hormones and thyroid hormones do not affect fetal growth. Anabolic and growth functions are performed by other hormones, in particular, insulin and insulin-like growth factor 2. Insulin acts on the fetus as a growth hormone, but it does not penetrate the placenta and must be secreted by the fetus itself. Hyperinsulinism in utero, affecting the fetus in women with diabetes mellitus, is accompanied by an increase in fetal weight. In the absence of production of insulin by the fetus, for example, under the conditions of the genesis of pancreatic islets (islets of Langerhans), the growth of the fetus slows down. When fetal hypotrophy in its blood, the content of C-peptide is reduced - a protein that binds proinsulin.

Delays in fetal growth and fetal development are diagnosed in children who have a body weight below 10 percentiles for a given gestational age (the percentile is the percentage of the average statistical value of the infant's weight at a given gestational age). The reasons for the delay are divided into 3 main groups: fetal, maternal and placental.

Fetal causes: genetic - racial, ethnic, familial, chromosomal diseases (trisomy 13, 18, 21, monosomy X, triploidy), gene diseases (Russell's syndromes — Silver, Dubowitz, leprechaunism, chondrodysplasia); female sex (girls' body mass is 150–200 g less than that of boys); intrauterine infections (cytomegalovirus, toxoplasmosis, herpes, rubella). Maternal causes: hypertension, toxicosis, nutritional deficiencies, chronic hypoxia (diseases of the lungs, heart, blood, smoking), alcohol, drugs, small stature, body weight less than 50 kg before pregnancy, multiple pregnancy. Placental causes: hypoplasia, detachment, presentation, placental infarction, infection, umbilical cord anomalies.

Children with intrauterine growth retardation and development have higher incidence rates compared with children with a normal body weight for a given gestational age. In children with this delay, the frequency of perinatal asphyxia, hypothermia, hypoglycemia, and infectious diseases is increased. Intrauterine growth retardation and development, as a rule, is combined with a lag in the maturation of the internal organs. Mortality in the group of children with intrauterine growth retardation and development is 3-5 times higher than the average. For example, in children born on the 36th week of pregnancy and having a birth weight of 1250 g, the risk of mortality is estimated at 6%, and in children with the same gestational age, but with a body weight of 3000 g - in 0.2%.

Growth retardation can be symmetrical when body weight, length and head circumference are reduced by an equal number of percentiles. This is a hypoplastic variant of intrauterine growth retardation and development. This option is observed if growth is impaired in the first and second trimesters of pregnancy. The majority of children in the organs reduced the number of cells. The hypoplastic variant is characterized by a poor prognosis.

If the height and circumference of the head are normal or reduced to a smaller proportion than the body weight of the child, this “asymmetric” form is called the hypotrophic variant of intrauterine growth retardation and development. It is celebrated in the last 2-3 months of pregnancy; children have an increased risk of perinatal complications, but in general the prognosis is somewhat more favorable than with the hypoplastic variant.

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Prenatal age and fetal weight

  1. DISEASES OF THE PERINATAL PERIOD. GESTATION AGE AND FETUS MASS. INTRAINTEGRATED HYPOXIA. BIRTH INJURY. GENERIC DAMAGES OF HYPOXIC GENESIS. PULMONARY DISEASES OF THE PERINATAL PERIOD. CONGENITAL DEVELOPMENTAL DISEASES. INTRAUTERNAL INFECTIONS. HEMOLYTIC DISEASE OF NEWBORNS
    The perinatal period of development is the period from the 22nd full week of intrauterine fetal life to 7 full days after the birth of a child. The gestational age of the fetus is determined by the duration of pregnancy. The duration of pregnancy is measured from the first day of the last normal menstruation. The average duration of pregnancy is 280 days (40 weeks). Full-term is considered a child born
  2. Intrauterine growth retardation.
    Delays in fetal growth and fetal development are diagnosed in children who have a body weight below 10 percentiles for a given gestational age (the percentile is the percentage of the average value of the infant's weight at a given gestational age). Causes of intrauterine growth retardation are divided into fetal, maternal and placental. Intrauterine growth retardation is often observed during intrauterine growth.
  3. Intrauterine fetal death
    Intrauterine fetal death - fetal death during pregnancy or during childbirth. Fetal death during pregnancy refers to antenatal mortality, death during childbirth - intranatal death. Causes of antenatal death of the fetus can be infectious diseases of a pregnant woman (influenza, typhoid fever, pneumonia, pyelonephritis, etc.), extragenital diseases (congenital heart defects,
  4. Intrauterine bacterial infection of the fetus
    Intrauterine bacterial infection of the fetus can be caused by both pathogenic (staphylococcus, streptococcus, etc.) and conditionally pathogenic (enterobacteria, Klebsiella, Proteus, etc.) microorganisms, as well as mycoplasmas. Infectious agents can enter the body of the fetus transplacentally if the mother’s body has focal infections (tonsillitis, sinusitis, dental caries, pyelonephritis and
  5. Fetal death of the fetus. Fetal operations
    Fetal death during pregnancy refers to antenatal mortality, death during childbirth - intranatal death. Causes of antenatal death of the fetus can be infectious diseases of a pregnant woman, extragenital diseases, inflammatory processes in the genitals. The cause of death of the fetus can be severe OPG gestosis, pathology of the placenta and the umbilical cord, entanglement of the umbilical cord around the neck of the fetus,
  6. Principles of diagnosis of intrauterine hypoxia
    Hypoxia and acidosis are a consequence of a number of adverse changes in the fetus, leading to severe damage to the life support systems of the fetus and its death. The main task of antenatal diagnosis is the early detection of hypoxia and the selection of the optimal time and method of delivery. The most common non-invasive methods for assessing the functional state of the fetus include the following studies:
  7. Intrauterine fetal circulation
    Oxygenated blood flows through the placenta through the umbilical vein to the fetus. A smaller part of this blood is absorbed into the liver, a large - into the inferior vena cava. Then this blood, mixed with blood from the right half of the fetus, enters the right atrium. Blood is also poured in from the superior vena cava. However, these two blood pillars almost do not mix with each other. Blood from the inferior vena cava through
  8. Prevention and treatment of fetal hypoxia during pregnancy and childbirth
    By intrauterine hypoxia, we mean a violation of gas exchange between the mother and the fetus, expressed in a decrease in the supply of oxygen to it and in the accumulation in the body of oxidized oxidation products. Metabolic acidosis develops in the fetus. The increase in the phenomena of acidosis leads to inhibition of biochemical processes in the cells of the fetus, to a decrease in their ability to absorb oxygen, and in
  9. Fetal death of the fetus. Fetal operations
    Fetal death of the fetus. Fruit destructive
  10. Intrauterine infection of the fetus by trimesters of pregnancy
    Intrauterine infection of the fetus by developmental trimesters
  11. WRONG POSITION OF THE FETAL OPERATION, CORRECTING THE POSITION OF THE FRUIT. OBSTETRIC TURNS FETAL EXTRACTION IN THE TAZE END
    ANOMALIES OF THE FRUIT POSITION The position of the fetus is called correct when the axis (longitudinal axis) of the fetus coincides with the axis of the uterus. If the fetus axis crosses the uterus axis at any angle, an incorrect position of the fetus occurs, at which the course of labor becomes dangerous for the mother and the fetus. Incorrect positions include the transverse and oblique position of the fetus. The transverse position of the fetus is called
  12. WRONG POSITION OF THE FETAL OPERATION, CORRECTING THE POSITION OF THE FRUIT. OBSTETRIC TURNS FETAL EXTRACTION IN THE TAZE END
    ANOMALIES OF THE FRUIT POSITION The position of the fetus is called correct when the axis (longitudinal axis) of the fetus coincides with the axis of the uterus. If the fetus axis crosses the uterus axis at any angle, an incorrect position of the fetus occurs, at which the course of labor becomes dangerous for the mother and the fetus. Incorrect positions include the transverse and oblique position of the fetus. The transverse position of the fetus is called
  13. Body mass
    A full-term baby at birth weighs from 2500 g to 4000 g. After birth, children have a physiological decline in weight, which should not be higher than 8% of the body weight of the child. The greatest loss of body weight occurs on the 4th-5th day, but by the 10th day of life the child has the same indicators as at birth. Causes of weight loss after childbirth are: 1) water loss with breathing,
  14. Signs of maturity of the fetus, the size of the head and body of a mature fetus
    The length (height) of a mature full-term newborn varies from 46 to 52 cm and more, averaging 50 cm. The fluctuations in the body weight of a newborn can be very significant, but the lower limit for a full-term fetus is 2500–2600 g. The average body weight of a mature full-term newborn. 3400–3500 g. In addition to body weight and the length of the fetus, its maturity is judged by other signs. Have
  15. Childbirth at loss of small parts of the fetus, large fruit, fetal hydrocephalus
    Presentation and loss of fetal stem. Complications are extremely rare with headache presentation, for example, with a premature and macerated fetus, as well as with twins, if there is a sharp bending of the body of the fetus with the leg extended. If it is impossible to straighten the stem with a viable fetus, a cesarean section is shown. Childbirth large and giant fruit. Childbirth with malformations and
  16. Signs of maturity of the fetus, the size of the head and body of a mature fetus
    The length (height) of a mature full-term newborn varies from 46 to 52 cm or more, averaging 50 cm. The average body weight of a mature full-term newborn is 3400–3500 g. The mature full-term newborn has a well-developed subcutaneous fat layer; skin pink, elastic; downy coat is not expressed, the length of hair on the head reaches 2 cm; ear and nose cartilages are elastic; nails are tight
  17. Childbirth at loss of the umbilical cord loop, small parts of the fetus, large fruit, fetal hydrocephalus
    If outwardly the internal classic rotation fails, the childbirth is terminated using a cesarean section. Presentation and loss of fetal stem. Correct diagnosis is necessary, since this complication can be mistaken for incomplete leg laying and improper extraction of the fetus can lead to its death. Complications are extremely rare when
  18. Mechanisms of protection from the fetus (the formation of the immune system of the fetus)
    During the period of embryogenesis (3-8 weeks), there is a laying, growth and development of all organs of the fetus, including cells of the immune system. At 5 weeks of gestation, the thymus gland is formed, which will become the central organ of the immune system. At the same time, the liver, spleen, lymphatic accumulations along the vessels are formed. From one stem hematopoietic polypotent cell from the 3rd week of development to
  19. Intrauterine infections
    SYNONYMS Congenital infections, TORCH syndrome. DETERMINATION Intrauterine infections (IUI) are a group of infectious and inflammatory diseases of the fetus and newborn, caused by various pathogens, but characterized by general epidemiological patterns and often have similar clinical manifestations. To refer to intrauterine infections that manifest from the first day of life,
  20. Intrauterine hypoxia.
    Intrauterine hypoxia is a state of hypoxemia that occurs in the fetus in violation of uterine = placental or placental-fetal blood circulation. Intrauterine hypoxia can be acute and chronic. Acute intrauterine hypoxia occurs when premature detachment of the placenta, the development of multiple heart attacks in it, the umbilical cord prolapse, the formation of true umbilical cord nodes or its entanglement
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