Characteristics of a premature baby

Since 1961, according to the WHO recommendation, all newborns weighing less than 2500 g have been designated as newborns with "low birth weight". Currently, this position is not shared by many researchers, since it eliminated the concept of "prematurity" and "term intrauterine development" in assessing the condition of the child. Many researchers of newborns with a small body weight are divided into three groups:

1. newborns, the rate of intrauterine growth of which was normal until the moment of birth (body weight corresponds to the gestational age);
2. children born on or terminated, but having a body weight, insufficient for this gestational period, due to a slowdown in intrauterine growth;
3. premature, in which, in addition, there was a slowdown in intrauterine growth, that is, their body weight is insufficient in connection with both prematurity and intrauterine growth disorders.

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

The reason for the birth of premature babies

In most cases, the phenomena of intrauterine growth retardation in primitive women were due to the morphofunctional features of the placenta and the development of placental insufficiency. A comparative analysis of qualitative indicators and quantitative characteristics showed that at births of 28-32 weeks, half, and at delivery in 33-36 weeks - only one third of the offspring had anomalies in the shape and attachment of the umbilical cord. In those cases where pregnancy was occurring with the threat of interruption in the first trimester, the placental changes were sharply expressed. Thus, the index of the placental resorption surface decreased to 3.1 m ² with a gestation period of 28-32 weeks and up to 5.7 m ² at a period of 33-36 weeks.

With the use of general survey methods of morphological investigation in the placenta, a number of changes have been revealed in prematurely born women, to which include massive fibrinoid deposits in the decidual plate and intervillous space with the presence of single X cells, calcification sites, an increase in the number of terminal terminal villuses (sclerotized, edematous, fibrinoid-altered), narrowing of the intervillous space. All these changes characterized dystrophic processes and were more often found in the placentas of women who gave birth within 32 weeks. At the same time, a large number of unchanged terminal villi with syncytial "nodules" of the proliferative type was defined, with dilated, full-blooded and subepithelially located capillaries. These villi caused compensatory-adaptive reactions in the placenta. These features were more often detected in the placentas of women who gave birth after 33 weeks of pregnancy. Stereometric analysis of the placenta confirmed the prevalence of dystrophic processes in the placenta at delivery up to 32 weeks and compensatory-adaptive changes at birth in later periods. In women who underwent acute respiratory viral diseases during pregnancy, histological examination of the placenta, in addition to the indicated changes, showed pronounced disorders of uteroplacental blood circulation in the form of extensive hemorrhages in the decidual platelet, intervillious space and the stroma of the villi.

When analyzing the morphometric data of the placenta and comparing them with the data on the state of preterm infants at birth and in the early neonatal period, it was established that the body weight of newborns, weight and morphometric parameters of the placenta, depending on the gestational age, were reduced in those cases when children were born with signs of intrauterine development. The condition of children born with signs of hypotrophy was assessed on the Apgar scale, usually below 5 points. In the morphological analysis of the placenta, the more pronounced dystrophic processes were observed in those women whose children were born with signs of hypotrophy and up to 32 weeks of gestation. These data were confirmed by a stereometric analysis of the structural elements of terminal villi, where a decrease in the relative areas of the intervillar space was observed. If histological study compensatory changes in the placentas prevailed over the dystrophic, the physical data of the children were normal, and corresponded to the gestational age.

In the electron microscopic study of placenta, changes were observed in all cellular structures of the villous chorion: syncytiotrophoblast, stroma of villi and capillaries. The microvilli covering the syncytiotrophoblast were sometimes absent or unevenly located on the altered terminal villi. The ultrastructure of sclerotized villi was characterized by an increase in the stroma of the amount of collagen fibers going in different directions, and edematous - by a decrease in the number of cellular components with large electron-optically transparent formations of various shapes and numerous septa. The amount of collagen fibers around the capillary confirmed the presence of vascular sclerosis. In this case, endothelial cells lining the inner surface of the capillary were changed. Their nuclei were stretched, the nuclear chromatin was located along the periphery compactly, sometimes with destruction of the cytoplasm. All these changes in the cellular elements of the terminal villus confirmed the presence of a dystrophic process in the placenta. Electron microscopic examination of the placenta also revealed an increase in subepithelial vessels and hyperplastic capillaries, a change in the density of microvilli, and the appearance of syncytiotrophoblast clustered nuclei with swollen mitochondrial rists in syncytium.

As a result of the study of the enzymatic activity of ATPase and 5'-nucleotidase in placentas in preterm labor, the dependence of the reaction product on the changes in various structures of the terminal villus was established. Thus, high enzymatic activity was observed on microvilli, secreting pinocytosis vesicles, syncytium nuclei, cytotrophoblast and endothelial cells, ie, unchanged terminal villuses, where the processes were more often compensatory. So, where the ultrastructural study of the placenta revealed destruction, the enzymatic activity of ATPase and 5'-nucleotidase was reduced. Especially it concerned edematous, sclerotized and fibrinoid-altered villi. Electron microscopy allowed to determine once again in women who gave birth prematurely, the predominance of dystrophic or compensatory processes in the placentas. The results of ultrastructural and ultracytochemical studies confirmed that changes in the placenta indicate the development of placental insufficiency.

Thus, morpho-functional studies of the placenta in preterm labor, conducted with the use of morphometric and electron microscopic methods, made it possible to detect placental insufficiency. In cases of predominance of compensatory-adaptive processes in the placentas over dystrophic pregnancy, the benefit flowed pleasantly and premature babies were born with physical parameters corresponding to the gestational age. With pronounced dystrophic changes in the placenta, the development of placental insufficiency led to intrauterine growth retardation of the fetus complicated by the course of the neonatal period in premature infants and was one of the indications for premature termination of pregnancy.

The main signs of a premature baby

A premature baby is considered to be prematurely born before 38 weeks of pregnancy. Children with a birth weight greater than 2500 g diagnosed with prematurity, according to the international nomenclature (Geneva, 1957) put, if they were born before 37 weeks.

Classification of prematurity with regard to gestational age at the time of birth 

• I degree - 35-37 weeks of pregnancy. 
• II degree - 32-34 weeks of pregnancy. 
• III degree - 29-31 weeks of pregnancy.
• IV degree - less than 29 weeks gestation.

For the physical development of premature babies, a higher rate of weight gain and body length in the first year of life is characteristic (except for the first month). By 2-3 months they double the initial body weight, by 3-5 - tripling, by the year - increase by 4-7 times. At the same time, extremely immature children in terms of absolute growth and body weight significantly lag behind ("miniature" children), 1-3 "corridor" of centile tables. In subsequent years of life, deeply premature babies can maintain a kind of harmonious "delay" of physical development. Evaluation of physical development is carried out on the GM scale. Dementieva, E.V. Short and according to the EA method. Usachevoy, taking into account the gestational age.

The neuropsychological development of premature babies in the first 1.5 years is usually slowed down, the degree of this delay depends on the severity of prematurity, this is a kind of "norm" for immature children. In the absence of a lesion of the nervous system, even extremely immature children by 2-3 years of age in terms of the level of psychomotor development do not differ from full term, although many of them retain emotional lability, fatigue and fast exhaustion of nervous processes.

Anatomical and physiological features of premature infants

Features of the neurological status of prematurity I degree (35-38 weeks) without burdening the neurological status of the factors do not differ from full-term children. In children with II-IV degree of prematurity, the morphological status depends on the degree of maturation of the brain. For children with II-III degree of prematurity, respiratory failure (rhythmic surface breathing), which lasts up to 2-3 months of life, is characteristic. Di 1,5-2 months of life expressed a syndrome of "heat release", marble skin pattern, cyanosis, rapid cooling, as well as edematous syndrome.

Children are sluggish, motor reactions are reduced. The reactions of concentration and initial follow-up begin to form with a satisfactory increase in body weight and the absence of somatic diseases, appearing from 1.5-2 months of life. Muscular hypotension is characteristic up to 2-4 weeks, then replaced by an increased tone in the flexor of the limbs.

Unconditioned reflexes from the group of spinal automatisms (reflexes of support, automatic gait, creeping, etc.) begin to show up with 1-2 months of life. With pre-grade III-IV prematurity, it is difficult to assess the neurological status to 1.5-2 months, since the leading syndrome is a general lethargy, which is also characteristic for central nervous system depression.

It must be remembered that with improper rehabilitation even meager clinical manifestations at the age of 3-4 months of life can subsequently progress.

[4], [5], [6], [7]

Features of neurological status in premature infants

Premature babies are defined as a risk group for psychoneurological pathology. The pediatrician should pay attention to the clinical manifestations of the psychoneurological status. In a premature baby, the syndrome of increased nervous reflex excitability proceeds according to one of the three variants.

In the first case, the clinical picture in an acute period is similar to that of a full-term baby, then decreases and gradually disappears by 6-12 months. At the second variant after a year of life the asthenoneurotic syndrome is formed. In the third variant of the course, the minimal manifestations of the syndrome of increased nervous reflex excitability are transformed into convulsive syndrome (regardless of age). Similar conditions hardly ever occur in full-term children with the syndrome of neural-reflex excitability.

Thus, minimal clinical changes on the part of the nervous system in a premature baby may have irreversible severe consequences, which requires constant dynamic observation by a pediatrician, narrow specialists using instrumental research methods.

Most often, premature babies develop hypertensive hydrocephalic syndrome, proceeding in two ways. Favorable course - first the hypertensive symptoms disappear, in the future there are no signs of hydrocephalus. Unfavorable course - outcome in infantile cerebral palsy, hydrocephalic and convulsive syndromes.

The CNS depression syndrome is typical for children with grade III-IV prematurity. It shows not only neurological, but also somatic discomfort, is typical for subarachnoid and parenchymal hemorrhages, bilirubin brain lesions, which occur with conjunctive jaundice in immature premature infants.

The convulsive syndrome can be noted in the first days of life. His clinic is typical. Sometimes in the recovery period, after 4-6 months of life, there are attacks of apnea, a sharp redness or cyanosis of the face, a marbled skin pattern, a Harlequin symptom, increased sweating, regurgitation, nodding head movements or flexing the trunk forward and back. These prognostically unfavorable symptoms may first occur against intercurrent diseases, indicating irreversible changes taking place in the central nervous system. For all premature babies, there is a syndrome of vegetovisceral dysfunctions, the severity of which depends on the degree of prematurity, timeliness, and the volume of rehabilitation measures carried out.

The child born prematurely shows signs of immaturity: body weight less than 2500 g, body length less than 45 cm, a lot of raw lubricant, insufficient development of subcutaneous fat, fluffy nail (normally it is noted only on the shoulder girdle), a small length of hair on the head , soft ear and nasal cartilages, nails do not go beyond the fingertips, the umbilicus is located closer to the bosom, the boys do not have testicles in the scrotum, the clitoris and the labia minora are not covered with large lips, the child's cry is thin (squeaky).

Assessment of the degree of maturity is carried out on a special scale (WHO, 1976). At the same time, the term of intrauterine development of the newborn can be estimated to within 2 weeks. When assessing the degree of maturity, it is necessary to take into account the gestational age at which labor occurred.

Assessment of the child's state on the Apgar scale was proposed for a full-term newborn, but this scale can be successfully used with preterm delivery. The increased frequency of oppression of vital parameters in a premature baby correlates with low estimates of the condition at birth. According to many researchers, with a body weight of up to 1500 g, the state is estimated on the Apgar scale from 0 to 3 points in about 50%, while at a weight of 3000 g - only 5-7% of newborns. A great prognostic value is the assessment of the child's state on the Apgar scale 5 minutes after birth. If it remains low, then the forecast is unfavorable.

In recent years, it has been established that in utero the fetus performs respiratory movements that can be recorded with the help of ultrasound equipment. If these movements are absent or significantly weakened, then the disease of hyaline membranes develops more often in newborns. With nephropathy or diabetes in the mother, the frequency of episodes of respiratory movements in the fetus is reduced. Intrauterine respiration is a new parameter, which, apparently, will allow more accurate assessment of the fetal organism's readiness for extrauterine respiration. The mechanism of the first inspiration is rather complicated, and the role of stimuli of this process is not sufficiently studied, especially in children born in different gestational periods. Great importance in the excitation of the respiratory center at the time of birth has asphyxia, which can be observed as a short episode at the time of the birth of the child. Decrease in PO2 and pH, increase in PCO2 stimulate respiratory movements, causing impulses from carotid and aortic chemoreceptors. Such short episodes of asphyxia, which are observed in the process of normal delivery, are characterized by the absence of metabolic acidosis. Prolonged asphyxia is accompanied by the appearance of metabolic and respiratory acidosis and leads to depression of the respiratory center.

Another important stimulus to the onset of breathing is a sharp drop in the temperature of the environment surrounding the baby at birth. A decrease in temperature stimulates the nerve endings in the baby's skin, these stimuli are transferred to the respiratory center. They are an intensive stimulator of respiration. However, the excessive cooling of the newborn leads to a deep depression of the child's vital activity. Tactile stimulation, created with the usual touch to the child at the time of delivery, also stimulates the onset of breathing. The end result of the extrauterine activity of the respiratory muscles is the creation of a fetal lung at a lower pressure than in the atmosphere. Negative intrathoracic pressure contributes to the intake of air into the lungs. The main role in the normal functioning of the lungs is played by the diaphragm.

Adaptation of the cardiovascular system to extrauterine life occurs simultaneously with the adaptation of the lungs. The expansion of the lungs and the adequate oxygenation that occur in the child with the onset of respiratory movements cause a decrease in blood pressure in the small circle of circulation in connection with the expansion of pulmonary arterioles. At this time, the blood pressure in the great circle of blood circulation is significantly increased due to the switching off of the placental blood flow. Due to the change in the ratio of blood pressure values, conditions are created for eliminating the mixing of venous and arterial blood, closing the oval window and the arterial and then the venous duct. .

To assess the function of breathing at birth and the following days, the Silverman scale is increasingly being used, according to which the respiratory function of a newborn is characterized by:

• movement of the chest and retraction of the anterior abdominal wall on inspiration;
• retraction of intercostal spaces;
• retraction of the sternum;
• the position of the lower jaw and the participation of the wings of the nose in the act of breathing;
• the character of breathing (noisy, with a groan).

Each of these symptoms is estimated from 0 to 2 points as its severity increases. The sum of the scores gives an idea of the function of breathing in a newborn. The smaller the Silverman score, the less pronounced manifestations of pulmonary insufficiency. When nursing preterm infants, adequate breathing and normal functioning of the lungs are necessary. It is especially important not to disturb the mechanism of the first inspiration, therefore, all manipulations for sucking mucus from the upper respiratory tract should be carried out extremely carefully.

Maintaining an optimal ambient temperature is one of the most important aspects of the effective care of a premature baby. The anatomical features of prematurity are such that they predispose to loss of heat, and their heat balance is less stable than in children with a larger body weight.

In newborns with a small body weight, its surface is relatively large. The large surface of the body causes more extensive contact with the external environment, increasing heat losses. The loss of heat per unit mass in a premature baby with a body weight of 1500 g is 5 times greater than that of an adult. Another anatomical obstacle to the preservation of heat is a very thin layer of subcutaneous fat, so that heat is quickly transferred from the internal organs to the surface of the skin.

The position of the child also affects the rate of heat loss. With bent extremities, the surface of the body decreases and, accordingly, heat transfer. The tendency to flexion of limbs increases with the increase in the term of intrauterine development. The smaller it is, the more heat the newborn loses. These factors significantly affect the ability of the newborn to survive, the speed of recovery after asphyxia, the effectiveness of therapy of respiratory disorders, as well as the rate of weight gain.

Under the influence of cold due to the activation of metabolism in the newborn increases the rate of recoil. This phenomenon is observed in both full-term and preterm infants, although the latter have a much faster rate of heat transfer. The main metabolic disorders in newborns that have undergone a cooling include hypoxemia, metabolic acidosis, rapid depletion of glycogen stores and a decrease in blood sugar levels. The increase in metabolism entails an increase in oxygen consumption. If the oxygen content in the inhaled air is not increased, then PO2 drops in blood. In response to hypothermia, norepinephrine is secreted, which leads to narrowing of the pulmonary vessels. In this regard, the effectiveness of ventilation decreases, which leads to a decrease in the partial pressure of oxygen in the arterial blood. In this case, the decomposition of glycogen and its conversion into glucose take place under conditions of hypoxia, and in the case of anaerobic glycolysis, the rate of cleavage of glycogen is many times higher than in the case of aerobic glycogen, resulting in hypoglycemia. In addition, in the process of anaerobic glycolysis a large amount of lactic acid is formed, which leads to an increase in metabolic acidosis.

These disorders occur as soon as the baby is premature, since the glycogen reserves are insignificant, and are especially reduced in newborns with insufficient oxygenation during atelectasis due to immaturity of the lungs and other respiratory disorders. For such newborns, maintaining the thermal regime of the environment is vitally important. The body temperature drops right after birth. To some extent, this is a physiological process, since stimulation of the skin receptors is necessary to stimulate the first inhalation. In the usual delivery room, the temperature in a full-term newborn is reduced by 0, 1 ° C in the rectum and by 0.3 ° C on the skin per minute. In a premature baby, these losses are even more significant, especially if a breathing disorder is observed at the same time.

A significant amount of heat is lost when evaporation of the amniotic fluid from the body of the child. To reduce these losses, a premature baby should be taken into warm diapers, wiped and placed on a table heated from above by a heat source, or into a bowl heated to 32-35 ° C. Maintaining a thermal regime in the first days of life is the first priority when nursing preterm.

Premature newborns do not tolerate stressful situations that arise in connection with the onset of extrauterine life. Their lungs are not mature enough for gas exchange, the digestive tract can not absorb 20-40% of the fat contained in milk. Their resistance to infection is low, and an increase in the rate of heat loss disrupts thermoregulation. The increased fragility of capillaries predisposes to hemorrhages, especially in the ventricles of the brain and the cervical spinal cord. The most common diseases to which predisposed preterm infants are predisposed are hyaline membrane diseases, intracranial hemorrhages, infection, asphyxia.

[8], [9], [10], [11], [12], [13],

Complications in premature infants

The most severe complication of the postnatal period of life in a premature baby is hyaline membrane disease, or respiratory distress syndrome. Most often, this disease is observed in children with a body weight at birth of 1000-1500 g and less. In most cases, newborns in the lung have a surfactant that provides effective respiration. A small amount of it is produced with the participation of methyltransferase from 22-24 weeks of intrauterine life. After birth, the production of surfactant l in this way stops under the influence of hypoxia. Synthesis of surfactant by a more stable system with the participation of phosphocholine transferase begins at 34-35 weeks of intrauterine life; this system is more resistant to acidosis and hypoxia. At birth, and soon afterwards, a premature baby can breathe without difficulty, but because the surfactant is consumed and the new system synthesizes it in a small amount, the normal functional residual capacity of the lungs is not established. The alveoli, which inflate when inhaled, subside during exhalation. Every subsequent breath requires incredible efforts from the child.

As the child weakens, atelectasis increases, which leads to the development of hypoxia and hypercapnia. As the anaerobic pathway of glycolysis prevails, metabolic acidosis arises. Hypoxia and acidosis increase vasospasm, resulting in reduced blood flow to the lungs. Hypoxia and acidosis lead to damage to the capillaries and necrosis of the alveoli. In the alveoli and terminal respiratory bronchioles, hyaline membranes are formed from cell death products, which by themselves, without inducing atelectasis, significantly reduce the elasticity of the lungs. These processes further disrupt the production of surfactant. Insufficient expansion of the lungs and preservation of high vascular resistance of the lungs lead to an increase in blood pressure in the small circle of the blood circulation, as a result of which the intrauterine type of circulation (oval window, arterial duct) is preserved. The effect of these extra-pulmonary shunts is expressed in the removal of blood from the lungs, and: the child's condition progressively worsens. At the threat of premature birth and at the time of birth, the prevention of hyaline membrane disease in the child (maintaining the temperature regime, sufficient oxygenation, fighting acidosis) is necessary. Modern methods of intensive therapy can significantly reduce mortality in this disease. In the neonatal period, preterm infants have signs of intrauterine growth retardation. Such conditions are most typical for children born to mothers with extragenital pathology and toxicosis of the second half of pregnancy. At the same time, as our studies have shown, children with hypotrophy phenomena are often born even in primitive women without any other complications of pregnancy. Hypotrophy is detected more often in preterm labor in 28-32 weeks of pregnancy (67%). At delivery in 33-36 weeks, the frequency of birth of children with signs of intrauterine growth retardation is only 30%.

[14], [15], [16], [17],

Survey of Premature Children by Narrow Specialists

On the 1st month of the child the neurologist, oculist, otorhinolaryngologist examines; all children born prematurely are subjected to audiological screening. Children born with a body weight of 1500 g or less, as well as all preterm infants who have been on intensive care or artificial ventilation of the lungs, are shown conducting an indirect binocular ophthalmoscopy to detect signs of retinopathy.

Mandatory laboratory and instrumental methods of investigation

• The general analysis of blood in 1 and 3 months, in the second half of the year. 
• The general analysis of urine in 1 and 3 months, in the second half of the year. 
• Coprologic examination 2 times a year. 
• Bilirubin of blood is monitored up to 1 month, then according to the indications. 
• Neurosonography at the age of up to a month, then according to the indications. 
• Ultrasound of the hip joints before the age of 3 months.

According to the testimony: 

• biochemical blood tests;
• computed tomography and magnetic resonance imaging.

In the future, it is necessary to make an individual schedule of dispensary follow-up depending on the degree of prematurity and the clinical and functional characteristics of the respective health groups.

Tactics of preterm infants at the pediatric site

Premature babies in the first year of life are usually observed according to the scheme provided for children of the 2nd and 3rd groups of health.

Clinical follow-up of premature babies in a polyclinic presupposes a differentiated control of their physical and neuropsychic development, peripheral blood counts, as well as systematic examinations by narrow specialists (neuropathologist, orthopedist, oculist, according to indications - surgeon, allergist, etc.).

Individually appoint a mode of the day with a delay of 2-4 weeks or more compared with peers, taking into account the clinical picture.

The nature of feeding is planned individually. When breastfeeding naturally, additional fortification is necessary (Pre-Semp, Friesland Foods, FM-8, Breast milk fortifier), which are specialized protein-mineral or protein-vitamin mineral supplements. Adding fortificators to the diet eliminates the deficiency of nutrients. It is possible to introduce in the volume of 20-30% of the need for artificial mixtures based on hydrolysates of whey proteins (Nutrilak Peptidi SCT, Alfare, Nutrilon Pepti SCT). With the artificial feeding of premature babies, specialized mixtures are used (Pre NAN, Pre Nutrilak, Per Nutrilon, Humana-O-GA).

Wellness and tempering procedures are performed depending on the severity of developmental disorders.

An adequate prevention of rickets and anemia is necessary, development of an individual vaccination calendar.

Premature babies are at risk for morbidity, infant mortality and childhood disability, since irreversible changes in the central nervous system, often combined with congenital malformations, are not ruled out.

Vaccinations are carried out on an individual schedule, depending on the state of health. Most premature babies do not receive the BCG vaccine in the maternity hospital. The issue of initiating vaccination is decided strictly individually, starting at 2 months of age. As a rule, premature babies receive BCG (or BCG-M) vaccine after 6 months due to perinatal CNS lesions and frequent anemia development; subsequent vaccinations, depending on the health of the child, are carried out in a complex (polio vaccine + ADS-M) or separately; Pertussis component (DTP vaccine) in premature infants is used extremely rarely due to the greatest reactogenicity. The first inoculation - BCG, as a rule, is carried out when the body weight reaches 2200 g. With severe CNS lesions, the vaccinations are postponed to 6 months.

The pediatrician determines the time of onset of vaccination with the neuropathologist, taking into account the risk of allergic reactions, assess the usefulness of the immune response. Immunizations for children with altered reactivity are often carried out under the guise of antihistamines.

At all stages of monitoring a premature baby, an active joint work of the doctor and parents is necessary. In the first days and weeks of a newborn's life, the mother, as a rule, needs psychotherapeutic correction, removal of postpartum stress.

The doctor of the children's polyclinic and the health nurse supervise the conditions of the child's home life, the timeliness of medical interventions (visits to specialists, tests, inoculations sessions on stimulating psychoemotional and speech development.For rehabilitation, physical methods are important: various massage, gymnastics, water exercises, dry immersion, music therapy, aromatherapy.

Appropriate sparing home environment and regular classes with parents, sensory stimulation (toys, lullabies), music therapy, elementary skills training are essential for the full development of premature babies.

To control the house in the child's family issue scales. Calculation of food is carried out 1 time in 2 weeks. Patronage of a doctor and a nurse on an individual schedule during the first month, and then depending on the state of health carried out at home or in a clinic.