Oxygen starvation of the fetus during pregnancy and childbirth: how to determine what is dangerous

Oxygen starvation of the fetus is a lack of oxygen for a child who is in utero. The causes of this condition can be many, as well as the consequences. It is very important to know the main risk factors for this pathology in order to control all manifestations and symptoms and correct them in time.

[1],

Epidemiology

Statistics of the distribution of oxygen starvation suggests that this pathology occurs in more than 40% of newborn babies. Complications of oxygen starvation can occur immediately after birth in the form of asphyxia, which happens in 89% of children. In the future this can cause the death of a newborn. As for chronic hypoxia, in 30% of congenital malformations in a baby, it is one of the main etiological factors. In premature infants, oxygen starvation is very common and 10% of children can be fatal.

[2], [3],

Causes of the oxygen starvation of the fetus

The main causes of oxygen starvation of the fetus can be divided into several groups.

1. The conditions and diseases of the mother, which affect the supply of the fetus with oxygen:
   • blood loss, iron deficiency anemia in the mother, which causes a lack of oxygen due to a deficiency of the hemoglobin of the mother's blood;
   • cardiovascular pathologies in the stage of decompensation in pregnant women;
   • pathology of the respiratory system, which are accompanied by a decrease in oxygen levels in tissues due to insufficient intake (mild hypoplasia in the mother, tuberculosis, chronic lung disease);
   • taking medications or drugs;
   • HIV infection, syphilis, chronic infectious processes of internal organs.
2. Disorder of intrauterine gas exchange:
   • pathology of the umbilical cord with a violation of its normal function - nodes, cord with the umbilical cord;
   • premature aging of the placenta;
   • pathology of placenta previa;
   • fetoplacental insufficiency against the background of diseases in the mother;
   • pathology in childbirth, which lead to a prolonged fetal position in the birth canal or premature detachment of the placenta.
3. Conditions from the side of the baby that can affect the delivery of oxygen.
   • congenital malformations of the nervous system (hydrocephalus, hernia of the brain)
   • critical congenital heart or lung defects;
   • intraventricular hemorrhage;
   • intrauterine infections - herpetic, cytomegalovirus infection, toxoplasmosis;
4. Direct damage to the respiratory tract with a violation of their patency or with serious impairment of their function.
   • meconial aspiration in childbirth;
   • tracheal hypoplasia or fusion of the respiratory tract with the esophagus, other congenital malformations of the respiratory tube.
5. It should be noted that fetoplacental insufficiency is the leading cause of intrauterine hypoxia.

[4]

Risk factors

Risk factors can be identified, based on the following reasons:

1. any pathology of pregnancy with toxicosis, which can lead to a violation of the placental circulation;
2. extragenital diseases of the mother in a state of decompensation;
3. pathological conditions in childbirth lead to intranatal oxygen starvation.

[5], [6]

Pathogenesis

The pathogenesis of the development of oxygen starvation of the fetus depends on the following factors:

1. The oxygen and carbon dioxide content of the mother's blood.
2. The state of uterine and uterine-placental blood circulation.
3. The state of the fetal circulation.

The inadequacy of one or more of these factors leads to a number of compensatory reactions:

1. Increase in the rate of placental blood flow. This helps for a while to compensate for the lack of oxygen that occurs.
2. Hyperplasia of the placenta.
3. Increased capillary fetal area.
4. Increased fetal blood flow.

Oxygen deficiency is an ascending factor of pathogenesis. But then everything depends on the duration of the lack of oxygen. If the shortage is temporary, then the increase in blood flow and other compensatory mechanisms is sufficient to normalize the blood flow for a while. Such an acute oxygen deficiency can pass unnoticed for the fetus.

If the oxygen deficiency is moderate, but long-term, then the fetus gradually adapts to it.

First of all, there is an increase in the processes of tissue respiration, anaerobic glycolysis, erythropoiesis, the function of the adrenal cortex is activated. The cardiovascular system reacts with redistribution of blood with the predominant blood supply of vital organs - the so-called "centralization of blood circulation" (brain, heart). This slows the capillary blood flow of the parenchymal organs. Hypoxia of muscles and internal organs leads to the accumulation of lactate and the emergence of metabolic acidosis.

Prolonged and severe hypoxia causes failure of compensation mechanisms (depletion of the adrenal cortex can lead to arterial hypotension and subsequently to shock).

Metabolic acidosis leads to an increase in the permeability of the vascular wall, which together with a decrease in blood flow and an increase in concentration leads to a sludge effect and microthrombosis. There are diapedemic hemorrhages (point and large in size), cerebral edema, hypovolemia, impaired function of all organs and systems.

The most sensitive to the effect of hypoxia is the central nervous system, where the defense mechanisms of anaerobic glycolysis are most weakly expressed, therefore, hypoxia develops earlier and more intensively. Disruption of the metabolism of ions, the accumulation of toxic products causes the destruction of cell components, their necrosis and death.

Two main processes are developing pathophysiologically: hemorrhagic infarction and development of ischemia (leukomalacia).

The final result depends on the severity and duration of hypoxia, as well as on the maturity of the fetus and newborn. The less maturity of the child - the greater the damage to the body. A significant role is played by traumatic factors during labor, which increase hemodynamic disorders. Hypoxia, even physiological births are traumatic.

Acute hypoxia, which begins in childbirth, differs from chronic. Due to the transience of this form and pathophysiological processes, the immediate role here is played by immediate reflex reactions of the cardiovascular system with minimal metabolic disturbances. However, when the child is immature, the effect of numerous unfavorable antenatal factors, prolonged anoxia at a certain stage, there is a disruption of protective reactions and a sharp drop in peripheral pressure. Collapse, which develops, is accompanied by all pathophysiological reactions and with chronic hypoxia leads to hypovolemia.

[7], [8], [9], [10], [11]

Symptoms of the oxygen starvation of the fetus

Symptoms of oxygen starvation of the fetus appear even during pregnancy and childbirth and the main manifestations of this are as follows:

1. From the palpitation of the fetus - acceleration, slowing down, and then arrhythmia.
2. The deafness of his heart tones.
3. Departure of meconium (admixture of meconium in the amniotic fluid).
4. Strengthening, and then slowing down the fetal movements.

In the case of diagnosis of intrauterine hypoxia, obstetrician-gynecologists should correctly determine the tactics of giving birth to reduce the hypoxic and traumatic injury of the child.

Primary determination of the severity of hypoxia and asphyxia of the newborn is performed by all newborn babies according to the special criteria of the Apgar scale. Evaluation is carried out at the first and fifth minutes of a child's life and allows to assess the degree of adaptation of a newborn immediately after birth. This also makes it possible to suspect the presence of symptoms of oxygen starvation.

The first minute determines the severity of intrauterine hypoxic damage to the fetus.

The fifth minute determines the effectiveness of resuscitation and the severity of the condition of the newborn. If necessary, such an evaluation is carried out at the tenth and fifteenth minutes.

The tenth minute determines the effectiveness of intensive therapy, depending on the adaptive mechanisms of the newborn's body.

The fifteenth minute determines the final result and the prognosis of hypoxia.

So the primary assessment of the child's condition allows you to identify those children who need emergency care.

Given that violations in the oxygen starvation of the fetus involve the involvement of the cerebral vessels, cerebrospinal fluid, then there is a violation of hemolytic dysfunction. This period is valid only in the first 7-10 days of a child's life. Later, with the preservation of clinical manifestations of hypoxia, when the damage to nerve cells comes to the fore in the pathogenesis, the term "ante, intra, perinatal CNS damage to hypoxic genesis" is used. All this affects the appearance of symptoms not only in the first minutes and days of a child's life, but also for a month.

Nerve cells are the first to suffer in conditions of oxygen starvation of the fetus. Therefore, the first signs may show pronounced neurological disorders. This is most often characterized by brain hypoxia, which leads to ischemia of certain areas of the cerebral cortex. This is manifested by a syndrome of hyperexcitability or oppression of the child.

Symptoms that are typical for the increased excitability of a child may occur after several hours after birth. Symptoms that mom may notice are different from those that a doctor may notice. The first signs can be in the form of frequent shrill cries of the child, the sleep period of such children does not take more than twenty to thirty minutes. The baby can shake his chin, there may be a tremor of hands and feet when he cries. The oppression syndrome has slightly opposite signs - the child often sleeps, his muscle tone is lowered, he lies without active movements with arms and legs. These symptoms indicate an oxygen starvation of the fetus, which is acute or chronically developing and affects the central nervous system. But with the defeat of the central nervous system on the background of oxygen deficiency of the fetus, there may be other symptoms.

The convulsive syndrome can also be observed in the form of common tonic-clonic seizures, and in the form of local contractions of muscle groups. Moreover, often in newborns, the equivalent of convulsions is spasm of the muscular musculature of the face with various facial expressions in the form of a smile, unmotivated sucking, or protruding the tongue.

Hypertension-hydrocephalic syndrome is accompanied by increased intracranial pressure. Clinically, this is accompanied by the bulging of the fontanelle, the divergence of the cranial sutures with the increase in the child's head in volume. It can develop against this background nystagmus, strabismus, convulsive alertness.

The central nervous system is the main organ that suffers in the oxygen starvation of the fetus during childbirth. After all, an acute lack of oxygen develops, which causes such symptoms. Oxygen starvation of the fetus during pregnancy, which lasts a long time, affects completely all the organs of the baby. In this case, the processes of tissue formation, as well as their growth, may be disrupted. After birth, this can manifest as congenital malformations of internal organs. They can be from minor - in the form of a small body weight at birth, to significant - congenital heart disease. All this in the absence of a direct cause can cause complications in the future in a child with health.

Complications and consequences

What is dangerous oxygen starvation of the fetus? If this affects the nervous system, there may be long-term consequences in the form of residual cysts in the brain. This may not affect the health of the child, but there may be a violation of the cognitive abilities of the child in the form of poor memory, a backlog in school. If the lesions were more serious, then the impaired motor activity of the child may develop as a decrease in muscle tone or paralysis. Complications of oxygen starvation can be severe if this condition has developed acutely during childbirth. This is accompanied by acute asphyxia of the fetus and the baby is breathing poorly and a normal rhythm of breathing and cardiac activity can not be established. It threatens even death

Diagnostics of the oxygen starvation of the fetus

Diagnosis of oxygen starvation of the fetus should be as early as possible. This allows to minimize those complications that can develop against this background.

If oxygen starvation was during childbirth or even during pregnancy, then it can be diagnosed right after birth. In the first minute the doctor evaluates the overall condition of the baby, and if he does not close, then immediately the child is taken to the resuscitation table and determines vital indicators - heart rate, respiration rate, skin color, reaction to stimuli. At the same time, if any of the indicators decreases, immediately diagnose acute asphyxia, as an external manifestation of oxygen starvation of the fetus.

But if the child was born without signs of respiratory disorders, the diagnosis of oxygen starvation can already be carried out while examining the child already in the ward during the first twenty-four hours after birth.

With this diagnosis, the doctor carefully examines the newborn for all organs and systems. The general condition of the child can be severe due to neurological symptoms - hyperesthesia, generalized convulsions of a clonic nature. The color of the child's skin can be cyanotic or cyanosis can occur only in the area of the nasolabial triangle. Reflexes: sucking, swallowing, searching, Babkin, Moro - are called, but they can be asymmetrical. Depending on the leading syndrome, there may be hyperreflexia or hyporeflexia. The configuration of the head can change even with little expressed hydrocephalic syndrome. Also, the sagittal suture may diverge at the same time. Turgor tissues can be lowered, there may also be muscle hypotension in the syndrome of oppression or a pronounced hypertonia in the syndrome of hyperexcitability.  

It is necessary to conduct diagnostics with evaluation of heart sounds. Heart activity, as a rule, is rhythmic, but tones are often weakened. All other systems are normal. Such violations of the general state, tone, reflexes make it possible to assume that there is a lesion of the central nervous system against the background of the oxygenated fasting of the fetus. In this case, additional diagnostic methods are required.

Analyzes do not give any specific changes. Instrumental diagnostics is considered more informative. All neonates with hypoxia are given neurosonography. Neurosonography is an ultrasound method of brain imaging (visualization), which allows you to assess the state of brain tissue, cerebrospinal fluid through a large fontanel. Neurosonogram describes the macrostructure and echogenicity of brain tissue, the size and shape of the cerebrospinal fluid spaces, resulting in the identification of foci of leukomalacia, intra- or periventricular hemorrhages, expansion of the ventricular system - ventriculomegaly. Hyperoperogenicity of periventricular zones in the region of anterior and posterior horns of the lateral ventricles, according to neurosonogram, allows one to suspect periventricular leukomalacia as one of the signs of brain damage during fetal oxygen starvation. Hyperogeneity in the subendymal areas and intraventricularly suggests the presence of intraventricular hemorrhage. However, to date it is believed that ultrasound diagnosis can be used only as a screening method for identifying children with suspected intracranial lesions.

The characteristic changes in oxygen starvation make it possible to determine that the hemispheres are symmetrical, the lumen of the lateral ventricles is not changed. This excludes intraventricular hemorrhage immediately. Determination of shadows of different intensity and magnitude, increased echogenicity of periventricular areas in the brain structures - all this indicates a damage to hypoxic genesis. Also, leukomalacia in the ventricular area can be observed with the further formation of cysts that can be observed throughout life.

[12], [13]

Differential diagnosis

Differential diagnosis of oxygen starvation should be carried out at the stage of clinical diagnosis. It is very important to differentiate the neurological symptoms of oxygen starvation with manifestations of intraventricular hemorrhage. Intraventricular hemorrhage, as a rule, is diagnosed in premature babies born with a body weight of less than 1500 g. In contrast, oxygen starvation can be in children with any gestational age and any weight.

The first symptoms of intraventricular hemorrhage are characterized by a clinic of progressive anemia, a decrease in muscle tone, adynamia, bulging of a large fontanel. Other symptoms (ocular, convulsions) are less common, and less pronounced (attacks of apnea, tachi, or bradycardia). Congenital reflexes are depressed. There is a large tremor, which is worse with head movements, and tonic convulsions, which turn into opisthotonus. Often, existing disorders on the part of the organ of vision (wide-open eyes, paresis of the eyes, flabby reaction of the pupils to light), vertical or rotatory nystagmus, oppression of sucking and swallowing. That is, such symptoms other than similar muscle disorders have distinctive features - this is the predominance of local symptoms.

The newborn lies on his side with his head thrown back, often on this side there is a dilated pupil. Such meningeal symptoms are characteristic signs of hemorrhage, in contrast to the manifestations of ischemia against the background of oxygen starvation, when the meningeal symptoms are not expressed.

Lumbar puncture allows you to detect elevated CSF pressure. It is evenly colored in red or pink with a large number of fresh and altered red blood cells.

[14], [15], [16], [17], [18]

Treatment of the oxygen starvation of the fetus

Treatment of oxygen starvation of the fetus is to provide primary care and treatment of acute damage to the nervous system.

Primary treatment for acute manifestations of hypoxia is to provide measures to restore vital indicators in the ABC system:

1. Restoration of air permeability through the oral cavity and the respiratory tube (A - Airway).
2. Artificial ventilation (B - Breath).
3. Indirect cardiac massage (C - Cordial).
4. Correction of metabolic disorders in the completion of the activities of ABC-resuscitation.

All these medical measures should be carried out immediately after birth and every next step is carried out only if the effectiveness of the previous one is assessed. A careful sequence of steps and feedback between them create an algorithm for the behavior of the doctor in asphyxiation. The sequence of this complex of care depends on the severity of hypoxia, the degree of maturity of the baby, the course of the ante- and intranatal period, as well as the effectiveness of the previous treatment, including ante, and intranatal. The main indicators that take into account how the control of the effectiveness of therapeutic measures are skin color, microcirculatory disorders, hypovolemia, heart rate. The presence of one or more pathological signs determines the different tactics of resuscitation.

As for the treatment of oxygen starvation, which caused damage to the nervous system, then they use a complex approach with drugs, vitamins, restorative gymnastics.

If the CNS is diagnosed, treatment begins with resuscitation in the maternity hospital. The treatment of such children ends, as a rule, in conditions of separation of the second stage of nursing preterm or in the department of pathology of newborns.

Treatment activities include:

• stay in a specialized cave with the necessary microclimate and humidity;
• masimalnaya oberegatelny regime (a decrease in the intensity of stimuli, sparing reviews, minimal painful appointments);
• natural feeding (depending on the severity of the condition possible parenteral nutrition, feeding through a probe or from a bottle with the use of expressed breast milk);
• carefully thought-out and expediently limited medicinal therapy (dehydration, anticonvulsant, antihemorrhagic, vaso-strengthening, drugs, normalizing metabolic processes in the nervous tissue and increasing the resistance of the brain to hypoxia).

There are no uniform approaches to prescribing these or those drugs. Only three clinical syndromes (hypertensive-hydrocephalic, convulsive and muscular hypertonus) require the prescription of drugs.

It is recommended to continue natural feeding, observe the regime of the day, constantly stimulate visual-auditory reactions (bright toys, music, singing) and motor skills, especially motor-visual coordination during the first 3 months of life.

Syndrome of increased nervous reflex excitability has the main task of treatment to reduce hypertension, improve nerve conduction. There are following approaches to the treatment of this condition:

1. Phenobarbital is a drug from a group of neuroleptics that acts on the central nervous system by inhibiting the activity of enzyme systems, which reduces the increased nervous excitability in a child against the background of oxygen starvation. The drug also removes convulsive readiness, if the baby has a predisposition to this. Dosage of the drug - 3-4 mg / kg per day for 3 -4 weeks. Side effects can be if the dosing is disturbed in the form of inhibition, drowsiness, decreased reflexes, and breathing disorders. Precautions - you need to carefully combine the drug with other antipsychotics.
2. Magnesia-citral medicine is a compound of 1% solution of Citral 2.0 milliliters, magnesium sulfate 3.0 milliliters, extract from valerian 2.0 milliliters (or without), 10 per cent glucose solution (200 mL). This combination can reduce the increased excitability of the nervous system, as well as control muscle tone and reflexes. Dosage of the drug - 1 teaspoonful 3 times a day. Side effects can be in the form of oppression of consciousness, allergic reactions, so for newborns the drug is used with a clear dosage and extreme caution.
3. Midokalm is a drug used to correct increased muscle tone. It reduces the amount of active acetylcholine, which increases muscle contraction. Due to this action, the expressed hypertonicity decreases and the work of all organs and systems improves. The dosage of the drug is 0.0125-0.025 g / day. The method of application can be intramuscular, dividing the drug into two or three doses. Side effects can be in the form of twitching of certain muscle groups, pronounced hypotension, lethargy.
4. Prozerin is a drug from the group of anticholinesterase drugs. It is used in the treatment of oxygen starvation, which is accompanied by a pronounced syndrome of depression. The drug removes the action of the enzyme cholinesterase, which increases the activity of acetylcholine and improves muscle tone. Dosage of the drug is 0.003 mg / kg IM. Apply no more than ten days to correct the tone and general condition of the child. Side effects can be in the form of convulsive shortening of facial muscles, visual impairment, allergic manifestations.
5. Actovegin from oxygen starvation of the fetus is also used in treatment to improve recovery of damaged areas. The drug refers to the hydrolysates of the protein structure, which penetrates into the ischemic areas and restores the vascular system there. This improves the recovery period. Dosage of the drug at the initial stages of treatment - up to 20 milligrams per day, divided into two doses. Method of application intramuscular. Next, they switch to oral administration of the drug in tablets of 50 milligrams twice a day until the symptomatology decreases. Adverse events - violations of the total blood flow, which can be accompanied by cooling of the limbs.

Such a syndromic approach to treatment allows you to correct the symptoms and improve the prognosis of the child after oxygen starvation. It is very important in the future to use vitamins, physiotherapy treatment. Vitamins that are most often used - B1, B6, ATP at 15-20 per course daily or every other day by intramuscular injection or by injection. Next, they switch to taking oral vitamin preparations during the first month of the baby's life.

From the methods of physiotherapeutic treatment use a general soothing massage, coniferous baths, paraffin applications like "boots". Also used electrophoresis on the cervical and lumbar spine with nicotinic acid, euphyllin.

Alternative treatment in the acute period of oxygen starvation of the fetus is used very rarely. Such cases of the use of herbs or methods of alternative treatment are limited only to the use of these methods in the late recovery period, when there are residual symptoms of certain symptoms.

Homeopathy can also be used to improve nerve conduction, cognitive function. Drugs use a long time, sometimes during the first year of life.

Surgical treatment of this pathology is not used.

Prevention

Prevention of oxygen starvation of the fetus is primarily in the safe pregnancy and bearing a healthy child. For this, any pregnancy should be planned with a thorough examination of the future mother. This allows you to eliminate the risk factors of the mother, which can affect the violation of oxygen delivery or the formation of the placenta.

[19], [20]

Forecast

The prognosis for recovery from oxygen starvation of the fetus is positive, even if there were asphyxiated phenomena after birth. If, within 15 minutes after birth, the Apgar score is 0-2 points, the lethality is 50%, however, in 90% of the survivors, normal neurological development is possible. The prognosis for complete recovery during hypoxic injuries is positive in the case of applying all the methods of treatment, massage and restorative procedures in the first six months of life of the baby.

Oxygen starvation of the fetus is a condition in which the child is in utero or at birth does not receive enough oxygen for the normal development of all organs and systems. The reasons for this state can be many and the consequences can be serious. Therefore, it is very important to prevent such conditions and in time to adjust the state of the child to avoid complications.  

[21], [22], [23], [24]