Types of abnormalities of labor

For the successful development of scientific and practical obstetrics, it is of fundamental importance to elucidate the causes of anomalies of labor and the most reasonable pathogenetic treatment.

In the general concept of anomalies of labor activity include the following types of pathology of contractile activity of the uterus and abdominal press in the process of childbirth:

• weakness of contractile activity of the uterus - primary, secondary, universal;
• weakness of exertion - primary, secondary, universal;
• discoordination of labor;
• hyperdynamic labor activity.

One of the complete systematization of the primary and secondary weakness of labor activity is given in the classification of SM Becker.

Classification of anomalies of labor activity, depending on the period of their appearance:

• latent phase (preparatory period according to E. Friedman);
• active phase (the period of cervical dilatation by Friedman);
• II period of labor (pelvic period according to Fridman).

To the latent phase, when preparations for significant anatomical changes occur later in the cervix, they include only one type of anomaly of labor, namely, a protracted latent phase.

To the anomalies of the active phase of childbirth, characterized by perturbations of the processes of opening the cervix, include:

• protracted active phase of disclosure;
• secondary cervical dilatation stop;
• a prolonged deceleration phase.

The anomalies of the II period of childbirth include:

• impossibility of lowering the presenting part of the fruit;
• slow down of the fetal part;
• stopping the lowering of the fetus.

Finally, there is an anomaly that is characterized by excessive labor activity (rapid delivery). All eight types of abnormalities of labor are presented below.

Period of childbirth	Anomalies
Latent phase	Prolonged latency phase
Active phase	Prolonged active phase of cervical dilatation
	Secondary cervical expansion stop
	Continuous deceleration phase
II period of childbirth	Impossibility of lowering the presenting part of the fetus
	Delayed lowering of the presenting part of the fetus
	Stopping the lower part of the fetus
All periods	Rapid birth

Recognition of these abnormalities does not present difficulties if the obstetrician uses the graphic analysis of labor (partogram). To do this, the cervical opening and lowering of the presenting part of the fetus are marked on the ordinate axis, and the time (in hours) on the abscissa axis. Diagnosis of anomalies of labor without a partograph is inaccurate, and often leads to errors.

Most of the modern knowledge about labor and its anomalies are related to the work of Emanuel A. Friedman. Since 1954, he published the results of clinical studies related to labor; Thus, scientific work was gradually created, which remains unquestionably valuable both in its breadth and in its conclusions. Friedman gave a scientific justification for the clinical evaluation of labor and made the mechanism of labor and its anomalies quite understandable. The basic information is presented in E. Friedman's monograph: "Childbirth: Clinical Evaluation and Management" (1978) (Emanuel A. Friedman, Labor Clinical, evaluation and management Second edition, New York, 1978). At the end of the monograph the author cites over 20 books reflecting in the literature various types of abnormalities of labor.

Classification of the causes of weakness of labor

Causes of primary weakness of labor.

A. Anatomico-functional insufficiency of the neuromuscular apparatus of the uterus:

1. overgrowth of the uterus;
2. birth injury to the uterus;
3. surgical trauma of the uterus;
4. tumors of the uterus;
5. chronic inflammatory changes in the tissues of the uterus.

B. Hormonal insufficiency.

B. Acute general febrile illness.

D. Common chronic diseases.

E. Other reasons:

1. decreased excitability of nerve centers;
2. the influence of psychogenic factors;
3. reflex weakness of labor activity;
4. avitaminosis.

Causes of secondary weakness of labor.

A. The causes of the onset of primary weakness.

B. Functional failure of the abdominal press.

B. Fatigue of the mother in childbirth.

D. Incorrect delivery:

1. untimely opening of the bladder;
2. infringement of a neck of a neck of a uterus;
3. untimely recognition of the narrow pelvis, incorrect insertion of the head or position of the fetus;
4. inept anesthetization of labor.

D. Relative obstructions from the pelvic and soft tissues of the birth canal:

1. anatomical narrowing of the pelvis;
2. stiffness of the cervical tissue;
3. cicatrical changes in the soft tissues of the birth canal.

E. Different reasons:

1. compression of the intestinal loops;
2. Inept use of rhythm-stimulating agents.

Classification of anomalies of labor (Yakovlev II, 1961)

The nature of the contractions of the uterus.

Hypertonus: convulsive (spasmodic) contraction of the musculature of the uterus:

• with a complete spasm of the musculature of the uterus - tetany (0.05%);
• partial spasm of the musculature of the uterus in the region of the external throat at the beginning of the first stage of labor; the lower segment of the uterus at the end of I and at the beginning of the II period of labor (0.4%).

Normotonus:

• uncoordinated, asymmetric uterine contractions in different parts of the uterus, followed by cessation of contractile activity, so-called segmental contractions (0.47%);
• rhythmic, coordinated, symmetrical contractions of the uterus (90%);
• normal contractions of the uterus, followed by weakness of labor, the so-called secondary weakness of labor.

Hypotonus, or true inertness of the uterus, the so-called primary weakness of labor:

• with a very slow increase in the intensity of labor (1.84%);
• without a pronounced tendency to increase the intensity of labor during the entire period of labor (4.78%).

Of the indicators characterizing the state of the pregnant and uterus, the main importance is the tone and excitability. A greater number of parturient women in the etiopathogenesis of violations of contractile activity of the uterus (weakening or complete cessation of fights or disorganization of the latter) is not the fatigue of smooth muscles, but the disorders of the nervous system. In some cases, vegetative-dysfunctional disorders act on the foreground, while in others - neurotic manifestations that cause a disorder of the contractile activity of the uterus. The tone is a biophysical state of the smooth muscles of the uterus, one of the elements of contractile activity, which performs its function due to the elastic elastic properties of smooth muscles. The tone characterizes the working readiness of the body to be active. Due to the tone of the uterus, it is possible for a long time to maintain the condition necessary for the performance of certain functions. Practically distinguish normotonus, hypo- and hypertonus. Opening of the throat, ie, the phenomenon of retraction, depends, first, on the movement of muscle fibers, the angle of inclination of which becomes steeper, which was shown back in 1911 by N. 3. Ivanov.

In this case, if the overall rest tone of the uterus is low, then before the contraction occurs, the walls of the uterus should gradually come to a state of tension. If the rest tone is high, the slightest contraction of the motor part of the uterus will be reflected on the neck, the fibers of which tense and cause the opening.

So, the value of the initial high tone of the uterus consists in the rapid transfer of the force of uterine contractions of the motor part of the uterus to the pharynx, and the opening of the latter occurs quickly. Another meaning of tonus is to maintain the cervical dilatation at the achieved level. It can be assumed that a moderately high tone is a favorable moment for the rapid opening and rapid flow of labor.

On the other hand, an excessively high uterine tone can lead to complications described by Phillips (1938) in the form of birth pains in the absence of labor and Lorand (1938) under the name of "spastic weakness of labor". Between the rest tone and the amplitude of abbreviations for Wolf, there is a direct relationship - with an increase in the tone of rest, the amplitude of contractions decreases. Therefore, the magnitude of the contraction amplitude does not affect the course of labor if there is sufficient tonus.

Classification of abnormalities of labor [Caldeyro-Barcia, 1958]

The author distinguishes the following anomalies of labor.

1. Quantitative abnormalities of uterine contractions. In this group of mothers, the waves of uterine contractions are of normal quality, that is, they have normal coordination with a "triple descending gradient".
   • Hyperactivity. The uterus is considered hyperactive when its contractions have an abnormally high intensity (above 50 mm Hg). Or abnormally high frequency (more than 5 reductions per 10 min), i.e. When the activity of the uterus is a product of intensity and frequency - higher than 250 mm Hg. Art. For 10 minutes in units of Montevideo. Abnormally high frequency of contractions in the works of foreign authors was called tahisistolia, it leads to a special type of hypertensive uterus.
   • Hypoactivity. The uterus is considered hypoactive when the contractions have an abnormally low intensity (below 30 mm Hg) or an abnormally low frequency (less than 2 contractions within 10 min). With uterus activity less than 100 units. Montevideo progress of childbirth is slower than normal. This condition is regarded by clinicians as hypotonic or normotonic weakness of labor activity (inertia of the uterus according to the terminology of foreign authors). The reasons for the hypoactivity of the uterus are still not well known.
2. Quality abnormalities of uterine contraction.
   • Inversion of gradients can be general, affecting all three components: intensity, duration, propagation of the triple descending gradient. In this case, the contraction wave begins at the bottom of the uterus and spreads upward - the ascending waves. They are stronger and last longer in the lower part of the uterus than in the upper and they are completely ineffective for the expansion of the cervix. In some cases, only one or two of the three components are reversible - a partial inversion.
   • Uncoordinated motherhood is observed in those parturient women whose contraction wave does not spread throughout the uterus (generalized form), but remains localized in a certain part of the uterus. Caldeyro-Barcia distinguishes between two degrees of uncoordinated uterine contractions. This is due to the fact that the uterus, according to the author, is functionally divided into numerous zones, which shrink independently and asynchronously.

Uterine uncoordination is characterized by an increased tone of the uterus from 13 to 18 mm Hg. St., against which small, uneven abbreviations having a high frequency are layered. This so-called uterine fibrillation is also known under the name "hypertension with hypysystole", "hypertonic form of weakness of labor activity", "essential hypertension". B. Hypertension. Hypertension of the uterus, when the tone of the uterus is above 12 mm Hg. Art. This anomaly of labor is more often observed in complicated births and is very dangerous for the fetus. The quantitative classification of hypertension is the following - a weak hypertonus - from 12 to 20 mm Hg. St, moderate - from 20 to 30 mm Hg. St., strong - more than 30 mm Hg. Art. It is noted even up to 60 mm Hg. Art.

The causes of hypertonia can be 4 completely different factors:

• excessive stretching of the uterus (polyhydramnios), which increases its tone;
• uncoordinated uterine contractions;
• tahisystole of the uterus, when the frequency of fights exceeds the upper limit - 5 reductions within 10 min, and the tone of the uterus rises above 12 mm Hg. Art. At a contraction rate of 7 for 10 min, there is an increase in tone to 17 mm Hg. Art. Tahisystole is very dangerous for the fetus, as the maternal blood flow through the placenta greatly decreases, causing asphyxia in the fetus and a decrease in the intensity of the contractions of the uterus;
• an increase in the "basic tone", the so-called "essential hypertension."

Hypotension of the uterus, when the uterine tone is below 8 mm Hg. Art. Caldeyro-Barcia believes that the hypotension in labor is very rare and absolutely safe. Hypotoneus of the uterus is usually associated with hypoactivity of the uterus and leads to a slowed flow of labor.

3. Cardiac dystocia.
   • Passive cervical dystocia due to cervical fibrosis, cervical atresia, etc.
   • Active dystocia of the cervix is formed when a triple gradient descending gradient is violated (inversion of gradients), leading to spasm of the internal pharynx. It has been shown that, even with normal births, the lower part of the uterus contractions exert a great pressure on the largest circumference of the fetal head, and with the "spastic" uterus this pressure is much higher and the expansion of the cervix is thus slowed down.

Reynolds (1965) described the patterns of contractile activity of the uterus (hysterogram) necessary for the successful disclosure of the cervix, and introduced the concept of the "triple descending gradient of the uterus" in 1948. In this concept the author puts the following idea: a decrease in the physiological activity of contractions with functional components - and the duration of contractions from the bottom to the lower segment of the uterus. In his monograph the author cites hysterogram samples in preterm birth, when all three levels (bottom, body, lower segment of the uterus) were active, especially the lower segment of the uterus, and the body gave the most irregular activity. With the so-called "false births" (in our terminology - the pathological preliminary period, according to E. Friedman - the preparatory period), the author noted strong contractions in the uterus, regardless of the location of the sensors on the abdominal wall. There is a strong activity of the uterus in the area of its lower segment. There is also a second type of contraction in this pathology, when the lower segment was not active, and there were the most severe contractions in the area of the uterine body and the duration of these contractions in it equaled or exceeded the contraction in the region of the uterine fundus. This condition Reynolds called "physiological contraction ring" ("physiologic contraction ring"). According to the author, prolonged contractions in the area of the lower segment of the uterus - there is a main reason for the lack of progress in labor, that is, there is increased activity and a longer duration of uterine contractions in the lower segment of the uterus.

According to the classification of Mosler (1968), based not only on clinical, but also on hydrodynamic data, among the anomalies of labor activity are distinguished:

1. hypertensive dystocia (hypertensive dystopia) in the presence of a rigid neck;
2. hypotensive dystocia.

In more recent studies, it was shown that abnormal uterine contractions can be identified both in spontaneous labor and during induction and rhythm stimulation by intravenous administration of oxytocin. These abnormalities are usually associated with a decrease in frequency or a decrease in pauses between contractions, followed by the development of acidosis in the fetus.

According to the hysterographic curves, the following classification of anomalies of labor is proposed:

• asymmetry of uterine contraction with lengthening of the relaxation phase;
• more than one peak in the uterine contraction - polysystole (these fights resemble "biceps");
• double abbreviations;
• tahisystole with little or no intervals between contractions;
• tachysystole with uterine hypertension;
• tetanus of the uterus.

Of the modern foreign most complete classifications is the classification of H.Jung (1974), which has not only a clinical but also a physiological basis.

The author calls all forms of pathology of labor activity - dystocia of the uterus. This is explained by the fact that for the normal type of uterine contractions, optimal conditions for the excitation of all myometrium cells with a maximum conduction velocity are necessary at an equally high excitation threshold of simultaneously included refractory periods of the entire musculature of the uterus. These optimal conditions are not given especially at the beginning of the disclosure period, and in the process of childbirth, according to the author's observations in 20-30% of cases without substitution treatment by means regulating the uterine activity.

Ideal would be the division of anomalies of labor for etiological reasons. This experience is the basis for earlier publications on the division of uterine dystopia.

Jung (1967), Caldeyro-Barcia (1958-1960), Cietius (1972) believe that the pathology of labor (dystocia) is etiologically more dependent on the physiological system of excitation and, to a lesser extent, the energy and working system. This was written back in 1957 by I. I. Yakovlev that "a greater number of parturient women in the etiopathogenesis of violations of the contractile activity of the uterus is not the fatigue of smooth muscles, but the disorders of the function of the nervous system."

N. Jung for clinical purposes suggests the following division of pathological forms of contractile activity of the uterus:

1. Weakness of labor.
2. Hyperactive labor is tachysystole in combination with hypertension of the uterus.
3. Hypertensive generic activity:
   • due to passive stretching of the uterus;
   • essential hypertensive labor;
   • secondary hypertensive labor associated with tachysystole.
4. Disruption of coordination:
   • violation of the excitation gradient;
   • Uncoordinated uterine contractions.

At present, only the primary form of weakness in labor is of interest, since the often described secondary weakness of labor was often explained by the depletion of motor activity of the uterus due to the genera object, the state of the birth canal.

With prolonged labor, one can assume fatigue of the body on the basis of depletion of extracellular energy supply or damage to the transport function of electrolytes in the cell membrane with a depletion of the content of extracellular potassium. In such cases, according to Jung, an obstetrician in modern conditions should resort to delivery by cesarean section.

Of the primary forms of weakness of labor activity, often referred to in the foreign literature as "hypoactivity of the uterus" or known as the "inertia of the uterus," the most common type of contraction of the uterus is physiological, which Cietius called "false labor" ). In our terminology, this condition we call a normal or pathological preliminar period.

With this predominant pathological variant of the violation of labor activity, especially at the beginning of the clan act, the matter is primarily concerned with the violation of coordination. Further it is important to note that at the beginning of childbirth, each parental woman can find a transient form of weakness in labor. The weakness of labor activity that lasts longer or is observed during the whole period of the disclosure should be attributed to the disruption of the transport function of electrolytes in the membrane or changes in the cellular metabolism. This also explains the appearance in the literature of reports, taking into account the etiologic approach, the success of the therapy for the weakness of labor activity by intravenous infusion of the potassium solution and, on the other hand, the success of treating the weakness of the labor activity with sparteine (a synonym for pacharcapin-d sparteine hydroiodide; Pushpa, Kishoien, 1968). It should be emphasized that sparteine, as well as some other ganglion blocking agents, has one of the important features, namely, the ability to increase tone and strengthen uterine contractions. In connection with this, sparteine was used to strengthen labor activity in case of weakness of fights and in case of untimely discharge of water, and also with weakness of attempts. The drug is not contraindicated in parturient women suffering from hypertension, as it does not increase blood pressure.

Currently, long-term intravenous infusions of oxytocin or prostaglandins are the method of choosing the treatment of weakness in labor. It is important to emphasize at the same time that a number of authors consider subcutaneous and intramuscular injections of oxytocin as not giving the desired effect, and their appointment is currently not justified, although many CIS clinics use fractional intramuscular injection of oxytocin, especially in combination with quinine.

Hyperactive labor , according to most authors, is observed only when individual contractions of the uterus during childbirth indicate an abnormally high amplitude of labor - more than 50-70 mm Hg. Art. At registration of intrauterine pressure or if the frequency of contractions in the opening period reaches 4 or more within 10 minutes. In this case, the activity of the uterus in 10 minutes reaches 200-250 units. Montevideo. In most cases, there is also an increase in the frequency of fights with an abnormally high amplitude, due to the general dependence of both parameters on the membrane potential of the myometrium cell.

It is extremely important to emphasize that there is an isolated tachysystole without simultaneous increase in amplitude.

Jung points out that the hyperactive contractile activity of the uterus is observed as "Wehenstuim" with a threatening rupture of the uterus according to the data of the old authors. Such situations arise as a result of an endogenous or exogenous overdose of oxytocin. Based on his physiological experiments, the author does not recommend using the concepts known to old authors as "tetanus uteri", since already normal contraction of the uterus is tetanic. What is now understood as "Wehenstuim" (German) or "tetanus uteri" can be explained by the physiologically excitable "Uterus-Kontraktur" through the depolarization of the cell membrane.

Equally, cervical dystopia (Dystokie) with insufficient elasticity of tissues can reflexively lead to hyperactive labor.

Hypertensive generic activity differs, in the first place, by a high tone of rest. This anomaly of labor does not only prolong the course of the birth act, but is extremely dangerous for the fetus. N. Jung points out that the old name "hypertensive weakness of labor contractions" should be avoided, based on pathophysiological reasons. About the cause of hypertensive labor obstetricians currently have more accurate ideas. Hypertensive generic activity begins at a rest tone above 12 mm Hg. Art. Studies on the effect of stretching on the electrical and contractile properties of the myometrium have shown that stretching always causes a decrease in the membrane potential of the cervical and uterine body cells, while the membrane potential of the cells of the uterine body is greater than the membrane potential of the cervical cells for all hormonal states and degrees of extension. Reductions of the uterus are carried out in the body when the mechanisms of self-regulation and the regulatory influence of the autonomic nervous system interact. Self-regulatory mechanisms include maintaining optimal excitability, optimal level of polarization of smooth muscle cells and their optimal contractility. The main elements of them are the level of hormonal saturation and the degree of uterine stretching. The membrane is one of the most important parts of the regulatory chain: the sex hormones - the excitable membrane - the contractile elements of the myometrium cells. In addition, it is known from physiological studies that the stretching of the fibers leads to a decrease in the membrane potential and, thereby, to a violation of the ion exchange process upon excitation.

Often, on the basis of a high rest tone, various abbreviations of smaller amplitudes are associated with disturbances in the rhythm of the order of contractions. The continued stretching of the myometrium, in addition, helps to lower the threshold and increase excitability. Therefore, it is not accidental that a number of authors administer amniocentesis with amniocentesis with the excretion of 1-2 l of amniotic fluid in the course of pregnancy, very slowly, during 6-12 h and with the subsequent administration of beta-adrenomimetic agents. By this medical measure, the authors achieved a noticeable decrease in the tone of rest.

Studies have shown that the reaction of stretched human myometrium to the dilation pulse is the basis for synchronizing the contractile activity of the smooth muscle cells of the myometrium in childbirth. The main role here is played by the mechanoreceptor properties of smooth muscle cells, which react to any impulse of extensor stress with an increase in tension. The increase in voltage is proportional to the tension force. By birth, connective tissue is about 50% of the volume of the myometrium. It was revealed that the mechanoreceptor properties of the myometrium are due not only to the response of smooth muscle cells to the impulse of pre-growth, but to a greater extent depend on the elastic properties of the connective tissue carcass of the uterus.

Essential hypertensive labor is an active form of muscular hypertension of the uterus and such an anomaly of labor can soon lead to a decrease in the blood supply to the uterus and thus represents a fetus-dangerous form of an anomaly of labor. Another conclusion is important from this situation. Long-lasting increased tone of the uterus causes miometralnye metabolic disorders, leading to painful contractions of the uterus in pregnant and parturient women.

The result of essential hypertensive labor can be a premature detachment of the normally located placenta, most often observed in autonomic dysfunction. In addition, essential hypertension of the uterus can be caused by the reflex release of endogenous oxytocin or reflex increase in tone based on the Lindgren and Smyth reflex "head-neck" reflex. According to the described reflex, increased irritation for stretching the cervix through neurogenic afferentation and through paraventricular nuclei and the neurohypophysis may lead to an increased release of oxytocin.

Secondary hypertension of the uterus is caused by tachysystole. The uterus, due to the early onset of a new contraction at a high frequency, does not have time for complete relaxation to ensure a normal rest tone. A similar picture can be observed in uncoordinated battles, because the earlier the phase of relaxation of the individual contraction from subsequent contractions is interrupted, the higher will be the forced secondary level of tonus. This does not mean that the height of the tone is determined by the frequency of fights. Physiological experiments Jung, clinical and hysterographic data of our studies speak against the exclusive combination of secondary hypertonia through dependence on the frequency of fights.

Violations of coordination. To effectively disclose the cervix and a successful completion of labor, a contraction wave with complete coordination of the various parts of the uterus is needed relative to the time of onset of contraction and a contraction of all fibers of the myometrium. Normal labor is performed at the maximum intensity and duration of contractions in the womb, the so-called "triple descending gradient" of uterine contractions by Reynolds, Caldeyro-Baicia. Violations of the same general coordination or individual elements of the "triple descending gradient" can lead to multiple pathological forms of contractions, which, to a greater or lesser extent, can slow the delivery.

There are violations of the excitation gradient in the form of two forms of deviations from the physiological course of contractions of the uterus. The first form of disturbance of the excitation gradient is manifested by the fact that the contractions in the lower segment of the uterus are stronger and longer than in its bottom. Another form, when the waves of contractions have an increasing or increasing spread. In the literature there are statements that both these forms of disturbances in the excitation gradient lead to a delayed opening of the cervix in labor because normal retraction of the musculature in the uterine fundus is disrupted.

Some clinicians, when opening the uterine throat for 6-8 cm, note the so-called secondary weakness of labor activity, linking it with a fairly frequent formation in this disclosure at the same time as contractions of the "cervix" of the cervix. Consider one of the important links in the prenatal rearrangement of the activity of the myometrium, the loss of the blocking function of the cervical muscles. The function of this department of the uterus is of great importance for the maintenance of pregnancy and the physiological course of labor. Many obstetricians the process of losing the inhibitory function of the cervical muscle is called "cervical ripening". NS Baksheev believes that this term is unsuccessful and does not reflect the physiological essence of this process. Lindgren's studies showed that similar uterine hypertension in the lower segment of her ("shutter") is observed in 1-2% of parturient women and can be eliminated in the case of delayed delivery through the use of inhalants from the group of halogenated (fluorotane). Some authors with a similar obstetric situation and disclosure of uterine pharynx at 8 cm or more recommend against a background of barbiturate-fluorotane (halothane) anesthesia finger enlargement of the uterus of the uterus with subsequent delivery in the operative way - vacuum extraction of the fetus. It is equally important to emphasize the great complexity of post-delivery of a correct diagnosis by the obstetrician in determining the violation of the gradient of contractions, since even the use of internal hysterography with the determination of the value of intrapapic pressure in this obstetric situation is not indicative.

Undoubtedly, special importance in the pathological forms of labor contractions, especially at the beginning of the period of disclosure, have disabilities coordination fights.

With normal delivery, the wave of contractions spreads, covering all the uterus sections from the "pace-maker" (pacemaker), which is mainly located in the left tubular corner of the uterus bottom down across the uterus. There are, however, typical disturbances in excitation conditions and local differences in excitability, which result in independent cuts in different parts of the uterus both in place and in time. At the same time, some abbreviations may come from the pacemaker, prevailing in the left trumpet corner. However, they can be detected due to numerous potentially excitable myometrium foci in any other parts of the myometrium.

When explaining a variety of clinical and hysterographic patterns, it is necessary to know that a violation of the coordination of uterine contractions can occur with the participation of two different centers of excitement. All other variants of the violation of coordination should be considered between the form described above and independent many excitation and reduction centers. At the same time, induced bioelectric activity in 60% of cases is accompanied by local contraction, and in 40 % is distributed as a pacemaker type.

This form is clinically manifested as very frequent contractions with small local amplitudes. In most uncoordinated centers, labor pains are referred to by some authors as "muskel-flimraern". The normal progress of labor in the event of a lack of coordination is known to be largely impaired. However, clinicians are well aware of the cases when quite often a woman without regulatory therapy spontaneously gives birth. In Jung's work a hysterogram is given, where the picture is shown between the main rhythm of the fights and the subordinate, the sideline rhythm from the other center of excitement. In this case, excitation from the primary primary rhythm passes into the refractory phase of the secondary rhythm. With a detailed examination of hysterographic patterns, one can see that the main rhythm passes in parallel with the intervals of reduction of the side rhythm. It is clear that such a course of labor with the optimal frequency of fights and their amplitudes, even in the presence of smaller rhythm disturbances, can give a picture of the "normal" period of unfoldment. That is why in recent years the issue of introducing cardiomonitor observation and hysterographic observation in the process of normal and especially complicated births has been widely discussed in clinical obstetrical practice.

Causes of violations of contractile activity of the uterus can be:

• excessive neuropsychic tension, negative emotions;
• inadequacy of neurohumoral mechanisms of regulation of labor activity due to acute and chronic infectious diseases transferred, diseases of the nervous system, disorders of fat metabolism;
• anomalies of development and tumors of the uterus (saddle, horny, septum in the uterus, uterine myoma, etc.);
• pathological changes in the cervix and uterus;
• presence of a mechanical obstacle for fetal progression (narrow pelvis, tumors, etc.);
• polyhydramnios, multiple pregnancy, water scarcity;
• a premature pregnancy;
• irrational use of uterotonic drugs.

To the group of pregnant women of "high risk" of development of anomalies of labor activity it is necessary to refer patients with:

• frequent acute infectious diseases in childhood and adulthood;
• chronic infectious-allergic diseases (chronic tonsillitis, pyelonephritis, etc.);
• late and early onset of menarche;
• violations of menstrual function;
• general and genital infantilism;
• impaired generative function (infertility in history);
• having a history of abortion;
• inflammatory diseases of the genitals;
• endocrinopathies, disorders of fat metabolism (especially obesity III-IV degree);
• complicated by the course of previous births (anomalies of labor, etc.);
• complicated by the current pregnancy (the threat of interruption, toxicosis, frequent intercurrent diseases);
• bottom location of the placenta;
• the age of the first-born to 19 and over 30;
• lack of signs of a pregnant woman's body readiness for childbirth (immaturity of the cervix, negative oxytocin test, etc.).

Classification of anomalies of labor activity [Chernukha EA et al., 1990]

1. Pathological preliminar period.
2. Weakness of labor (hypoactivity or inertness of the uterus):
   • primary;
   • secondary;
   • weakness of attempts (primary, secondary).
3. Excessive labor activity (uterine hyperactivity).
4. Coordinated generic activities:
   • discoordination;
   • hypertension of the lower segment of the uterus (inverse gradient);
   • circular dystocia (contraction ring);
   • convulsive contractions (tetany of the uterus).