Discoordination of labor activity: what is it, classification, causes and treatment. Discoordinated labor activity

Discoordinated labor activity is a deviation in the contractile activity of the uterus, characterized by contractions that are uneven in frequency and intensity in different parts of the organ. In this case, the violation of the consistency of abbreviations can be:

• between the bottom and the body of the uterus;
• between the right and left halves of the uterus;
• between the upper and lower part of the uterus;
• between all sections of the uterus.

At the same time, contractions turn out to be ineffective, but at the same time quite painful, and the opening of the cervix of the uterus is delayed in time. Thus, childbirth takes place haphazardly, which is considered a violation of the normal physiological process.

There are three degrees of discoordinated labor activity:

• Grade 1: The tone of the uterus is moderately increased, contractions are either too slow or too fast.
• Grade 2: a spasm of the circular muscles spreads from the internal os to other parts of the uterus, in addition, the woman in labor has various autonomic disorders;
• Grade 3: a prolonged spasm extends to the vagina, which can completely stop labor activity.

Accordingly, the strength of the manifestation of clinical symptoms and the likelihood of complications with the transition to each new degree increase.

Causes of discoordinated labor activity

Although this pathology is not so common (in about two percent of cases), there are quite a few reasons that can provoke it. They can be divided into 4 groups:

• gynecological;
• obstetric;
• external;
• somatic.

Gynecological causes of discoordinated labor activity imply that a woman has any diseases of the reproductive system that manifested itself even before pregnancy (for example, various menstrual irregularities or inflammatory processes in the cervical canal or in the uterus). This also includes numerous deviations in the development of the uterus itself:

• hypoplasia;
• stiffness of the cervix;
• bicornuate uterus;
• separation of the cavity in two (intrauterine septum).

Finally, a past abortion, cauterization of erosion, or any other intervention that left behind a scar or scar can cause discoordinated labor activity.

Obstetric causes, as a rule, make themselves felt during pregnancy or with the onset of childbirth. At risk are women in labor whose age is beyond the framework of a favorable reproductive function - both too young (under 18 years old) and old-bearing women (over 30 years old). The main obstetric factors in the development of discoordinated labor activity:

• placenta previa;
• pelvic presentation of the fetus;
• fetoplacental insufficiency;
• early discharge of amniotic water;
• late gestosis.

The overstretching of the uterus during multiple pregnancy or polyhydramnios, as well as the discrepancy between the size of the fetal head and the parameters of the birth canal, can also play a role. Finally, deviations in the development of the fetus are risk factors:

• immune conflict between mother and child by blood type;
• intrauterine infection;
• malformation of the brain.

The external causes of discoordinated labor activity include errors in the work of obstetricians-gynecologists:

• inaccurate actions during the study;
• stimulation of labor without special need;
• untimely opening of the fetal bladder;
• insufficient or incorrectly selected anesthesia.
And the last group of causes - somatic - includes diseases of the nervous system, anemia, infectious diseases and intoxications that are in the history of the woman in labor.

Symptoms of discoordinated labor activity

Symptoms of this violation of the birth process are differentiated depending on its type. Medicine knows 4 types of discoordinated labor activity:

• general discoordination;
• hypertonicity of the lower segment of the uterus;
• tetanus (tetany) of the uterus;
• circular dystocia of the cervix.

However, with any of the listed types, the following manifestations of a violation of the process of childbearing are noted:

• pain in the lower abdomen, radiating to the sacrum;
• uneven tension of the uterus;
• arrhythmic contractions;
• increased tone of the uterus;
• nausea;
• anxiety state;
• fast fatiguability.

Now consider the symptoms of discoordinated labor activity, depending on its types.

Symptoms of general discoordination:

• protracted course of childbirth;
• irregular contractions;
• the lack of a certain dynamics in the strength and duration of contractions;
• painful sensations.

In this case, the amniotic fluid leaves earlier than expected, and the presenting part of the fetus is above the entrance to the small pelvis or even pressed against it. In this case, there is a threat of fetal hypoxia as a result of impaired placental blood circulation.

Symptoms of hypertonicity of the lower segment of the uterus:

• high intensity of contractions;
• painful sensations;
• insufficient dilatation of the cervix (or no dilatation at all);
• problems in moving through the birth canal of the fetal head.

If the contractions of the body of the uterus are weaker than the contractions of its lower segment, then the reason may lie in the underdevelopment or rigidity of the cervix.

Symptoms of uterine tetanus:

• thickening of the uterus;
• prolonged uterine contractions;
• painful sensations;
• deterioration of the fetus.

Usually, such a condition is provoked by medical interventions, such as turning the fetus, trying to extract it by applying obstetric forceps, and inadequate administration of stimulant drugs.

Symptoms of circulatory dystocia of the cervix:

• protracted course of childbirth;
• contraction of circular muscle fibers in all segments of the uterus, except for the cervix;
• pain in the "constriction" area.

This condition is fraught with hypoxia or fetal asphyxia.

Diagnosis of discoordinated labor activity

Following the complaints of the woman in labor, the doctor conducts an obstetric examination, which, as a rule, shows the unavailability of the birth canal. It is characterized by swelling of the edges of the pharynx of the uterus and their thickening. On palpation of the body of the uterus, uneven tension in its different departments is fixed.

A more complete picture of the condition of a woman and her unborn child is given by cardiotocography. This is a method that combines the principles of doplerometry and phonocardiography. It will characterize in dynamics not only the contractile activity of the uterus, but also the work of the fetal heart, and in some cases its movement. During childbirth, cardiotocography allows you to monitor the development of hypoxia.

Complications of discoordinated labor activity

Discoordinated labor activity is a phenomenon that is dangerous for both the woman in labor and the fetus. The most serious outcomes are:

• intrauterine hypoxia - oxygen starvation of the fetus, which can lead to its death;
• amniotic fluid embolism - the ingress of amniotic fluid into the vessels (and later into the bloodstream), which can cause blood clotting disorders and the formation of blood clots;
• hypotonic bleeding in the first few hours after delivery.

In addition, discoordinated uterine contractions interfere with the normal progression of the fetus. As a result, its articulation may be disturbed, extension of the head or rear view may occur. There is a risk of spinal extension, limb or umbilical cord prolapse.

A woman in labor may experience complications such as swelling of the vagina or cervix, caused by unproductive attempts. In such a situation, the fetal bladder is defective and does not fulfill its function of opening the cervix of the uterus. It has to be opened to avoid increasing pressure on the uterus, which, in turn, can cause premature placental abruption or even rupture of the organ.

Treatment of discoordinated labor activity

The main goal of treatment is to reduce the tone of the uterus. In addition, it is required to relieve pain and spasms. Methods of treatment are also differentiated depending on the type of discoordinated labor activity.

Treatment of general discoordination and hypertonicity involves obstetric anesthesia, the introduction of antispasmodics. Electroanalgesia is best for calming the uterus.

If the doctor is dealing with uterine tetany, then after the introduction of obstetric anesthesia, he uses α-agonists. β-agonists are used in case of circulatory dystocia. By the way, in the latter case, antispasmodics and lidase are absolutely ineffective. The introduction of estrogen here is also undesirable.

As for delivery, it may end naturally, or it may require surgical intervention. If the birth canal is ready for the extraction of the fetus, then obstetric forceps are used. Otherwise, a caesarean section is scheduled.

With any method of treatment, the obstetrician should carry out therapy that prevents fetal hypoxia. If the tragedy did occur, then a fruit-destroying operation is performed. After removing the dead fetus, the separation of the placenta is performed manually. The doctor must certainly examine the uterus in order to avoid ruptures.

Prevention of discoordinated labor activity

To prevent the threat of the development of discoordinated labor activity, first of all, the attentive attitude of the gynecologist who leads the pregnancy in a woman can. Particularly sensitive attitude is required by patients whose pregnancy is difficult. At the same time, expectant mothers should listen to the advice of a doctor so that the birth process goes without complications.

If the patient is at risk (for example, due to age or abnormalities in the development of the uterus), then drug prevention of discoordinated labor can be prescribed to her. However, in addition to drugs, methods of muscle relaxation, the development of control over the muscles, the ability to easily overcome and relieve excitability will also help. Therefore, do not neglect classes for expectant mothers.

• sleep at least 9 hours;
• often walk in the fresh air;
• enough to move (but not overwork);
• eat wholesome food.

During childbirth, the obstetrician's maximum care and adequate anesthesia are required.

Under the discoordination of labor, it is customary to mean the absence of coordinated contractions between the various parts of the uterus: the right and left halves, the upper and lower segments.

The frequency is 1% of the total number of births.

It is proposed to single out the primary discoordination that occurs during pregnancy and from the onset of childbirth, and the secondary discoordination that develops during childbirth.

The main clinical symptoms of primary discoordination of labor activity: pathological preliminary period, lack of biological readiness of the body for childbirth, "immature" cervix, tendency to overmaturity, prenatal outflow of water.

Secondary discoordination develops in childbirth as a result of unresolved primary discoordination or due to irrational management of labor (for example, attempts to activate in the absence of biological readiness for childbirth) or due to obstacles: a flat amniotic sac, a narrow pelvis, cervical myoma. Clinical signs of secondary discoordination: dystocia of the cervix, the formation of a flat fetal bladder, an increase in the basal tone of the myometrium.

Cervical dystocia occurs when there is no process of active relaxation of the circular muscles in the cervical or lower segment. The neck is thick, rigid, poorly extensible, uneven thickening and significant tissue density are observed. During contraction, the density of the neck increases as a result of spastic contraction of the circular muscle fibers.

At stage I of discoordination, there is an overexcitation of the parasympathetic division of the nervous system, which causes simultaneous contraction of the longitudinal and circular muscles. Circular muscles are in a state of hypertonicity. However, the slow opening of the cervix can occur due to a significant tonic tension of the longitudinal muscles at this stage. The basal tone of the uterus is increased. A characteristic feature is the soreness of uterine contractions. The edges of the cervix tighten during contractions.

Stage II of discoordination (spastic) occurs if treatment is not carried out in stage I or with unjustified use of uterotonic drugs. The tone of the longitudinal and circular muscles sharply increases, the basal tone of the uterus is increased, especially in the lower segment. Contractions become spastic, very painful. The woman in labor is excited, restless. Contractions begin in the area of ​​the lower segment (reverse gradient). Fetal heartbeat may be affected. During vaginal examination, the edges of the external pharynx are of uneven density, poorly extensible. During the contraction, contractions of the edges of the cervix are detected (Schikkele's symptom). Fetal complications are caused by impaired uteroplacental circulation.

III stage of discoordination is characterized by severe violations of the contractile activity of the uterus, the development of tetanic contractions in all parts of the uterus, high tone of the myometrium, cervical dystocia. Contractions of different departments are short, arrhythmic, frequent, with small amplitude. They are regarded as fibrillar. With a further increase in the tone of the uterus, contractions disappear, a tetanic state of the longitudinal and circular muscles develops. The woman in labor feels constant dull pain in the lower back and lower abdomen. The fetal heartbeat is deaf, arrhythmic. On vaginal examination, the edges of the pharynx are dense, thick, and rigid.

When choosing corrective therapy for discoordination of labor activity, one should proceed from a number of provisions.

1. Before giving birth through the natural birth canal in case of complex multicomponent dysregulation of the contractile activity of the uterus, including myogenic (the most ancient and strongest in human evolutionary development), it is necessary to make a prognosis of childbirth, providing for outcomes for the mother and fetus.

The prognosis and plan for the management of childbirth are based on the age, history, health status of the woman in labor, the course of pregnancies, the obstetric situation, and the results of assessing the condition of the fetus.

Unfavorable factors include:

Late and young age of the primiparous;

Aggravated obstetric and gynecological history (infertility, induced pregnancy, birth of a sick child with hypoxic, ischemic, hemorrhagic damage to the central nervous system or spinal cord);

The presence of any serious illness, in which a protracted course of childbirth and physical activity is dangerous;

Severe preeclampsia, narrow pelvis, post-term pregnancy, uterine scar;

The development of discoordination of contractions at the very beginning of labor (latent phase);

Untimely discharge of amniotic fluid with an "immature" cervix with a small opening of the uterine os; critical anhydrous interval (10-12 hours);

The formation of a birth tumor with a high-standing head and a small (4-5 cm) opening of the uterine os;

Violation of the normal biomechanism of childbirth;

Chronic hypoxia of the fetus, its too small (less than 2500 g) or large (3800 g or more) sizes that do not correspond to the average gestational age; breech presentation, posterior view, decreased blood flow in the fetus.

2. With all the listed risk factors, it is advisable to choose the method of delivery by caesarean section without attempting corrective therapy.

A woman in labor may experience life-threatening complications: uterine rupture, amniotic fluid embolism, premature detachment of the placenta, extensive ruptures of the birth canal, combined hypotonic and coagulopathic bleeding.

3. In the absence of risk factors or in the presence of contraindications to caesarean section, a multicomponent correction of labor activity is performed.

Rodostimulating therapy with oxytocin, prostaglandins and other drugs that increase the tone and contractile activity of the uterus, with discoordination of labor, is contraindicated.

I degree (dystopia of the uterus). The main components of the treatment of discoordination of labor activity at the I degree of severity are: antispasmodics, anesthetics, tocolytics (?-adrenergic agonists), epidural anesthesia.

Throughout the first and second stages of labor, it is necessary to administer (intravenously and / or intramuscularly) every 3 hours antispasmodic drugs (no-shpa, baralgin, diprofen, gangleron) and analgesic (promedol, morphine-like drugs) action. A 5-10% glucose solution with vitamins is also used (ascorbic acid, vitamin B6, E and A in a daily dosage).

The use of antispasmodics begins with the latent phase of childbirth and ends with the full opening of the uterine os.

Of the most effective methods for eliminating basal uterine hypertonicity, the use of?-adrenergic agonists (partusisten, alupent, bricanil) should be singled out. A therapeutic dose of one of the listed drugs is dissolved in 300 ml or 500 ml of 5% glucose solution or isotonic sodium chloride solution and injected slowly intravenously initially at a rate of 5-8 drops / min, then every 15 minutes the frequency of drops is increased by 5-8, reaching a maximum frequency 35-40 drops / min. After 20-30 minutes, the contractions almost completely stop. There comes a period of rest of uterine activity. Tocolysis is completed 30 minutes after the onset of normalization of uterine tone or termination of labor.

After 30-40 minutes, contractions resume on their own and are of a regular nature.

Indications for tocolysis of the uterus during childbirth are:

Hypertensive dysfunction of the contractile activity of the uterus and its variants;

Rapid and rapid childbirth;

Protracted pathological preliminary period.

With a short pathological preliminary period (no more than a day), you can apply a tocolytic inside once (brikanil 5 mg).

4. In case of discoordination of contractions, it is necessary to eliminate the defective fetal bladder. The fetal membranes must be separated (taking into account the conditions and contraindications for artificial amniotomy).

Amniotomy is performed immediately after intravenous administration of an antispasmodic (no-shpa 4 ml or baralgin 5 ml), so that a decrease in the volume of the uterus occurs against the background of the action of antispasmodics.

5. Due to the fact that anomalies of labor activity are accompanied by a decrease in uterine and uteroplacental blood flow and fetal hypoxia, agents that regulate blood flow are used in childbirth.

These funds include:

Vasodilators (eufillin);

Drugs that normalize microcirculation processes (rheopolyglucin, glucosone-vocaine mixture with agapurine or trental);

Means that improve the absorption of glucose and normalize tissue metabolism (actovegin, cocarboxylase);

Means for the protection of the fetus (seduxen 0.07 mg / kg body weight of the woman in labor).

All drug therapy should be regulated by the hour.

Childbirth is carried out under cardiomonitoring and hysterographic control. Antispasmodics are constantly dripped. The base solution for antispasmodics is a glucosone-vocaine mixture (10% glucose solution and 0.5% novocaine solution in equal proportions) or 5% glucose solution with trental (5 ml), which improve microcirculation and reduce pathological excessive uterine impulses.

In case of untimely discharge of amniotic fluid, antispasmodics should be administered intravenously. When the cervix is ​​4 cm dilated, epidural anesthesia is performed.

6. In the second stage of labor, a perineal incision is necessary to reduce the mechanical impact on the fetal head.

Drug prophylaxis of bleeding is carried out using a single-stage intravenous injection of 1 ml of methylergometrine or syntometrine (0.5 ml of methylerometrine and oxytocin in one syringe).

With the onset of bleeding in the early postpartum period, 1 ml of prostin F2? is injected into the thickness of the uterus (above the uterine os). 150 ml of 40% glucose solution (subcutaneously - 15 IU of insulin), 10 ml of 10% calcium gluconate solution, 15 ml of 5% ascorbic acid solution, 2 ml of ATP and 200 mg of cocarboxylase are poured intravenously with quick drops.

Childbirth with discoordination of contractions should be conducted by an experienced obstetrician-gynecologist (senior physician) together with an anesthesiologist-resuscitator. At the birth of a child, a neonatologist must be present, able to provide the necessary resuscitation assistance.

Control over the course of labor is carried out with constant medical supervision, cardiomonitor recording of the fetal heartbeat and uterine contractions, using external or internal tocography. Registration of contractions is carried out by a stopwatch for 10 minutes of each hour of labor. It is advisable to keep a partogram.

II degree (segmental dystocia of the uterus). Given the adverse effect of segmental dystocia on the fetus and newborn, vaginal delivery is not appropriate.

A caesarean section should be performed in a timely manner.

The most effective is epidural anesthesia.

Epidural anesthesia blocks the Th8-S4 segments of the spinal cord, inhibits the action of oxytocin and PGG2?, has an antispasmodic and analgesic effect, which significantly reduces and sometimes even eliminates the spastic state of the uterus. Seduxen (relanium, fentanyl) acts on the limbic structures of the fetal brain, providing protection from pain and mechanical overload that occurs during hypertensive uterine dysfunction during childbirth.

It is advisable to inject 30 mg of fortral once, which provides an increase in the resistance of the fetus to pain. Fortral is similar in structure and protective effect to the endogenous opiate anti-stress system of the mother and fetus. Therefore, in severe cases of discoordination of labor activity, the use of morphine-like drugs (fortral, lexir, etc.) can protect the mother and fetus from birth shock. The drug is administered once to avoid addiction, do not use large doses and do not prescribe it close to the expected birth of the child, as it depresses the fetal respiratory center.

Particular attention is paid to the management of the second stage of labor. Until the birth of the fetus, intravenous antispasmodics (no-shpa or baralgin) are continued, as there may be a delay in the shoulders of the fetus in the spastically reduced uterine os.

As with other forms of discoordination of labor activity, drug prevention of hypotonic bleeding with the help of methylergometrine is necessary.

With discoordination of the contractile activity of the uterus in the afterbirth and early postpartum period, there is a danger of a large amount of thromboplastic substances entering the uterine and general circulation, which can cause an acutely developed DIC. Therefore, childbirth with hypertensive uterine dysfunction poses a risk of coagulopathic bleeding.

In the event that labor activity has weakened after tocolysis, myometrial tone has returned to normal, contractions are rare, short, cautious labor stimulation with PGE2 preparations (1 mg of prostenon per 500 ml of 5% glucose solution) is started. The rules of rhodostimulation are the same as in the treatment of hypotonic weakness of labor, but it should be carried out with extreme caution, controlling the frequency and duration of contractions with a stopwatch. However, such management of childbirth can be carried out only in cases where it is impossible to perform a caesarean section.

It should be emphasized once again that in case of discoordination of labor activity, it is impossible to use drugs that stimulate the contractile activity of the uterus (oxytocin, PGF2 preparations?). However, in those cases when hyperdynamic labor activity turns into hypodynamic, the uterine tone decreases to values ​​characteristic of weak contractions, careful labor stimulation with PGE2 preparations against the background of epidural anesthesia or intravenous administration of tocolytics is possible.

III degree (spastic total dystocia of the uterus). The basic principle of labor management in total spastic uterine dystocia is to attempt to translate hyperdynamic labor activity into hypotonic weakness of contractions, to reduce the basal tone of the myometrium using tocolysis.

It is necessary to completely remove the general muscular and mental tension, restore autonomic balance, and eliminate constant pain.

A favorable outcome of childbirth can be achieved either by a timely caesarean section, or by adhering to a certain system to eliminate spastic (segmental or total) uterine contraction.

Given the violation of the leading regulatory role of the central nervous system in the development of this type of anomaly of labor, the woman in labor must first of all be given sleep-rest for 2-3 hours. If the fetal bladder is intact, it must be eliminated by amniotomy with the preliminary administration of antispasmodics. The delay in amniotomy exacerbates the negative impact of the flat membranes on discoordinated uterine contractions.

After rest, if labor activity has not returned to normal, acute tocolysis is performed (the technique is described earlier) or epidural anesthesia is performed. Before epidural anesthesia, intravenous administration of crystalloids is carried out in order to adequately prehydrate and prevent the risk of arterial hypotension. If the patient received drugs of tocolytic (?-adrenomimetic) action, adrenaline and its compounds should not be used.

After tocolysis (if labor activity has not resumed and has not returned to normal within 2-3 hours), PGE2 preparations are carefully administered for the purpose of labor stimulation.

The choice of an operative method of delivery is explained by the great difficulties that arise when restoring the normal contractile activity of the uterus with discoordination of labor activity of the III degree of severity.

However, with a late admission of a woman in labor or a belated diagnosis of this type of anomaly in labor, it can be difficult to decide on a caesarean section.

First, the clinical symptoms of autonomic dysfunction (fever, tachycardia, skin flushing, shortness of breath) develop rapidly.

Secondly, there is a violation of the condition of the fetus (hypoxia, asphyxia). With a caesarean section, a dead or dead baby can be removed.

Thirdly, there is often a long anhydrous period, the presence of an acute infection.

The degrees of discoordination of labor activity are varied. Even the true weakness of contractions and attempts can be combined with elements of impaired coordination of uterine contractions. The hyperdynamic nature of contractions becomes hypodynamic and vice versa.

Under the anomalies of the labor forces understand the disorders of the contractile activity of the uterus, leading to a violation of the mechanism of opening the cervix and / or the promotion of the fetus through the birth canal. These disorders can relate to any indicator of contractile activity - tone, intensity, duration, interval, rhythm, frequency and coordination of contractions.

ICD-10 CODE
O62.0 Primary weakness of labor.
O62.1 Secondary weakness of labor
O62.2 Other weakness of labor
O62.3 Rapid labor.
O62.4 Hypertonic, uncoordinated and prolonged uterine contractions.
O62.8 Other disorders of labor
O62.9 Disorder of labor, unspecified

EPIDEMIOLOGY

Anomalies of the contractile activity of the uterus during childbirth occur in 7–20% of women. Weakness of labor activity is noted in 10%, discoordinated labor activity in 1-3% of cases of the total number of births. Literature data indicate that the primary weakness of labor activity is observed in 8-10%, and the secondary - in 2.5% of women in labor. Weakness of labor activity in older primiparas occurs twice as often as in those aged 20 to 25 years. Excessively strong labor activity related to hyperdynamic dysfunction of the contractile activity of the uterus is relatively rare (about 1%).

CLASSIFICATION

The first classification based on the clinical and physiological principle in our country was created in 1969 by I.I. Yakovlev (Table 52-5). Its classification is based on changes in the tone and excitability of the uterus. The author considered three varieties of tonic tension of the uterus during childbirth: normotonus, hypotonicity and hypertonicity.

Table 52-5. Forms of tribal forces according to I.I. Yakovlev (1969)

In modern obstetrics, when developing a classification of anomalies of labor activity, the view of the basal tone of the uterus as an important parameter for assessing its functional state has been preserved.

From a clinical point of view, it is rational to isolate the pathology of uterine contractions before childbirth and during childbirth.

In our country, the following classification of anomalies of the contractile activity of the uterus has been adopted:
· Pathological preliminary period.
Primary weakness of labor activity.
Secondary weakness of labor activity (weakness of attempts as its variant).
Excessively strong labor activity with a rapid and rapid course of childbirth.
Discoordinated labor activity.

ETIOLOGY

Clinical factors that cause the occurrence of anomalies of generic forces can be divided into 5 groups:

obstetric (premature outflow of OB, disproportion between the size of the fetal head and the birth canal, dystrophic and structural changes in the uterus, cervical rigidity, uterine hyperextension due to polyhydramnios, multiple pregnancy and large fetus, anomalies in the location of the placenta, pelvic presentation of the fetus, preeclampsia, anemia in pregnant women );

factors associated with the pathology of the reproductive system (infantilism, anomalies in the development of the genital organs, the age of a woman over 30 and under 18 years of age, menstrual irregularities, neuroendocrine disorders, history of induced abortions, miscarriage, uterine surgery, fibroids, inflammatory diseases of the female genital area );

general somatic diseases, infections, intoxications, organic diseases of the central nervous system, obesity of various genesis, diencephalic pathology;

fetal factors (FGR, intrauterine fetal infections, anencephaly and other malformations, overripe fetus, immunological conflict during pregnancy, placental insufficiency);

iatrogenic factors (unreasonable and untimely use of labor-stimulating agents, inadequate labor pain relief, untimely opening of the fetal bladder, rough examinations and manipulations).

Each of these factors can have an adverse effect on the nature of labor activity both independently and in various combinations.

PATHOGENESIS

The nature and course of childbirth are determined by a combination of many factors: the biological readiness of the body on the eve of childbirth, hormonal homeostasis, the state of the fetus, the concentration of endogenous PGs and uterotonics, and the sensitivity of the myometrium to them. The body's readiness for childbirth is formed for a long time due to the processes that occur in the mother's body from the moment of fertilization and the development of the fetal egg until the onset of childbirth. In fact, the birth act is the logical conclusion of multi-link processes in the body of the pregnant woman and the fetus. During pregnancy, with the growth and development of the fetus, complex hormonal, humoral, neurogenic relationships arise that ensure the course of the birth act. The dominant of childbirth is nothing more than a single functional system that combines the following links: cerebral structures - the pituitary zone of the hypothalamus - the anterior pituitary gland - ovaries - the uterus with the fetus - placenta system. Violations at certain levels of this system, both on the part of the mother and the fetus-placenta, lead to a deviation from the normal course of childbirth, which, first of all, is manifested by a violation of the contractile activity of the uterus. The pathogenesis of these disorders is due to a variety of factors, but the leading role in the occurrence of anomalies in labor activity is assigned to biochemical processes in the uterus itself, the necessary level of which is provided by nervous and humoral factors.

An important role, both in induction and during labor, belongs to the fetus. The weight of the fetus, the genetic completeness of development, the immune relationship between the fetus and the mother affect labor activity. The signals coming from the body of a mature fetus provide information to the maternal competent systems, lead to suppression of the synthesis of immunosuppressive factors, in particular prolactin, as well as hCG. The reaction of the mother's body to the fetus as to an allograft is changing. In the fetoplacental complex, the steroid balance changes towards the accumulation of estrogen, which increases the sensitivity of adrenoreceptors to norepinephrine and oxytocin. The paracrine mechanism of interaction of the fetal membranes, decidual tissue, myometrium provides a cascade synthesis of PG-E2 and PG-F2a. The summation of these signals provides one or another character of labor activity.

With anomalies of labor activity, processes of disorganization of the structure of myocytes occur, leading to disruption of enzyme activity and a change in the content of nucleotides, which indicates a decrease in oxidative processes, inhibition of tissue respiration, a decrease in protein biosynthesis, the development of hypoxia and metabolic acidosis.

One of the important links in the pathogenesis of weakness of labor activity is hypocalcemia. Calcium ions play a major role in signal transmission from the plasma membrane to the contractile apparatus of smooth muscle cells. Muscle contraction requires the supply of calcium ions (Ca2+) from extracellular or intracellular stores. The accumulation of calcium inside the cells occurs in the cisterns of the sarcoplasmic reticulum. Enzymatic phosphorylation (or dephosphorylation) of myosin light chains regulates the interaction between actin and myosin. An increase in intracellular Ca2+ promotes the binding of calcium to calmodulin. Calcium-calmodulin activates the light chain of myosin kinase, which independently phosphorylates myosin. The activation of contraction is carried out by the interaction of phosphorylated myosin and actin with the formation of phosphorylated actomyosin. With a decrease in the concentration of free intracellular calcium with inactivation of the "calcium calmodulin-myosin light chain" complex, dephosphorylation of the myosin light chain under the action of phosphatases, the muscle relaxes. The exchange of cAMP in muscles is closely related to the exchange of calcium ions. With the weakness of labor activity, an increase in the synthesis of cAMP was found, which is associated with the inhibition of the oxidative cycle of tricarboxylic acids and an increase in the content of lactate and pyruvate in myocytes. In the pathogenesis of the development of weakness of labor activity, the weakening of the function of the adrenergic mechanism of the myometrium, which is closely related to the estrogen balance, also plays a role. A decrease in the formation and "density" of specific a- and b-adrenergic receptors makes the myometrium insensitive to uterotonic substances.

With anomalies of labor activity, pronounced morphological and histochemical changes were found in the smooth muscle cells of the uterus. These dystrophic processes are the result of biochemical disorders, accompanied by the accumulation of end products of metabolism. It has now been established that the coordination of the contractile activity of the myometrium is carried out by a conducting system built from gap junctions with intercellular channels. "Gap junctions" are formed by the full term of pregnancy and their number increases in childbirth. The conductive system of gap junctions ensures the synchronization and coordination of myometrial contractions in the active period of labor.

PATHOLOGICAL PRELIMINARY PERIOD

CLINICAL PICTURE

One of the frequent forms of anomalies in the contractile activity of the uterus is a pathological preliminary period, characterized by the premature appearance of contractile activity of the uterus in a full-term fetus and the absence of biological readiness for childbirth. The clinical picture of the pathological preliminary period is characterized by irregular in frequency, duration and intensity pains in the lower abdomen, in the sacrum and lower back, lasting more than 6 hours. The pathological preliminary period disrupts the psycho-emotional status of the pregnant woman, upsets the daily rhythm of sleep and wakefulness, and causes fatigue.

DIAGNOSTICS

The diagnosis of the pathological preliminary period is made on the basis of the following data:
anamnesis;
external and internal examination of the woman in labor;
hardware methods of examination (external CTG, hysterography).

TREATMENT

Correction of the contractile activity of the uterus to achieve optimal biological readiness for childbirth with b-adrenergic agonists and calcium antagonists, non-steroidal anti-inflammatory drugs:
- infusions of hexoprenaline 10 mcg, terbutaline 0.5 mg or orciprenaline 0.5 mg in 0.9% sodium chloride solution;
- infusion of verapamil 5 mg in 0.9% sodium chloride solution;
ibuprofen 400 mg or naproxen 500 mg orally.
· Normalization of a woman's psycho-emotional state.
Regulation of the daily rhythm of sleep and rest (drug sleep at night or when pregnant women are tired):
- preparations of the benzadiazepine series (diazepam 10 mg 0.5% solution i / m);
- narcotic analgesics (trimeperidine 20-40 mg 2% solution i/m);
- non-narcotic analgesics (butorphanol 2 mg 0.2% or tramadol 50–100 mg IM);
- antihistamines (chloropyramine 20–40 mg or promethazine 25–50 mg IM);
- antispasmodics (drotaverine 40 mg or benciclane 50 mg IM);
Prevention of fetal intoxication (infusion of 500 ml of 5% dexrose solution + sodium dimercaptopropanesulfonate 0.25 g + ascorbic acid 5% - 2.0 ml.
Therapy aimed at "ripening" of the cervix:
- PG-E2 (dinoprostone 0.5 mg intracervically).

With a pathological preliminary period and optimal biological readiness for childbirth with a full-term pregnancy, medical stimulation of labor and amniotomy are indicated.

PRIMARY WEAKNESS OF LABOR

The primary weakness of labor activity is the most common type of anomalies of labor forces.
The basis of the primary weakness of contractions is a decrease in the basal tone and excitability of the uterus, therefore this pathology is characterized by a change in the pace and strength of contractions, but without a disorder in the coordination of uterine contractions in its individual parts.

CLINICAL PICTURE

Clinically, the primary weakness of labor activity is manifested by rare, weak, short-term contractions from the very beginning of the first stage of labor. As the birth act progresses, the strength, duration and frequency of contractions do not increase, or the increase in these parameters is expressed slightly.

For the primary weakness of labor activity, certain clinical signs are characteristic.
The excitability and tone of the uterus are reduced.
Contractions from the very beginning of the development of labor activity remain rare, short, weak (15-20 seconds):
G frequency for 10 minutes does not exceed 1-2 contractions;
The force of contraction is weak, the amplitude is below 30 mm Hg;
The contractions are regular, painless or slightly painful, since the tone of the myometrium is low.
· Lack of progressive cervical dilatation (less than 1 cm/h).
The presenting part of the fetus remains pressed against the entrance to the small pelvis for a long time.
The fetal bladder is sluggish, weakly pours into the contraction (functionally defective).
· During vaginal examination during contraction, the edges of the uterine os are not stretched by the force of the contraction.

DIAGNOSTICS

The diagnosis is based on:
assessment of the main indicators of the contractile activity of the uterus;
slowing down the rate of opening of the uterine pharynx;
Lack of translational movement of the presenting part of the fetus.

It is known that during the first stage of labor, the latent and active phases are distinguished (Fig. 52-29).

Rice. 52-29. Partogram: I - nulliparous; II - multiparous.

The latent phase is considered the period of time from the onset of regular contractions until the appearance of structural changes in the cervix (until the opening of the uterine os by 4 cm).

Normally, the opening of the uterine os in the latent phase of period I in primiparas occurs at a rate of 0.4-0.5 cm / h, in multiparous - 0.6-0.8 cm / h. The total duration of this phase is about 7 hours for primiparas, and 5 hours for multiparous ones. With the weakness of labor, the smoothing of the cervix and the opening of the uterine os slows down (less than 1–1.2 cm / h). A mandatory diagnostic measure in such a situation is an assessment of the condition of the fetus, which serves as a method for choosing an adequate management of childbirth.

TREATMENT

Therapy of primary weakness of labor should be strictly individual. The choice of treatment method depends on the condition of the woman in labor and the fetus, the presence of concomitant obstetric or extragenital pathology, the duration of the birth act.

The composition of therapeutic measures includes:
amniotomy;
Appointment of a complex of agents that enhance the action of endogenous and exogenous uterotonics;
the introduction of drugs directly increasing the intensity of contractions;
the use of antispasmodics;
prevention of fetal hypoxia.

The indication for amniotomy is the inferiority of the fetal bladder (flat bladder) or polyhydramnios. The main condition for this manipulation is the opening of the uterine os by 3–4 cm. Amniotomy can contribute to the production of endogenous PGs and intensify labor activity.

In cases where the weakness of labor activity is diagnosed when the opening of the uterine os is 4 cm or more, it is advisable to use PG-F2a (dinoprost 5 mg). The drug is administered intravenously, diluted in 400 ml of 0.9% sodium chloride solution at an initial rate of 2.5 µg/min. Mandatory monitoring of the nature of contractions and fetal heartbeat. In case of insufficient strengthening of labor activity, the rate of administration of the solution can be doubled every 30 minutes, but not more than up to 20 μg / min, since an overdose of PG-F2a can lead to excessive activity of the myometrium up to the development of uterine hypertonicity.

It should be remembered that PG-F2a is contraindicated in hypertension of any origin, including preeclampsia. In BA, it is used with caution.

SECONDARY WEAKNESS OF GENERAL ACTIVITIES

Secondary hypotonic dysfunction of the uterus (secondary weakness of labor) is much less common than primary. With this pathology in women in labor with good or satisfactory labor activity, its weakening occurs. This usually occurs at the end of the period of disclosure or during the period of exile.

Secondary weakness of labor complicates the course of childbirth in women with the following features:

burdened obstetric and gynecological history (menstrual irregularities, infertility, abortion, miscarriage, complicated childbirth in the past, diseases of the reproductive system);

complicated course of this pregnancy (preeclampsia, anemia, immunological conflict during pregnancy, placental insufficiency, overmaturity);

Somatic diseases (diseases of the cardiovascular system, endocrine pathology, obesity, infections and intoxication);

Complicated course of real childbirth (long anhydrous period, large fetus, breech presentation of the fetus, polyhydramnios, primary weakness of labor activity).

CLINICAL PICTURE

With secondary weakness of labor, contractions become rare, short, their intensity decreases during the period of disclosure and expulsion, despite the fact that the latent and, possibly, the beginning of the active phase can proceed at a normal pace. The opening of the uterine os, the translational movement of the presenting part of the fetus along the birth canal slows down sharply, and in some cases stops.

DIAGNOSTICS

Assess the contractions at the end of the I and in the II period of labor, the dynamics of the opening of the uterine os and the advancement of the presenting part.

TREATMENT

The choice of stimulants is influenced by the degree of opening of the uterine os. With an opening of 5-6 cm, at least 3-4 hours are required to complete labor. In such a situation, it is rational to use intravenous drip of PG-F2a (dinoprost 5 mg). The rate of administration of the drug is usual: initial - 2.5 mcg / min, but not more than 20 mcg / min.

If within 2 hours it is not possible to achieve the necessary stimulating effect, then the infusion of PG-F2a can be combined with oxytocin 5 units. In order to avoid adverse effects on the fetus, intravenous drip of oxytocin is possible for a short period of time, so it is prescribed when the opening of the cervix is ​​7-8 cm.

In order to timely adjust the tactics of labor management, it is necessary to conduct constant monitoring of the fetal heartbeat and the nature of the contractile activity of the uterus. Two main factors influence the change in doctor's tactics:
absence or insufficient effect of drug stimulation of childbirth;
fetal hypoxia.

Depending on the obstetric situation, one or another method of quick and gentle delivery is chosen: CS, abdominal obstetric forceps with the head located in the narrow part of the pelvic cavity, perineotomy.

Violation of the contractile activity of the myometrium can spread to the afterbirth and early postpartum period, therefore, to prevent hypotonic bleeding, intravenous administration of uterotonic agents should be continued in the III stage of labor and during the first hour of the early postpartum period.

EXCESSIVELY STRONG LABOR ACTIVITY

Excessively strong labor activity refers to hyperdynamic dysfunction of the contractile activity of the uterus. It is characterized by extremely strong and frequent contractions and / or attempts against the background of increased uterine tone.

CLINIC

For excessively strong labor activity is characterized by:
extremely strong contractions (more than 50 mm Hg);
fast alternation of contractions (more than 5 in 10 minutes);
increase in basal tone (more than 12 mm Hg);
Excited state of a woman, expressed by increased motor activity, increased respiration pulse, rise in blood pressure. Autonomic disorders are possible: nausea, vomiting, sweating, hyperthermia.

With the rapid development of labor due to a violation of the uteroplacental and fetal-placental circulation, fetal hypoxia often occurs. Due to the very rapid progress through the birth canal, the fetus may experience various injuries: cephalohematomas, hemorrhages in the brain and spinal cord, fractures of the clavicle, etc.

DIAGNOSTICS

An objective assessment of the nature of contractions, the dynamics of the opening of the uterine os and the advancement of the fetus through the birth canal is necessary.

TREATMENT

Therapeutic measures should be aimed at reducing the increased activity of the uterus. For this purpose, halothane anesthesia or intravenous drip of b-adrenomimetics (hexoprenaline 10 μg, terbutaline 0.5 mg or orciprenaline 0.5 mg in 400 ml of 0.9% sodium chloride solution) is used, which has several advantages:
fast onset of effect (after 5–10 minutes);
the possibility of regulating labor by changing the rate of infusion of the drug;
Improvement of uteroplacental blood flow.

The introduction of b-adrenergic agonists, as necessary, can be carried out before the birth of the fetus. With a good effect, the infusion of tocolytics can be stopped by switching to the introduction of antispasmodics and antispasmodic analgesics (drotaverine, ganglefen, metamizole sodium).

For women in labor suffering from cardiovascular diseases, thyrotoxicosis, diabetes, b-agonists are contraindicated. In such cases, intravenous drip of calcium antagonists (verapamil) is used.

The woman in labor should lie on her side, opposite the position of the fetus. This position somewhat reduces the contractile activity of the uterus.

An obligatory component of the management of such childbirth is the prevention of fetal hypoxia and bleeding in the subsequent and early postpartum periods.

DISCOORDINATED LABOR ACTIVITIES

The discoordination of labor activity is understood as the absence of coordinated contractions between the various sections of the uterus: the right and left half of it, the upper (bottom, body) and lower sections, all sections of the uterus.

Forms of discoordination of labor activity are diverse:
Distribution of the wave of contraction of the uterus from the lower segment upwards (dominant of the lower segment, spastic segmental dystocia of the body of the uterus);
lack of relaxation of the cervix at the time of contraction of the muscles of the body of the uterus (dystocia of the cervix);
spasm of the muscles of all parts of the uterus (tetany of the uterus).

Discoordination of the contractile activity of the uterus often develops when the woman's body is not ready for childbirth, including with an immature cervix.

CLINIC

Sharply painful frequent contractions, different in strength and duration (sharp pains more often in the sacrum, less often in the lower abdomen, appearing during a contraction, nausea, vomiting, a feeling of fear).
· There is no dynamics of cervical dilatation.
The presenting part of the fetus remains movable or pressed against the entrance to the small pelvis for a long time.
· Increased basal tone.

DIAGNOSTICS

Evaluate the nature of labor activity and its effectiveness on the basis of:
Complaints of the woman in labor;
the general condition of a woman, which largely depends on the severity of the pain syndrome, as well as otvegetative disorders;
external and internal obstetric examination;
The results of hardware examination methods.

A vaginal examination reveals signs of the absence of the dynamics of the birth act: the edges of the uterine os are thick, often edematous.

The diagnosis of discoordinated contractile activity of the uterus is confirmed using CTG, external multichannel hysterography and internal tocography. Hardware studies reveal irregular frequency, duration and strength of contraction against the background of increased basal tone of the myometrium. CTG performed before delivery in dynamics allows not only to observe labor activity, but also provides early diagnosis of fetal hypoxia.

TREATMENT

Childbirth complicated by discoordination of the contractile activity of the myometrium can be carried out through the natural birth canal or completed with a CS operation.

For the treatment of discoordinated labor activity, infusions of b-agonists, calcium antagonists, antispasmodics, and antispasmodics are used. With the disclosure of the uterine pharynx more than 4 cm, long-term epidural analgesia is indicated.

In modern obstetric practice, tocolysis of the bolus form of hexoprenaline (25 μg intravenously slowly in 20 ml of 0.9% sodium chloride solution) is more often used to quickly relieve uterine hypertonicity. The mode of administration of a tocolytic agent should be sufficient for a complete blockade of contractile activity and a decrease in uterine tone to 10–12 mm Hg. Then tocolysis (10 μg of hexoprenaline in 400 ml of 0.9% sodium chloride solution) is continued for 40-60 minutes. If within the next hour after the cessation of the administration of b-adrenergic agonists, the normal nature of labor is not restored, then the introduction of drip PG-F2a is started.

Prevention of intrauterine fetal hypoxia is mandatory.

Indications for abdominal delivery
burdened obstetric and gynecological history (prolonged infertility, miscarriage, poor outcome of previous births, etc.);
Concomitant somatic (cardiovascular, endocrine, bronchopulmonary and other diseases) and obstetric pathology (fetal hypoxia, overmaturity, breech presentation and incorrect insertion of the head, large fetus, narrowing of the pelvis, preeclampsia, uterine fibroids, etc.);
primiparous older than 30 years;
Lack of effect from conservative therapy.

PREVENTION

Prevention of anomalies of contractile activity should begin with the selection of women in a high-risk group for this pathology. These include:
primiparous older than 30 years and younger than 18 years;
Pregnant women with an "immature" cervix on the eve of childbirth;
women with a burdened obstetric and gynecological history (menstrual irregularities, infertility, miscarriage, complicated course and unfavorable outcome of previous births, abortions, uterine scar);
women with pathology of the reproductive system (chronic inflammatory diseases, fibroids, malformations);
Pregnant women with somatic diseases, endocrine pathology, obesity, neuropsychiatric diseases, neurocirculatory dystonia;
Pregnant women with a complicated course of this pregnancy (preeclampsia, anemia, chronic placental insufficiency, polyhydramnios, multiple pregnancy, large fetus, breech presentation of the fetus);
Pregnant women with reduced pelvis sizes.

Of great importance for the development of normal labor activity is the readiness of the body, especially the state of the cervix, the degree of its maturity, reflecting the synchronous readiness of the mother and fetus for childbirth. Laminaria, PG-E2 preparations (dinoprostone) are used as effective means to achieve optimal biological readiness for childbirth in a short time in clinical practice.