the complex physiological process that consummates pregnancy. Labor is the function by which the fetus, placenta, and fetal membranes are passed through the birth canal and expelled from the mother’s body.

In humans, a distinction is made between full-term labor, resulting in the birth of a mature fetus at the end of a 40-week pregnancy, and premature labor, resulting in the birth of an immature but viable fetus between the 28th and 39th week of pregnancy. Many systems of the body participate in the preparation for and realization of labor. The central and peripheral nervous systems are involved, as are the endocrine glands, the hormones and other biologically active substances formed in the fetus and placenta, and the neuromuscular apparatus of the uterus.

Labor involves the interaction of three components: the birth canal, the fetus with the placenta and membranes, and the expulsive contractions. The birth canal consists of the bony ring of the true pelvis, whose dimensions during childbirth are almost unchanged. It also includes the soft tissues of the uterine cervix—the vagina and the muscles of the pelvic floor, which upon stretching are capable of enlarging. A narrow pelvis often makes passage of the fetus through the birth canal impossible, and delivery by surgery is necessary (for example, Caesarean section).

The fetus is able to pass through the birth canal only when its long axis is parallel to that of the uterus (longitudinal presentation). The part of the fetus that passes through the birth canal with the most difficulty is the head—the largest and most solid part of the fetus. However, the sutures and fontanels between the bones of the fetal skull enable the head to change somewhat in shape to conform with the features of the birth canal. In 96 percent of all births the head of the fetus is directed downward (cephalic presentation), and in 3.5 percent the presenting part of the fetus is the buttocks or legs (breech presentation). Breech delivery presents some danger, mainly for the fetus. In one out of 200 deliveries the axis of the fetus is perpendicular to that of the uterus (transverse presentation, or transverse lie). In such a case the obstetrician corrects the position of the fetus by means of version or delivers the baby surgically.

There are expulsive contractions of the smooth musculature of the uterus (labor pains) and of the transverse striated muscles of the abdominal wall and diaphragm (bearing-down efforts). The uterine contractions play the major role. The rhythmic contractions of increasing frequency and severity are most intense at the moment of birth. The average duration of a uterine contraction is one to 1½ minutes; the pauses between contractions are ten to 15 minutes at the beginning of labor and two to three minutes toward the end. The uterine contractions are involuntary, whereas the abdominal contractions are to some degree voluntary—the woman can inhibit or intensify them.

Labor is divided into three stages: (1) dilatation of the cervix, (2) expulsion of the infant, and (3) expulsion of the placenta and membranes (the afterbirth).

During the period of dilatation, the cervix gradually becomes smooth, the birth canal enlarges, and the amnion enters the birth canal. After complete dilatation of the mouth of the cervix, the amnion ruptures. Sometimes the amnion ruptures earlier, resulting in a dry labor. With good contractile activity of the uterus such a complication need not interrupt a normal delivery. In rare cases, the amnion does not rupture, and the infant is “born in a nightshirt.” The amnion is quickly ruptured, so that with the start of respiration the infant does not choke on the amniotic fluid.

During the stage of expulsion of the fetus the uterine contractions are joined by the abdominal ones, which the woman perceives as downward thrusts. Passage of the fetus through the birth canal involves a number of movements. With each uterine contraction that is accompanied by an abdominal one, more and more of the head appears outside the vulvovaginal orifice. After the head is born, the shoulders, trunk, arms, and legs are expelled without any special difficulty. During the birth of the head, the tissues of the perineum stretch and may rupture. The physician or midwife attending the birth regulates the movement of the head and, so as not to damage the perineum, does not allow the head to be expelled too rapidly.

With the birth of the infant, the afterbirth period begins. Owing to the contraction of the uterine musculature along its entire length, including the site of placental attachment, the placenta separates from the uterine wall. The separation is accompanied by brief, insignificant bleeding (150–300 ml). Intense and prolonged hemorrhaging requires prompt intervention of the physician. With the expulsion of the afterbirth, labor is considered complete. The postnatal period begins, and the woman from that moment is called a puerpera.

The total duration of labor averages 15 to 20 hours in women giving birth for the first time (primiparas) and ten to 12 hours in women who have previously given birth (multiparas). The period of dilatation is longer: 13 to 18 hours for primíparas and six to nine hours for multiparas. The period of expulsion lasts one or two hours in primiparas and from five minutes to one hour in multiparas. The afterbirth period is 15 to 60 minutes (average 30).

In modern times, a decrease in the average duration of labor has been observed. This decrease is apparently due to improved health and physical stamina of women, better socioeconomic and hygienic conditions, and the improvement of obstetric care. Physiopsychological preparation for childbirth is also responsible for the decrease in labor duration. In addition, many medicinal agents and therapeutic methods (electroanalgesia) are used that promote painless childbirth, accelerate dilatation of the cervix, and intensify uterine contractions. The network of institutions in the health care system for mothers and children furnishes the Soviet woman qualified care in all stages of pregnancy and makes it possible for all women to have their babies in maternity hospitals or the maternity departments of hospitals.

Pathology. The normal course of labor may be disrupted if there are anomalies of the birth canal, such as the presence of a narrow pelvis and cicatricial stenoses of the soft tissues. Complications may also result from the defective development of the female reproductive organs or from the existence of neoplasms, such as a fibromyoma of the uterus or an ovarian cyst.

Other possible complications include improper presentation of the fetus, disturbance of uterine contractions, anomalies of the fetal head (hydrocephalus), tumors of the fetus, untimely rupturing of the amnion, abnormal structure or position of the umbilical cord (improper attachment, winding around the fetus), and improper attachment or early sloughing off of the placenta.

Various therapeutic measures are taken to protect the life and health of the mother and the infant.

In domestic animals, the course of labor is determined by the physiological state of the female, which in turn is determined by the animal’s feeding, maintenance, use, and species characteristics. Labor usually occurs at night or in the early morning. One to five days before an animal goes into labor, relaxation of the pelvic ligaments, edema of the external genitalia, discharge of mucus, and the appearance of colostrum are observed. Small domestic animals and wild animals prepare a birthing area.

There are three stages of labor: (1) preparation, (2) expulsion of the fetus, and (3) expulsion of the afterbirth. In the first stage, contractions of the uterine musculature result in complete dilatation of the cervical canal and a change in the position and limb arrangement of the fetus. The stage ends with the rupture of the allantois and discharge of the first waters. Expulsion of the fetus involves active uterine contractions and bearing down of the abdominal muscles. This stage lasts 15 to 30 minutes in mares, up to four hours in cows, 15 to 30 minutes in ewes and nanny goats, two to 20 hours in sows, and ten minutes to 12 hours in female dogs. In multiple births the offspring are born at intervals of 5 minutes to 15 hours. Expulsion of the afterbirth takes 30 minutes in mares, five or six hours in cows, two hours in ewes, and ten to 20 minutes in sows. In dogs and often sows the fetus and the afterbirth are expelled together.

On animal-raising farms, pregnant animals are placed in a special area (staffed by personnel trained in veterinary hygiene) several days before the expected date of labor. In a normal delivery, the fetus is expelled from the birth canal in a longitudinal position, with head and feet extended. Small animals are expelled with folded limbs. A fetus having breech presentation is delivered by carefully pulling the limbs.

The newborn animal is received on clean, dry litter, and its respiratory tract is freed from mucus and amniotic fluid. The mother should be allowed to lick the young’s body. The umbilical cord is tied and cut after pulsations cease in the vessels; the stub of the cord is treated with a disinfectant.

The normal course of labor may be disrupted if the fetus is not properly positioned in the uterus or if it is underdeveloped or deformed. Complications may also arise with the birth of twins and if the mother has a narrow pelvis. In difficult deliveries the veterinarian renders obstetric aid to the animal to conduct the fetus through the birth canal. If it is impossible to extract the fetus in this manner, a special surgical operation must be conducted.

the purposeful activity of a human being, in the process of which tools are used to act on nature and create use values in order to satisfy needs. When considered in such a general aspect, labor is, as K. Marx wrote, “the everlasting nature-imposed condition of human existence, and therefore is independent of every social phase of that existence, or rather, is common to every such phase” (K. Marx and F. Engels, Soch., 2nd ed., vol. 23, p. 195).

Labor has played a decisive role in man’s “coming-to-be.” Analyzing this role, F. Engels emphasized that man owes to labor the division of functions between arms and legs, the development of speech organs, the gradual transformation of the animal brain into a developed, human brain, and the perfection of his sense organs. Engaged in labor, man expanded his circle of perceptions and ideas; his acts of labor came to have a conscious character. The classics of Marxism point out that all history is nothing else but the formation of man through labor.

As a purposeful human activity, labor began with the fashioning of tools. Gradually, the quality of work improved, and labor became more diverse, multifaceted, and complex. In its simplest form, labor requires, aside from its purposeful activity, objects of labor and implements of labor.

Labor involves more than an interaction with nature. In order to produce material wealth, people enter into certain relationships, that is, production relations, with one another. The nature of these relations determines the social character of labor, for with a change in the forms of ownership there is a change in the way labor power is combined with the means of production.

Under the primitive communal system, communal ownership of the means of production determined the production relations. There was no exploitation of man by man. The level of development of the productive forces was so low that the labor expended in the production process was barely sufficient to ensure the reproduction of the labor power. Production relations in slavehold-ing societies were based on the slaveholder’s ownership of the means of production and of the workers themselves. Using ex-traeconomic constraints, the slaveholder was able to appropriate all of the surplus product and part of the necessary product created by the slave. Under feudalism, the basis of the production relations of the society was the feudal lord’s ownership of the land and his partial ownership of the workers (serfs). The principal form of constraint continued to be extraeconomic; the serf, because of his personal dependence on the feudal lord, was forced to labor in the lord’s behalf. Although the serf was able to benefit economically from labor on his own farm, the harshness of the system’s exploitation and the forced character of the labor retarded the development of productive forces.

Under capitalism, where the basis of production relations is formed by the capitalist’s ownership of the means of production, the workers are free citizens enjoying equality under the law. However, lacking the means of production, they are compelled, under the threat of hunger, to sell their labor power to the capitalist. This economic form of constraint guarantees the capitalist a massive and “voluntary” supply of sellers of labor power, power that in turn becomes a commodity. Labor power is sold for specified periods of time for a specified price. On the surface, it appears that the wages received by the worker constitute “payment for labor”; that is, that the worker is being compensated in full for his labor by the capitalist. The way in which wages are paid, that is, so much per hour or per unit of output, as well as the movement of wages, reinforces the mistaken notion that the full value of the functions of labor power—the worker’s labor—is being paid for. Marx showed the actual principle at work behind the outward appearance; he demonstrated that the value of labor power, like the value of any commodity, is determined by the labor that is socially necessary to reproduce the labor power, while wages, being a monetary expression of the value of the commodity known as labor power, usually lag behind the value of this commodity. Over and above the value of the labor power, the worker’s labor creates a surplus value, which is appropriated by the owner of the means of production, that is, the capitalist.

Under the conditions of commodity production, labor has a dual nature. On the one hand, it is concrete, as seen in, for example, the labor of a mechanic or tailor; concrete labor creates the use value of a commodity. At the same time, however, each commodity embodies human labor in a more general sense, labor that is independent of qualitative distinctions. Labor of this type, referred to as abstract labor, forms the value of a commodity. The dual nature of labor reflects the objective contradiction between private and social labor. Under capitalism, labor, in an immediate sense, is private; here, its social character is hidden. Private, capitalist ownership of the means of production serves to separate people from one another. The labor of each individual producer is his private affair. Hence, under capitalism, the labor of individual commodity producers cannot be coordinated on a societal scale. At the same time, the level of the social division of labor that has been reached objectively requires a comprehensive range of relations between commodity producers, and it creates interdependence among producers. Nevertheless, the social character of labor under capitalism manifests itself only in the marketplace, and herein lies one of the profound, antagonistic contradictions of capitalist society. As capitalism develops, the exploitation of hired labor increases, and the class struggle between labor and capital becomes more intense; this is the basic contradiction of capitalism.

Under socialism, the basis of production relations is the public ownership of the means of production. Socialist production relations give rise to new economic laws defining the character, nature, and organization of labor, among them the fundamental economic law of socialism, the law of planned proportionate development of the national economy, and the law of distribution according to labor. In the first phase of communism, labor ceases to be a burden that the individual is forced to bear; labor for one’s self and labor for the society are harmoniously combined; and labor becomes a creative activity performed in the context of socialist cooperation. Socialism guarantees full employment, a combination of material and moral stimulation in labor, an increase in the standard of living of workers and of the people as a whole based on a steady and rapid growth in labor productivity, and a gradual overcoming and resolution of nonantagonistic social distinctions and contradictions in social labor.

V. I. Lenin considered the absence of exploitation of man by man to be one of the most important features of labor under socialism. “For the first time after centuries of working for others, of forced labor for the exploiter, ” wrote Lenin, “it has become possible to work for oneself and moreover to employ all the achievements of modern technology and culture in one’s work” (Poln. sobr. soch., 5th ed., vol. 35, p. 196). The socialist state determines, in planned fashion, the best combination of labor for oneself and labor for the society, establishing the relative amounts of necessary and surplus labor and of consumption and accumulation. Socialist labor cooperation becomes a feature of the economy; it is based on the widespread socialization of production and the use of science and technology to increase labor productivity, improve working conditions, and make work easier. The principal characteristic of labor cooperation under socialism is the development of worker initiative, which manifests itself in various forms of socialist competition. With socialist cooperation, labor is voluntary in nature; labor discipline comes primarily from conviction, and workers are highly conscientious. Socialist labor cooperation harmoniously reconciles the interests of the individual with the interests of society; it also fosters the development of a new and conscientious attitude toward labor.

Under socialism, labor gradually becomes direct social labor. However, for two reasons, direct social labor is still in its first stage of development. In the first place, direct social labor does not include the labor of craftsmen, small tradesmen, and peasants having their own farms; nor does it include the labor of kolkhoz members and industrial and nonindustrial workers performing work on household plots, in markets outside the commercial network of the state, and at home. In the second place, social labor during the first phase of communism is characterized by social heterogeneity. Hence here, as Marx noted, “a given amount of labor in one form is exchanged for an equal amount of labor in another form” (K. Marx and F. Engels, Soch., 2nd ed., vol. 19, p. 19); that is, an exchange of the products of labor is made in accordance with the principle of equivalency.

Under socialism, all members of society who are physically able to work do so. A socialist society has no classes, strata, or social groups that would not take part in socially useful labor or that would live at someone else’s expense. The system of socialist production relations ensures to all a genuine right to labor, that is, a right enjoyed equally by all members of society to have a job and to receive payment for labor in accordance with the labor’s quantity and quality. The right to work is set forth in the constitutions of socialist countries. This right also means that there are opportunities for every worker to acquire a profession and improve his skills. These opportunities are provided by the state, which has organized a vast network of training programs at educational institutions and at the workplace. The industrialization of the country and the collectivization of agriculture have led to the elimination of unemployment.

The social organization and successful development of labor in a socialist economy are possible only when centralization is judiciously combined with the development of democracy and democratic forms and methods of managing social labor. In order to make fuller use of the capacities, talents, and initiative of those taking part in social production, the rights of collectives of enterprises and organizations are being expanded, and the personal, collective, and social interests of the workers are being harmoniously combined. An extremely important feature of the socialist organization of labor is the use of material and moral stimulation. The personal material interests of workers under socialism are conditioned by the social division of labor that has taken shape and by the retention of certain socioeconomic distinctions between various kinds of labor. Among the distinctions are those between rural and urban, mental and physical, skilled and unskilled, heavy and light, and mechanized and manual types of work, as well as between work performed under safe conditions and that performed under hazardous conditions. Society benefits from all types of labor, and it is in society’s interest to see that workers receive general and specialized training, that individual and social labor productivity are increased, and that product quality be at the highest level possible. These goals are achieved through the distribution of wealth according to the quantity and quality of labor and through the use of moral incentives.

Under socialism, labor typically experiences a rapid growth in productivity, making possible an increase in the standard of living of the workers and of the people as a whole. The growth in labor productivity in the national economy has been based on technological advances, changes in the structure of production, and improvements in the organization of both production and labor. The USSR and other socialist countries have achieved great success in increasing labor productivity and in raising the material and cultural level of workers and of the people as a whole.

Under developed socialism, the socioeconomic distinctions (nonantagonistic contradictions) inherent in social labor in the first phase of communism are gradually resolved and overcome (mental and physical, rural and urban). However, so long as the social division and social heterogeneity of labor exist, socioeconomic distinctions will be drawn not only between the labor of workers, peasants, and members of the intelligentsia but also between the different types of labor performed by members of the principal classes of society (workers and peasants) and between different types of labor performed by the intelligentsia. The different types of labor performed by workers in a socialist society are differentiated by the skills required, the physical difficulty, the working conditions, and the tediousness. Inequality in social labor underlies the contradictions associated with a distribution of wealth on the basis of the quantity and quality of labor. On this point, Lenin wrote that the “first phase of communism, therefore, cannot yet provide justice and equality: differences, and unjust differences, in wealth will still persist, but the exploitation of man by man will have become impossible ... the mere conversion of the means of production into the common property of the whole of society (commonly called ’socialism’) does not remove the defects of distribution and the inequality of ’bourgeois law, ’ which continues to prevail so long as products are divided ’according to the amount of labor performed’” (Poln. sobr. soch., 5th ed., vol. 33, pp. 93–94). The socioeconomic distinctions between various types of labor manifest themselves in various aspects of life, and the effects are felt by workers of all classes and groups of a socialist society. Only communism, wrote Marx and Engels, ensures that higher degree of equality within which “a different form of activity, of labor, does not justify inequality, confers no privileges in respect of possession or enjoyment” (K. Marx and F. Engels, Soch., 2nd ed., vol. 3, p. 542).

A socialist society must also resolve the contradictions relating to the social organization and remuneration of labor. Certain contradictions between personal and social interests are inherent in the very relations of socialist distribution: while each participant in production seeks to obtain the maximum payment for his own labor, the interests of the society as a whole demand that the principle of awarding payment on the basis of the quantity and quality of labor be strictly adhered to and that provision be made for ensuring the socialist accumulation necessary for expanded reproduction. Lenin accorded great importance to resolving this contradiction; he linked the very existence of the state under socialism with the need to ensure control over the measure of labor and the measure of consumption: “To this extent, therefore, there still remains the need for a state, which, while safeguarding the common ownership of the means of production, would safeguard equality in labor and in the distribution of products” (Poln. sobr. soch., 5th ed., vol. 33, p. 95).

Contradictions between personal and social interests are also engendered by violations of such economic laws as the law of distribution according to labor, of the replacement of labor expenditures, of the planned development of the national economy, and of value.

The social organization of labor under developed socialism reflects the contradictions arising between rapidly developing productive forces and obsolescent production relations. The scientific and technological revolution, which has been accompanied by an enormous growth in the cultural and educational level and level of skills of workers, is constantly improving society’s productive forces. Production relations do not always keep pace with changes in productive forces. As a result, certain forms and methods used in the social organization of labor and in management, which were once justifiable, occasionally become a force restraining the initiative of workers in social production. The resolution of these contradictions is one of the most important aspects of the economic policies of the CPSU and the state; it is being pursued through a judicious combination of centralized control, on the one hand, and independent action and initiative on the part of enterprises (associations), on the other, through a broadening of the rights of the enterprises, and through an increase in material incentives to workers.

In the higher phase of communism, labor will be considerably different from labor under socialism: “the distinction between the first, or lower, and the higher phase of communism will in time, probably, be tremendous” (V. I. Lenin, ibid., p. 98). The transformation of socialist labor into communist labor presupposes the creation of the material and technical basis for communism, the development of productive forces sufficient to ensure an enormous growth in the productivity of social labor, and the occurrence of profound changes in the nature of labor. These changes will include the emergence and development of a communist division of labor, the elimination of the nonantagonistic contradictions between mental and physical and between rural and urban labor, and, as a consequence, the overcoming of socioeconomic distinctions in labor and of the one-sided nature of labor. The worker will no longer be the direct agent of production; labor will undergo further socialization, and the private household plots of kolkhoz members and industrial and nonindustrial workers will thereby be phased out. Changes in the nature of labor will also affect the household, with women enjoying equality of rights in both society and the family. Labor will be transformed into the most vital human need; the principle “from each according to his ability” will be followed to the fullest possible extent; and there will be a gradual transition to the communist principle of distribution: “to each according to his needs.”