As we learned in the last chapter, some of the ova which are discharged into the peritoneal cavity enter the fimbriated end of the tube, while very many others perish. As a rule an ovum enters the tubal opening adjacent to the ovary from which it has been discharged, but it is possible for this tiny cell to travel across the body and enter the tube on the opposite side.

This migration of the ovum, as it is termed, has been demonstrated in cases in which pregnancy has followed removal of the ovary on one side and the tube on the other.

There are various theories as to how and why an occasional migrating ovum, floating around in a relatively large cavity, ever enters the tubal opening, which, after all, is not large. The most widely accepted belief is that the motion of the cilia lining the tubes creates a suction which draws the microscopical cell into the opening, the same cilia being the means by which the ovum is later propelled downward through the tube to the uterus.

This journey of the ovum through the tube is of enormous consequence. During its course occur the events which decide whether the ovum shall, like most of its fellows, be simply swept along to no end and lost, or whether by chance it is to receive the mysterious impulse which begins the development of a new human being.

The amazing power which enables this cell to reproduce itself, and to develop with unbelievable complexity, is acquired somewhere in the tube by meeting and fusing with a spermatozoon, the germinal cell of the male. (Fig. 17.)

The spermatozoa look very much like microscopic tadpoles, with their flat, oval heads, tapering bodies and long tails. As these tails serve somewhat as propellers, the male cells are capable of very rapid motion. But in spite of their strange appearance, they are cells after all, and resemble the female cells in that each one contains a nucleus, or germinal spot.

An almost inconceivably large number of spermatozoa, floating in the seminal fluid, is deposited in the vagina at the time of intercourse. Nature evidently supplies the male and female cells with equal lavishness, in order to provide for the large number of both kinds which must inevitably be lost, and still have enough survive to accomplish the high purpose of their creation. A very considerable number of spermatozoa enter the uterus, and are enabled through their powers of motility, to travel up into the tubes, in spite of the downward current created by the cilia. And in the tube, usually in the upper end, they meet a recently matured and discharged ovum which is being swept downward, and are attracted to it somewhat as bits of metal are drawn to a magnet. Although the ovum which is destined to be fertilized is surrounded by several spermatozoa, only one actually enters and fuses with it.

This fusion is termed impregnation, fertilization, or, in lay parlance, conception, and the instant at which it occurs marks the beginning of pregnancy. The establishment of this fact is of no little importance, since it does away with any possible controversy concerning the time at which a new life begins. The origin of the child is exactly coincident with the fusion of the male and female germinal cells.

And furthermore, the sex of the child and any inherited traits and characteristics are also established at this decisive instant. No amount of dieting, exercise nor mental effort on the part of the expectant mother can alter or influence them in the smallest degree, for the father has made his complete contribution toward the creation of the new being, and after this event the mother provides nourishment only.

All told, probably more than five hundred theories have been advanced to explain what it is that decides of which sex the forthcoming child will be.

In 1907 Dr. Schenck attracted world wide attention by announcing his belief that either sex could be produced in the expected child through the simple expedient of regulating the mother’s diet. Liberal feeding would result in boys, the sturdier sex, and frugality in girls, the smaller, frailer type of baby. But as the results of applying Schenck’s theory have scarcely borne out his claims, it is given but scant attention to-day.

The present belief regarding the causation of sex is that although there is but one kind of ovum, there are two kinds of spermatozoa, one capable of producing a male, and the other a female child. These two kinds are evidently deposited in the vagina in about equal numbers, and the sex-determining form that fertilizes any one ovum is a matter of the merest chance. Statistics show, however, that more male than female babies are born, the usual proportion being about 105 boys to 100 girls among those that reach full term. Among abortions and premature births there is also a larger number of boys than girls, and in elderly primiparÆ the ratio increases to about 130 boys to 100 girls. But as more boys die in infancy than girls, the two sexes about even up in the number of those living to adult age.

Apparently, then, there is some factor operating slightly in favor of the purposeful activities of the male-producing spermatozoa. But so far no accurate means has ever been found whereby it was possible to influence the development or discover the sex of a child before its birth.

There is a wide difference of opinion concerning the time of the month when fertilization is most likely to occur. Observations made upon the wives of sailors and under a variety of conditions suggest that the most favorable period is just before or just after menstruation which represents the second stage of the menstrual cycle.

Dr. Williams believes, however, that fertilization is most likely to occur about midway during the intermenstrual period. But since it is probable that spermatozoa are constantly present in the tubes of women who are exposed to the possibility of becoming pregnant, it is difficult to do more than speculate about the time of the month at which fertility is greatest.

Another moot question relates to the age of the woman at which it is most desirable that the first child shall be born. Recent observations made by Dr. John W. Harris upon a large number of pregnancies occurring in very young girls indicates that from a standpoint which considers solely the physical welfare of the mother and her infant, sixteen years is the most satisfactory age at which to bear the first child.

However, when motherhood is considered from all standpoints, social, ethical, spiritual as well as physical, the consensus of opinion seems to be that the twenty-third year is the most favorable age for motherhood to begin. Children have been born to little girls nine years old and to women of sixty-two, but the extremes of the reproductive years are not favorable periods for child-bearing.

As soon as a spermatozoon enters an ovum, it disappears and is completely absorbed, and, as the ovum in turn is instantly possessed of new powers, the result of this union is a cell which was previously non-existent.

This new cell is not only capable of reproduction by means of segmentation or cell division, but in the course of its sub-division and proliferation, it forms groups of cells which develop into tissues and structures widely different from each other. The entire complex human body, in addition to the placenta, cord, and membranes, arises from the single, extraordinary cell.

It first divides into two; these two divide into four; the four into eight and thus the process of division and sub-division continues until a solid mass is formed, shaped something like a mulberry and called the morula. (Fig. 18.)

While these developmental changes are taking place, the morula is being carried down the tube toward the uterus, by the sweeping motion of the ciliated membrane. The time consumed by this journey has not been definitely ascertained and though possibly it may be made in a few hours, it probably takes from five days to a week. Since the embryo is constantly moving during this time, it quite evidently has no attachment to the mother and cannot, therefore, derive any great amount of nourishment directly from her. The growth and development to this point, then, must be due chiefly to inherent powers within the mass of cells itself.

In all probability, the embryo is still in the morula stage and is about the size of the head of a pin when it reaches the uterus, where it finds that the endometrium has been prepared for its reception by the premenstrual swelling. The mucosa has grown thicker, more velvety and vascular, and its glands have increased in number and activity. The columnar epithelium of the endometrium is replaced by a thick layer of large, vacuolated cells, called decidual cells, and the uterine lining from now on is termed the decidua gravidatis. While the normal uterine mucosa is thin, averaging from 1 to 3 millimetres (0.039 to 0.117 inch) in thickness, it increases to a thickness of about 1 centimetre (? inch) during pregnancy.

The point at which the embryo attaches itself to this spongy membrane is entirely a matter of chance. It usually rests somewhere in the upper part of the uterine cavity, promptly destroys the minute underlying area of tissue by digestive action and burrows into the decidua. As the margins of the opening thus made meet and fuse above the ovum, it is completely incapsulated in a cavity of its own that has no connection with the uterine cavity. (Fig. 19.)

After this occurrence the decidua consists of three portions: the hypertrophied membrane which lines the uterus as a whole, called the decidua vera, which atrophies during the latter part of pregnancy and is also thrown off in part with the membranes during labor, and later in the uterine discharges; the decidua basalis, or the decidua serotina, is that portion lying directly beneath the embryo which later enters into the formation of the placenta; and the decidua reflexa, which surrounds and covers the buried embryo, consists of the developed and fused margins of the pit in the mucosa, that have grown over the embryo.

As the cellular activity continues within the morula, fluid appears in the centre with the result that the cells are rearranged and pushed toward the periphery, thus forming a sac. At this stage the embryo is called the blastodermic vesicle.

At one point on the inner surface of this vesicle the cells proliferate and form a mass which is sometimes called the internal cell mass, or embryonic area, and the single layer of cells comprising the remainder of the vesicular wall, the primitive chorion. The cells in the mass are at first disposed in layers, the outer layer being termed the ectoderm; the inner layer the entoderm, while a third layer which appears a little later is called the mesoderm.

Although these three primitive layers of cells have all arisen from the single cell formed by the fused spermatozoon and ovum, they are even now very different in character. The differences steadily increase until finally all of the complex fetal organs and tissues, the membranes, cord and placenta, result from their further specialization and development, as follows:

From the ectoderm arises the skin with its appendages, and the salivary and mammary glands; the nasal passages, upper part of the pharynx and the anus; the crystalline lens, the external ear, the entire nervous system, the sense organs and, in part, the fetal membranes.

From the mesoderm are derived the urinary and reproductive organs; the muscles, bones, and connective tissues and the circulatory systems.

From the entoderm are developed the alimentary canal, the thymus, thyroid, liver, lungs, pancreas, bladder and the various small glands and tubules.

It was formerly believed that the human being existed in miniature in the first cell and that its development during pregnancy was entirely a matter of increase in size. But the microscope has disproved this, and we now know that embryonic development comprises both growth and evolution.

Much of the information accepted to-day is, of course, speculative, having been deduced from observations made upon the reproductive processes of lower mammals, since the youngest human ovum which has been discovered and examined was probably two weeks old. But the evidence points quite convincingly to the belief that the early stages of development consist of proliferation of and alterations in the kinds of cells, their arrangement into groups, and a differentiation of the functional activity of these groups of cells before the mass assumes human form and develops organs.

As to terminology, some authorities call this mass the embryo during this stage of grouping and differentiation, which corresponds to the first six weeks of pregnancy, and the fetus from then until the time of delivery. By others it is designated the ovum during the first two weeks of pregnancy, the embryo from the third to the fifth week, after which it is known as the fetus.

From the nurse’s standpoint these distinctions are of no consequence, for the mass may safely be called a fetus from the time that the expectant mother looks to the nurse for guidance and care.

It is scarcely warrantable to take the time and space which would be necessary to trace in detail through its various stages the intricate development of the human body, with its attached membranes. But the whole question is so important and so interesting that we shall at least have a word of description as to its size and characteristics at successive periods.

Although the exact length of time required for the maturation of the fetus is not known, it is estimated that two hundred and eighty days, or ten lunar months, elapse between the beginning of the last menstrual period and the beginning of labor. And in spite of the difference in size among the mothers, it is found that the products of conception develop and grow at a fairly uniform rate of speed.

A new human being is the ultimate result of conception, but the chorion, amnion, placenta and umbilical cord must also be created to serve as aids in building and protecting the developing child during its uterine life. The part played by these accessory structures is so vital, in spite of being temporary, that it will be well for us to look into their origin and functions before considering the fetus itself which they serve.

The Chorion and Placenta. Very early in pregnancy, probably while the fertilized ovum is journeying down the tube, tiny, thread-like projections, called villi, appear over the surface of the primitive chorion, giving it the shaggy appearance of a chestnut burr. Shortly after this shaggy ovum reaches the uterus and is embedded in the lining, the chorion, or the outer fetal membrane, is formed, being partly derived from the ectodermal layer of cells growing within the blastodermal vesicle. The chorion grows rapidly in size and thickness, and the villi upon its surface increase in size, number and complexity by frequent branching. In so doing the villi push their way into the maternal tissues surrounding them, and destroy the capillary walls with which they come in contact. Maternal blood escapes through the destroyed walls, forming tiny hemorrhagic areas, or “lakes of blood.” The chorionic villi float freely in these pools of maternal blood, which is constantly being refreshed by an inflow of arterial and an outflow of venous blood through the mother’s vessels.

Blood vessels soon appear in these chorionic villi, and fetal blood then circulates through them. It becomes apparent, therefore, that the maternal and fetal blood streams are in such close relation that they are separated by only the thin membrane which forms the walls of the vessels in the villi. (Fig. 20.)

This arrangement makes it possible for the steadily proliferating villi to discharge one of their functions, which is to receive from the maternal blood nourishment for the embryo, and give up to the parent waste products from the growing body. This exchange of nourishment and waste matter takes place by means of osmosis. But freely as the exchange of materials occurs, there is never any contact, or mixing of maternal and fetal blood, nor does maternal blood at any time flow through fetal vessels. It was believed at one time that the fetus was nourished by milk which was in some way secreted by the gravid uterus, but this is disproved by present knowledge of the placental function.

The second function of the villi, particularly after they have developed to the placental stage, is to assist in securely attaching the embryo to the uterine wall.

The villi are equally distributed over the surface of the chorion at first, but as the sac increases in size and pushes out into the uterine cavity, they gradually atrophy and disappear, excepting over the small area beneath the vesicle where the chorion is in contact with the decidua basalis. At this site the villi become much more abundant, and it is here that the placenta eventually develops. This part of the chorion is termed the chorion frondosum, while the remainder, which is in contact with the decidua capsularis, is the chorion lÆve.

As pregnancy advances and the fetal sac enlarges, the chorion lÆve covered by the decidua capsularis, or reflexa, is pushed farther out into the uterine cavity, until finally it quite reaches the opposite wall, meets the decidua vera and obliterates the entire space which had existed between the two membranes. This means that instead of a uterine cavity lined with decidua, and a tiny capsule somewhere off to the side lined with chorion, the latter has distended until it completely fills and really becomes the cavity within the uterine walls, thus lining the uterus with chorion and crowding the original lining out of existence. The decidudae capsularis and vera fuse in time and finally the capsularis degenerates and disappears.

The Amnion. Returning for a moment to the blastodermal stage of the ovum, we find that the amnion, or inner membrane, first appears as a tiny vesicle over the dorsal surface of the embryo. Very soon, however, it invests the embryo completely, and the membranous sac is intact, excepting where it is pierced by the umbilical cord. The amnion, too, is derived in part from the ectoderm, but is a stronger, denser membrane than the chorion. At first there is an appreciable space, and some fluid, between the two membranes, but as the amnion increases in size with the advance of pregnancy, it comes in contact with and is loosely adherent to the chorion.

Very early in its development the amniotic sac contains a pale yellow fluid known as the amniotic fluid, or liquor amnii, in which the fetus floats. This fluid increases in amount until the end of pregnancy and though the quantity is variable, it usually amounts to about a quart.

The source of the liquor amnii is not definitely known, but it is generally believed to be of maternal origin, secreted from the amniotic membrane, though the possibility of its consisting partly of fetal urine cannot be overlooked. It is about 99% water, containing particles of dead skin and lanugo, a soft downy hair cast off from the body of the fetus, traces of albumen and both organic and inorganic salts.

The amniotic fluid serves a variety of purposes. Since the intestines of the fetus contain lanugo and particles of dead skin, it is evident that the child swallows some of this fluid during its uterine life, and possibly obtains in this way much of the fluid necessary for its development.

The increasing bulk of the fluid serves to distend the fetal sac and surrounding uterus, and thus provides the fetus with room for growth and movement. It also prevents adhesions between the child’s skin and the amnion, which are a factor, when by mischance they do occur, in causing monstrosities and intrauterine amputations. The fluid with which it is surrounded keeps the fetus at an equable temperature in spite of variations of temperature in the mother’s environment, and minimizes the danger of injury to the fragile little body, from pressure or blows on the mother’s abdomen. And by acting as a water wedge, forced down by uterine contractions at the time of labor, it dilates the cervix sufficiently to permit the expulsion of the full term child.

The placenta. The placenta, in lay parlance the after-birth, is really a thickened, amplified portion of the fetal sac, which has developed at the site of the implantation of the ovum. It is partly fetal and partly maternal in origin, being developed jointly from the chorion frondosum with its branching villi, and the underlying decidua basalis.

The chorionic villi already referred to grow and branch in a tree-like fashion (Fig. 22), and push their way farther and farther into the uterine tissues creating the intervillous spaces which fill with maternal blood. From the time that the first fetal blood vessels appear in these floating villi, until the child is born, there is a constant exchange of nutriment and waste matter between the maternal and fetal blood; the arterial maternal blood in the intervillous spaces giving to the fetal blood in the villi the oxygen and other substances necessary to nourish and build the growing young body, and receiving in return the broken-down products of fetal activity. The waste is carried by the maternal blood stream to the mother’s lungs, kidneys and skin, by which it is excreted.

This exchange of substances is accomplished by osmosis and also by selective powers of the cells in the villi. Thus the placenta virtually serves the fetus as lungs, stomach, intestines and kidneys throughout its uterine life.

In addition to the nutritive substances in the mother’s blood, such as albumen, iron and fat which are so altered by cell action as to be absorbable through the villi, certain protective substances as the anti-toxines of diphtheria, tetanus, colon and typhoid bacilli are evidently transmitted from the maternal to the fetal circulation. It is claimed by some authorities that pathogenic organisms, for example, anthrax, pneumonia and tubercle bacilli, may be transmitted from mother to fetus, but the reported cases are so rare that the accepted belief is that organisms are seldom transmitted, if the placenta is healthy and intact. But, according to Dr. Williams, the transmission of typhoid occurs frequently, though malarial parasites cannot pass through the villous membranes.

Only during comparatively recent years has accurate knowledge of the origin and function of the placenta been available. Many varied and interesting beliefs and superstitions gained currency in the past, but all of them were erroneous.

The description of the circulation of the blood by William Harvey in 1628 shed considerable light upon this puzzling question concerning the exchange of fuel and ash between the parent and fetal bodies. But a mistaken belief that the maternal blood actually entered and flowed through the fetal vessels resulted from his valuable discovery.

When we examine this interesting structure, the placenta, after it is cast off, we find it to be a flattened, fairly round, spongy mass, eight or nine inches in diameter, about an inch thick where the cord arises and thinning out toward the margin. Continued from the margin are the filmy fetal membranes, which together form a ruptured sac. The rupture in these membranes is the opening through which the amniotic fluid escapes, and the child passes during birth.

The placenta weighs about a pound and a quarter, or ? as much as the child, and accordingly varies in size and weight with the baby. The maternal surface (Fig. 23) having been detached from the uterine wall, is rough and bleeding and is irregularly divided into lobes while the inner, or fetal, surface is smooth and glistening and covered with the amnion. The fetal surface (Fig. 24) is traversed by a number of large blood-vessels which converge toward the point of insertion of the umbilical cord, from the vessels of which they really arise. These vessels branch and divide until their termination in the innumerable chorionic villi floating in the lakes of maternal blood.

The Umbilical Cord. The cord, or funis, is a bluish white cord about three-quarters of an inch in diameter, twisted and tortuous throughout its length of about twenty inches. It is the one actual link between the mother and her unborn child, one end being attached to the abdomen of the fetus, about midway between the ensiform and the pubis, and the other to the inner surface of the placenta. The cord is derived from the abdominal pedicle and is merely an extension of the caudal or tail end of the embryo. It is covered with a layer of ectoderm which is continuous with the ectodermal covering of the fetus.

The cord consists of a gelatinous mass known as Wharton’s jelly, in the centre of which are embedded three blood vessels; two arteries through which the vitiated blood flows to the placenta, where it gives up its ash; and one vein which carries oxygenated, nourishment-bearing blood back to the fetus. The life of the fetus, therefore, is absolutely contingent upon an uninterrupted, two-way flow of blood through the cord.

The Fetus. In tracing the development of the ovum after its implantation in the uterine lining, we begin, as previously stated, with a shaggy-looking vesicle, containing fluid, with a clump of cells hanging toward the centre from their point of attachment on the inner surface of the sac. This clump develops into the embryo.

During the first month the mass increases in size, becomes somewhat elongated and curved upon itself with the two extremities almost in contact. The abdominal pedicle, which later becomes the umbilical cord, appears; the alimentary canal exists as a straight tube and the thymus, thyroid, lungs and liver are recognizable. The heart, eyes, nose, ears, and brain appear in rudimentary form and the extremities begin to be evident as tiny, bud-like projections on the surface of the embryo.

By the end of the fourth week the sac is about the size of a pigeon’s egg and has two walls. The outer wall, or chorion, as we have already seen, is covered with villi, and the amnion, or inner wall, is smooth; the contained embryo is surrounded by amniotic fluid and measures about 10 millimetres or 4 inches in length.

By the end of the second month, or eighth week, the head end of the embryo has greatly increased in size and is about as large as the rest of the body. Bone centres appear in the rudimentary clavicles; the kidneys and supra-renal bodies are formed; the limbs are more developed, webbed hands and feet are formed, the external genitalia are apparent but the sex is not distinguishable. The amnion is distended with fluid, but it is not yet in contact with the chorion; the chorionic villi have become more luxuriant on that part of the chorion resting on the decidua basalis, the future site of the placenta. The approximate weight of the embryo is 4 grams and its length 25 millimetres or an inch.

By the end of the third month, or twelfth week, centres of ossification have appeared in most of the bones, the fingers and toes are separated and bear nails in the form of fine membranes; the umbilical cord has definite form, has increased in length and begun to twist. The neck is longer, teeth are forming and the eyes have lids. The amnion and chorion are now in contact, and the villi have disappeared excepting at one point where a small, but complete placenta has developed. The embryo is about 9 centimetres long and weighs about 30 grams.

By the end of the fourth month, or sixteenth week, all parts show growth and development; lanugo appears over the body; the sex organs are clearly distinguishable and there is tarry fÆcal matter, called meconium, in the intestines. The placenta is larger, the cord longer, more spiral and also thicker because of the Whartonian jelly which is beginning to form. The fetus is about 15 centimetres long and weighs about 120 grams.

By the end of the fifth month, or twentieth week, the fetus has both grown and developed markedly. It is now covered with skin on which are occasional patches of vernix caseosa, a greasy, cheesy substance consisting largely of a secretion of the sebaceous glands. There is some fat beneath the skin but the face looks old and wrinkled. Hair has appeared upon the head and the eyelids are opening. It is usually during the fifth month that the expectant mother first feels the fetal movements which are commonly referred to as “quickening.” The body is about 25 centimetres long and weighs about 280 grams.

By the end of the sixth month, or twenty-eighth week, the fetus still looks thin and scrawny, the skin is reddish and is well covered with vernix caseosa and the intestines contain an increased amount of meconium. If born at this time the child will move quite vigorously and cry feebly. Although it is not likely to live for any length of time, every effort should be made to save its life, for it may be that the high rate of mortality at this age is due to the inadequacy of the attempts which are usually made to save the child rather than to the frailty of the child itself. It is about 35 centimetres long and weighs about 1200 grams.

By the end of the eighth month, or thirty-second week, the child has grown to about 42 centimetres in length and 1900 grams in weight, but continues to look thin and old and wrinkled. The nails do not extend beyond the ends of the fingers but are firmer in texture; the lanugo begins to disappear from the face but the hair on the head is more abundant. If born at this stage, the baby will have a fair chance to live, if given painstaking care. This is true in spite of the ancient superstition, still widely current, that a seven months’ baby is more viable than one born at eight months (meaning calendar months). The fact is that after the eighth lunar month, a little more than seven calendar months, the probability of the child’s living increases rapidly with the length of its intra-uterine life.

By the end of the ninth month, or thirty-sixth week, the increased deposit of fat under the skin has given a plumper, rounder contour to the entire body; the aged look has passed and the chances for life have greatly increased. The baby now weighs about 2500 grams and is about 46 centimetres long.

The end of the tenth month, or fortieth week, usually marks the end of pregnancy. (Fig. 27.) The average, normally developed baby has attained a length of 50 centimetres (20 inches), and a weight of 3250 grams, or about 7¼ pounds, boys usually being about three ounces heavier than girls.

It must be remembered, however, that these figures merely represent the average drawn from a large number of cases, for there may be a variation in weight among entirely normal healthy babies from a minimum of 2300 grams (5 pounds) to as high as 5000 grams (11 pounds), or more. Babies actually weighing more than 12 pounds are seldom born, in spite of legends and rumors to the contrary.

The length of a normal baby is less variable than the weight. In fact, it is so nearly constant in its increase during the successive months of pregnancy, that the age of a prematurely born fetus may be fairly accurately estimated from its length. This fact is of no little practical importance, since it aids the obstetrician in making a prognosis as to the child’s prospect of living, for he can estimate its intra-uterine age from its body length.

The size of the baby is affected by race, colored babies, for example, averaging a smaller weight than white babies. And, as might be expected, the size of the parents is likely to be reflected in the size of their infants, large parents tending to have large children and vice versa.

The number of children which the mother has previously borne is also a factor, since the first child is usually the smallest, the size of those following showing an increase with the mother’s age up to her twenty-eighth or thirtieth year, provided the successive pregnancies do not occur at too frequent intervals.

The expectant mother’s general state of health, her state of nutrition, the character of her surroundings and her mode of living may be expected to influence her baby’s welfare. Hence, women who live in comfortable, or luxurious circumstances usually have more robust babies than those who are run down, poorly nourished or overworked. All of which hints at the great value of prenatal care which will be taken up in detail in a later chapter.

A multiple pregnancy is one in which the pregnant uterus contains two or more embryos, these being termed twins when there are two and triplets when there are three; quadruplets, quintuplets and sextuplets when there are four, five and six embryos, respectively, six being the largest accredited number on record.

The tendency to multiple pregnancies is apparently inherited, and it sometimes happens that several members of the same family connection have this predisposition, as evidenced by the number of twins and triplets to be found among relatives. It is estimated that twins occur once in 90 pregnancies and triplets once in about 7000 cases.

Twin pregnancies may result from the fertilization of one or of two ova, and are designated as single ovum or double ovum twins respectively. In single ovum twins the egg becomes divided early in its development and two embryos are formed. In such a case there is one placenta, one chorion and two amnions and the babies are of the same sex.

In double ovum twins two ova are fertilized; both may come from the same ovary or there may be one from each side. When double ovum twins occur, there are two placentÆ, as a rule, though they may be somewhat fused; two amnions and two chorions and the babies may be of the same sex or each of a different sex.

Twins are often prematurely born and each one is likely to be smaller than a baby resulting from a single pregnancy, but their combined weight is greater than that of one normal baby.

An extra-uterine pregnancy may be defined as a pregnancy which develops outside of the uterus, usually in a tube or ovary. Although in the normal course of events the fertilized ovum travels down the tube and becomes attached to the uterine lining, it is possible for it to stop, and more or less completely develop at any point along the way between the Graafian follicle, from which it has been projected, and the uterus toward which it is traveling. If the fetus develops in the ovary, it is termed an ovarian pregnancy, and a tubal pregnancy if it occurs in the tube, the latter being the most frequent variety of extra-uterine pregnancy.

In the opinion of Dr. Mall, only about 1 per cent of all extrauterine pregnancies are capable of going to term. There may be an abortion, when the fetus and membranes are partly or completely extruded from the fimbriated end of the tube into the peritoneal cavity; or a rupture of the tube, when the fetus, with or without the membranes, may be expelled into the peritoneal cavity, or between the folds of the broad ligament. If the greater part of the placenta remains attached to the site of its development, in the case of a ruptured tube, it is possible for the fetus to live and grow and even go to term. But if the placenta is nearly, or completely separated, the fetus perishes and may be largely absorbed by the maternal organism, or mummified, or putrefactive changes may take place. It is usually customary to terminate an extra-uterine pregnancy as soon as it is diagnosed, for only a very small number can be expected to go to term, the majority aborting, or rupturing the tube, with serious hemorrhage from the mother as a frequent result.

To sum up the normal pregnancy, we find that in the course of ten lunar months, following the fertilization of an ovum, the uterus grows from a small, flattened, pelvic organ, three inches in length, to a large, globular, muscular sac, constituting an abdominal tumor about fifteen inches long; it increases its weight thirty-two times, that is from two ounces to two pounds, while the capacity of the uterine cavity is multiplied five hundred times. Within the cavity is a child weighing about seven and a quarter pounds, surrounded by a quart or so of amniotic fluid. This fluid is contained in the sac composed of the fetal membranes, the amnion and chorion, which are excessively developed at one point into the placenta. The placenta, in turn, is attached to the child by means of the umbilical cord. The total weight of the uterus and its contents at term is usually about fifteen pounds.

Quite as mysterious and inexplicable as the development of these complex structures from one tiny cell is the fact that when the new human being is ready to begin life as a separate entity, further changes occur within the mother’s body which produce uterine contractions of such a character as to entirely empty the uterus of its contents.

Signs and Symptoms of Pregnancy. Unfortunately for all parties concerned, the exact duration of pregnancy has never been ascertained, since there is no way of knowing when the ovum is fertilized, the moment which marks the beginning of pregnancy.

It is obviously impossible, therefore, to foretell exactly the date of confinement. But labor usually begins about ten lunar months, forty weeks or from 273 to 280 days after the onset of the last menstrual period.

Thus the approximate date of confinement may be estimated by counting forward 280 days or backward 85 days from the first day of the last period. Or what is perhaps simpler, and amounts to the same thing, one may add seven days to the onset of the last period and count back three months. For example, if the last period began on June third, the addition of seven days gives June tenth, while counting back three months indicates March tenth as the approximate date upon which the confinement may be expected.

This is probably as satisfactory as any known method of computation, but at best it is only approximate, being accurate in about one case in twenty. But it comes within a week of being correct in half the cases, and within two weeks of the date in eighty per cent of all pregnancies.

Another method sometimes employed by obstetricians is to estimate the month to which pregnancy has advanced by measuring the height of the fundus, and thus forecasting the probable date of confinement. It is generally agreed that the ascent of the fundus is fairly uniform and that at the fourth month it is half way between the symphysis and umbilicus; at the sixth month, on a level with the umbilicus; at the seventh month, three fingers’ breadth above; at the eighth month, six fingers above the umbilicus and at the ninth month just below the xiphoid. At the tenth month, or term, the fundus sinks downward to about the position it occupied at the eighth month. (Figs. 31, 32 and 33.)

This method, however, is measuring by months, not days, and leaves a wide margin for conjecture as to the exact date.

Still another method is to count forward 20 or 22 weeks from the day upon which the expectant mother first feels the fetus move. As we shall see presently, this experience, termed “quickening,” usually occurs about the 18th or 20th week, but is so irregular that it is unreliable as a basis for computation.

The possibility of estimating the date of confinement is still further complicated by the fact that there is evidently considerable variation in the length of entirely normal pregnancies. Many healthy children are born before ten lunar months have elapsed, while more deliveries occur after than on the expected date. The first pregnancy is usually shorter than subsequent ones, and women who are well nourished and well cared for have longer pregnancies, as a rule, than those less favored.

Although the symptoms of pregnancy have been observed throughout the ages by women who have borne children, and accoucheurs of one sort and another who have attended them, a positive diagnosis at an early stage of this condition is sometimes still baffling to the most experienced obstetricians.

So many symptoms of pregnancy are known to women the world over, that an expectant mother frequently recognizes her pregnant state at a very early date. This is particularly true of women who have previously borne children. But as these same symptoms closely resemble those of other conditions, they are not infrequently ascribed to impaired health, with the result that the pregnancy is not discovered until it is well advanced, and then sometimes only by accident. And one even hears of an occasional case in which a woman is entirely unaware of her condition until she goes into labor.

The converse is also true, for women sometimes erroneously believe themselves pregnant because of the appearance of well recognized symptoms, which are due to other causes. This condition is known as pseudocyesis, or spurious pregnancy, and is usually found in women approaching the menopause or in young women who intensely desire offspring. It is a pathetic occurrence, and the patient is usually so tenacious of her belief in her approaching motherhood that the obstetrician dispels it only with great difficulty.

For all of these and other reasons it is customary to divide the signs and symptoms of pregnancy into three groups, under self-explanatory headings, namely: presumptive symptoms, and probable and positive signs. Although it is never within the province of a nurse to make a diagnosis, it is important that she be familiar with symptoms. In obstetrics this seems to be particularly true, and especially so if the nurse be engaged in prenatal work or in any branch of public health nursing that brings her in touch with possible or expectant motherhood. The wider her grasp of obstetrical knowledge, the more helpful and reassuring can be her relation to her patient. To this end, therefore, we will take up the most reliable symptoms and signs of pregnancy.

The presumptive signs, which consist largely of subjective symptoms observed by the patient herself, are as follows:

1. Cessation of menstruation. This is usually the first symptom noticed. A period may be omitted from any one of several causes, as has been explained in Chap. II but in a healthy woman of the childbearing age, whose menses have previously been regular, the missing of two successive periods after intercourse is a strong indication of pregnancy.

2. Changes in the breasts. These also occur early. The breasts ordinarily increase in size and firmness, and many women complain of throbbing, tingling or pricking sensations and a feeling of tension and fullness. The breasts may be so tender that even slight pressure is painful. The nipples are larger and more prominent, while both they and the surrounding areolÆ grow darker. The veins under the skin are more apparent and the glands of Montgomery larger. If in addition to these symptoms it is possible to express a pale yellowish fluid from the nipples of a woman who has not had children, pregnancy may be strongly suspected. But practically all of these symptoms may be due to causes other than pregnancy, and, in the case of a woman who has borne children, milk may be present in the breasts for months, or even years, after the birth of a child.

3. “Morning sickness,” as the name suggests, is nausea, sometimes accompanied by vomiting, from which many pregnant women suffer immediately upon arising in the morning. It varies in severity from a mild attack when the patient first lifts her head to repeated and severe recurrences during the day, and even into the night. More frequently, however, the discomfort passes off in a few hours. When the vomiting persists, it is termed “pernicious vomiting” and is usually accepted as a possible symptom of a reflex, toxic or neurotic condition, all of which will be discussed with the complications of pregnancy. Morning sickness may begin immediately after conception, but sets in as a rule about the sixth week and continues until the third or fourth month. It occurs in about half of all pregnancies and is particularly common among women pregnant for the first time. But on the other hand, it must be borne in mind that many non-pregnant women suffer from nausea in the morning; many women go throughout the entire period of gestation without any such disturbance, while others are entirely comfortable in the morning and nauseated only during the latter part of the day.

4. Frequent micturition. There is usually a desire to void urine frequently during the first three or four months of pregnancy, after which the tendency disappears, but recurs during the later months. The inclination may be due in part to nervousness, but is largely caused by pressure exerted by the enlarging uterus upon the bladder, and not to any functional disturbance of the kidneys, as is sometimes believed. Pressure on the outside of the bladder gives much the same sensation as is experienced when the bladder is distended with urine. After the uterus rises from the pelvic cavity into the abdomen, it no longer crowds the bladder, until it drops during the last month or six weeks, when it again presses upon this organ and cause a desire to void.

5. Increased discoloration of the pigmented areas of the skin, and also of the mucous membranes, is another early symptom of pregnancy. In addition to the deepened tint of the nipples and surrounding areolÆ, the so-called linea nigra appears upon the abdomen, extending from the pubis toward the umbilicus. There are also the dark bluish or purplish appearance of the vulval and vaginal linings; the yellowish, irregularly shaped blotches which sometimes appear on the face and neck, known as chloasma: dark circles under the eyes and the striÆ on the abdomen.

6. “Quickening” is the widely used term which designates the mother’s first perception of the fetal movements. It occurs about the eighteenth or twentieth week, and is regarded by some obstetricians as a positive and by others as merely a strongly presumptive sign of pregnancy. The sensation is likened to a very slight quivering or tapping, or to the fluttering of a bird’s wings imprisoned in the hand. Beginning very gently, these movements increase in severity as time goes on until they become very troublesome toward the latter part of pregnancy, amounting then to sharp kicks and blows. Women who have had children can usually be relied upon to distinguish between quickening and the somewhat similar sensation caused by the movement of gas in the intestines, but a woman pregnant for the first time may be deceived.

There are many other possible symptoms of pregnancy, but their value is very uncertain. Even the ones described above are not entirely dependable, but if two or more of them occur coincidently, they probably indicate pregnancy. Dr. Slemons sums it up by saying, “If, for example, menstruation has previously been regular and then a period is missed, the patient has good reason to suspect she is pregnant; if the next period is also missed and meanwhile the breasts have enlarged, the nipples darkened, and the secretion of colostrum has begun, it is nearly certain that she is pregnant; whether morning sickness and the desire to pass urine frequently are present is of no importance.”^[2]

The probable signs of pregnancy are chiefly discoverable by the physician after careful examination. They also are numerous and uncertain, but there are four which are considered fairly trustworthy.

1. Enlargement of the abdomen, which is first in order of importance, is apparent about the third month. At this stage the growing uterus may be felt through the abdominal wall as a tumor which steadily increases in size as pregnancy advances. Rapid enlargement of the abdomen in a woman of child-bearing age, therefore, may be taken as fair, but not positive, evidence of pregnancy. But too much reliance cannot be placed in this sign, as the abdomen may be enlarged by a tumor, fluid or a rapid increase in fat.

2. Changes in the size, shape and consistency of the uterus which take place during the first three months of pregnancy are very important indications. These are discoverable upon vaginal examination, which shows the uterus to be more ante-flexed than normal, considerably enlarged, somewhat globular in shape and of a soft, doughy consistency. About the sixth week the so-called Hegar’s sign is perceptible through bimanual examination, the fingers of one hand being pressed deeply into the abdomen, just above the symphysis and two fingers of the other hand passed through the vagina until they rest in the posterior fornix, behind the cervix. The lower segment of the uterus, which may be felt between the finger tips of the two hands, is extremely soft and compressible. This sign, named for the man who first described it, is one of the most valuable signs in early pregnancy.

3. Softening of the cervix occurs, as a rule, about the beginning of the second month. In some cases, such as certain inflammatory conditions and in carcinoma, this sign may not appear.

4. Painless uterine contractions, called Braxton Hicks from their first observer, begin during the early weeks of pregnancy and recur at intervals of five or ten minutes throughout the entire period of gestation. The patient is not conscious of these contractions, but they may be observed during the early months by bimanual examination, and subsequently by placing the hand on the abdomen. One feels the uterus growing alternately hard and soft as it contracts and relaxes.

But all of the probable signs of pregnancy, like the presumptive symptoms, may be simulated in non-pregnant conditions; hence the appearance of any one of them alone may not be deeply significant. But two or more occurring coincidently constitute strong evidence of pregnancy.

The positive signs of pregnancy, of which there are three, are not apparent until the 18th or 20th week, and all emanate from the fetus.

1. Hearing and counting the fetal heart beat is unmistakable evidence of pregnancy. The sound of the fetal heart beat is usually likened to the ticking of a watch under a pillow. The rate is from 120 to 140 per minute, being about twice as fast as the maternal pulse. So long as its rhythm is regular, however, the rate may drop to 100 or increase to 160 beats per minute without being considered abnormal, or indicative of trouble with the fetus.

2. Ability to palpate the outline of the fetus is also a positive sign of pregnancy, if the head, breech, back and extremities are unmistakably made out through the abdominal wall.

3. Perception of active and passive movements of the fetus is accepted as a third incontrovertible sign of pregnancy. There is some difference of opinion concerning the value of “quickening” alone as a positive sign of pregnancy. But if the fetal movements are also perceptible by the obstetrician through the mother’s abdominal wall or by vaginal examination, there can be no doubt about the diagnosis. The movements felt by placing the hand upon the abdomen are termed active movements, while the passive movements result from internal or external ballottement. Ballottement is accomplished by giving a sharp or sudden push to the head or an extremity, and feeling it rebound in a few seconds to its original position. Passive movements may be felt early in the fourth month, and active movements after the 18th or 20th week.

PHYSIOLOGY OF PREGNANCY

A general understanding of the physiology of pregnancy is indispensable to an appreciation of the importance of observing the present-day teachings about the hygiene of pregnancy. Upon this, in turn, must rest intelligently administered prenatal care, one of the most important branches of obstetrics.

The physiology of pregnancy really represents an adjustment of the various functions of the maternal organism, which are altered to meet the demands made upon the mother’s organs by the body which is developing, growing and functioning within hers. These adjustments are in the nature of an emergency service, since they come into existence and operate only while needed, which is during pregnancy, and promptly disappear when the need for them ceases with the birth of the child. The mother’s body then begins to return to its normal, non-pregnant state, which, with the exception of the breasts, which function for nine or ten months, is accomplished in a few weeks.

But in addition to the normal changes in physiology in the course of pregnancy, there are frequently abnormal changes, too, which may be symptoms of grave complications. The detection of these symptoms, and the employment of treatment which they indicate, constitute one of the most valuable aspects of prenatal care.

Although, as might be expected, the alterations in the structure and functions of the maternal organism are most marked in the generative organs, there are definite changes in other and remote parts of the body as well. And there are adjustments in metabolism, which, though not wholly understood, are now widely recognized as important. It is pretty generally believed that as a direct, result of pregnancy, certain substances are created, possibly by the corpus luteum, which circulate in the blood and definitely influence the maternal functions. It is possible that a development of the present imperfect knowledge of these substances will result ultimately in the discovery of a blood reaction which will serve to diagnose pregnancy in an early stage.

At present, we know that, in spite of the creation of an infant body weighing upwards of seven pounds, a placenta weighing more than a pound, together with an increase of about two pounds in the weight of the uterine muscle, all in the short span of nine months, the expectant mother has to eat very little more during this period than she ordinarily does to maintain her own bodily functions. This suggests a highly developed economy in the use of nutritive material by maternal cells.

We also know that the mother excretes waste materials for the fetus and must assume that this requires an increased, or adjusted, functional activity of her excretory organs, the skin, lungs and kidneys. Moreover, the secretory activity of the previously inactive mammary glands, in spite of their remoteness from the pelvis, suggests a nervous or chemical stimulation, or both, which occurs only during pregnancy.

The changes in the uterus itself, however, are unquestionably the most marked that take place during the period of gestation. Those that relate to the lining have been described in a previous chapter. The change and growth in the muscle wall are amazing. New muscle fibres come into existence; those already there increase greatly in size and there is a marked development of connective tissue.

The actual substance of the uterus is so increased that it is converted from an organ weighing two ounces into one weighing two pounds. From a firm, hard, thick walled, somewhat flattened body in its non-pregnant state, the gravid uterus assumes a globular outline and grows so soft that the fetus may be felt through the walls.

During the first few months the uterine walls increase in thickness, but later they grow progressively thinner, until by the end of pregnancy they are only about 5 millimetres thick.

This early growth of the uterus is doubtless brought about by general systemic changes rather than by the presence of the contained embryo. Evidence of this is found in the case of tubal pregnancies when there is a definite enlargement of the uterus during the early weeks. After the third month, however, the growth of the uterus is apparently due to pressure which the growing fetus makes on the uterine walls.

The cervix does not enlarge as a result of pregnancy, but it loses its hard cartilaginous consistency, becoming quite soft, and the secretion of the cervical glands is much more profuse.

The changes in the vagina are chiefly due to increased vascularity. The blood vessels are actually larger, the products of the glands are greatly increased and the normal pinkish tint of the mucous lining deepens to red or even purple.

The most important changes in the tubes and ovaries is in their position because of their being carried up from the pelvis by the enlarging uterus into the abdominal cavity. Although they increase in vascularity, ovulation is ordinarily suspended during pregnancy.

The abdomen as a whole changes in contour as it steadily enlarges, and the skin and underlying muscles are somewhat affected as a result. The tension upon the skin is so great that it may rupture the underlying elastic layers which later atrophy and thus produce the familiar striÆ of pregnancy, known variously as the striÆ gravidarium and the linea albicantes. Fresh striÆ are pale pink or bluish in color, but after delivery they take on the silvery, glistening appearance of scar tissue, which they really are.

In a woman who has borne children, therefore, we find both new and old striÆ; those resulting from former pregnancies being silvery and shining, while the fresh tears are pink or blue. StriÆ may be found also on the breasts, hips and upper part of the thighs, and as they are of purely mechanical origin, are not necessarily associated with pregnancy alone. They may result from a stretching of the skin by ascites, a marked increase in fat or an abdominal tumor.

The same distension that causes striÆ sometimes causes a separation of the recti muscles. This separation, known as diastasis, is sometimes slight but frequently very marked, the space between the muscles being easily felt through the thinned abdominal wall.

The umbilicus is deeply indented during about the first three months of pregnancy. But during the fourth, fifth and sixth months the pit grows steadily shallower, and by the seventh month it is level with the surface. After this it may protrude, in which state it is described as a “pouting umbilicus.”

The increased pigmentation at the umbilicus and in the median line is scarcely to be classified among the abdominal changes, as the skin elsewhere presents the same discolored appearance. The degree of pigmentation varies with the complexion of the individual, as blondes may be but slightly tinted while the discolored areas on a brunette may be dark brown, sometimes almost black.

The changes in the breasts during pregnancy were practically all included in the enumerated signs and symptoms of pregnancy. They increase in size and firmness and become nodular; the nipple is more prominent and together with the surrounding areolÆ, grows much darker; the glands of Montgomery are enlarged; the superficial veins grow more prominent, and after the third month a thin, yellowish fluid can be expressed from the nipples. This fluid, called colostrum, consists largely of fat, epithelial cells and colostrum corpuscles and differs from milk, in its yellowish color, and in the fact that it coagulates like the white of an egg when boiled. The previously quiescent mammary glands develop very early in pregnancy an ability to select from the blood stream the necessary materials to produce a secretion. Colostrum is the product of their activity until about the third day after delivery, when milk appears.

Changes in the cardio-vascular system are among those which are not altogether understood, and it is still a moot question as to whether or not there is an actual increase in the amount of maternal blood during pregnancy. But results of the most recent investigations suggest that there is a definite increase in both the cells and the plasma. This increased amount circulating through the heart subjects it to a certain amount of strain, with the result that the organ is slightly hypertrophied and the pulse pressure is higher.

The respiratory organs do not show any marked alterations. The upward pressure of the enlarging uterus gradually shortens the height of the thoracic cavity, but if it grows sufficiently wide in compensation, there is no decrease in the capacity of the lungs. If this does not occur, the patient may suffer from shortness of breath. The larynx is sometimes reddened and edematous, a fact which explains the damaging effects which child-bearing may have upon the voice of singers.

Changes in the digestive tract during pregnancy are the morning sickness already described, and constipation. The latter is suffered by at least one half of all pregnant women, and is due chiefly to pressure of the uterus on the intestines, though impaired tone of the stretched abdominal muscles may be a factor. This condition is most troublesome during the latter part of pregnancy. There also may be gastric indigestion causing acidity, flatulence and heartburn, and intestinal indigestion giving rise to diarrhea and cramp-like pains. The appetite may be very capricious during the early weeks, and become almost ravenous later on.

Changes in the urinary apparatus include frequency of micturition mentioned among the symptoms of pregnancy.

The changes in the bony structures of the pregnant woman are characterized by partial decalcification. This is accounted for by the fact that the developing fetus requires a definite amount of calcium in the formation of its osseous structures, and unless the expectant mother absorbs an adequate quantity from her food, it must be extracted from the bones and similar structures, such as the teeth. Her bones and teeth accordingly grow softer, and we have the well-known adage, “for every child a tooth,” as well as the fact that fractures during pregnancy unite very slowly. There are also the softened cartilages which were referred to in connection with the anatomy of the pelvis. A part of the softening of the pelvic cartilages, however, is due to a temporarily increased blood supply. As will be explained in the chapter on nutrition, this partial decalcification of the mother is entirely unnecessary, and the newer knowledge of nutrition points the way to its prevention.

The skin changes consist chiefly in the appearance of striÆ and the increased pigmentation to which reference has already been made. There is also an increased activity of the sebaceous and sweat glands and the hair follicles, the latter sometimes resulting in the hair becoming much more abundant during the period of gestation. Although the pigmented areas on the breasts and abdomen never quite return to their original hue, the chloasmata, sometimes called the “masque des femmes enceintes,” practically always disappear and leave no trace, a fact that is frequently a comfort to an expectant mother.

The carriage is somewhat affected during pregnancy because the increased size and weight of the abdominal tumor shifts the centre of gravity. In an effort to preserve an upright position the woman throws back her head and shoulders and finally assumes a gait that may be described as a waddle, particularly noticeable in short women.

Temperature changes are probably not caused by pregnancy per se, though some authorities believe that there is normally a slight elevation during the latter part of the day.

Mental and emotional changes are usually included among the alterations which occur during pregnancy, but the present status of psychiatry suggests that this may not be altogether true. It is a fact that many pregnant women show marked mental and emotional unbalance, but as yet there seems to be no evidence that these states are inherently due to pregnancy, though the same condition may recur in the same woman each time that she is pregnant.

We shall consider this important subject more at length in the chapter on mental hygiene, so it may be enough simply to say at this juncture that, in a sensitively strung or uncertainly poised woman, the state of being pregnant may be merely the last straw, so to speak, that upsets her equilibrium; and that some other experience, which would be an equal strain upon her slender ability to make adjustments, would result in exactly the same mental or emotional distortion, just as certain physical signs in pregnancy may be produced also in the non-pregnant state, and are not, therefore, necessarily inherent to the gravid state.

Changes in the ductless glands are in much the same category. Functional disturbances of these glands occurring at any time may give rise to great irritability, excitability or to other mental symptoms. A non-pregnant woman with even a very slight degree of hyperthyroidism, for example, may be noticeably unstable mentally or emotionally. Since there is evidently an inter-relation and inter-dependence of the functions of the ductless glands, and since ovulation, the function of one of these glands, is suspended during pregnancy, we can readily believe that other glands would undergo changes as a result. Alterations in the thyroid are particularly apparent as it becomes enlarged and more active in the majority of pregnant women, as does also the anterior lobe of the pituitary body. This increased activity may tend to compensate for the suspended function of the ovaries. But the alterations in the functions of the other glands, compensatory though they be in part, apparently produce much the same sort of nervous symptoms that they are capable of producing in a non-pregnant woman.

Taking the condition as a whole, pregnancy is usually characterized by an improved state of health. During the first few months there may be lassitude and loss of weight, but the latter part of the period is notable for an unusual degree of general well being and for an increase in flesh over the entire body, which may amount to as much as twenty-five or thirty pounds.

About fifteen pounds of the increased weight is lost at the time of labor and a still further reduction occurs during the succeeding weeks when the mother’s body returns approximately to its original condition. But it sometimes happens that the improved state of nutrition acquired during pregnancy becomes permanent.