Obstetrics for Nurses

by Charles B. Reed

THE EXTERNAL GENITALS

The external genitals form the vulva. Under this name are included the mons veneris, the labia majora, the labia minora, the clitoris, the vestibule, the hymen and the glands of Bartholin.

The entire groove from the mons veneris to a point well up on the sacrum forms a deep fold or crevice, which is known as the genital crease. That part of the genital crease lying between the anus and vulva is technically known as the perineum (q.v.)

Fig. 6.—The external genitals. (Redrawn from Gray.)

The Mons Veneris.—The mons veneris is a gently rounded pad of fat lying just above the junction of the pubic bones (the symphysis). The overlying integument is filled with sebaceous glands and covered with hair at puberty.

The Labia Majora.—The labia majora are the large lips of the vulva. They are loose, double folds of skin extending downward from the mons veneris to the anterior boundary of the perineum and covered externally with hair. Normally they lie in apposition and conceal the vaginal opening. They correspond to the male scrotum.

The Labia Minora.—The labia minora, or nymphæ, are two small folds of skin and mucous membrane, that extend from the clitoris obliquely downward and outward for an inch and a half on each side of the entrance to the vagina. On the upper side, where they meet and invest the clitoris, the fold is called the prepuce, but on the under side they constitute the frænum.

The labia minora are sometimes enormously enlarged in the black races and are then called the Hottentot apron.

The Clitoris.—The clitoris is an erectile structure analogous to the erectile tissue of the penis. The free extremity is a small, rounded, extremely sensitive tubercle, called the glans of the clitoris. About the clitoris there forms a whitish substance called smegma. This is a good culture medium for germs and must be carefully sponged away when the vulva is prepared for delivery.

The Vestibule.—The vestibule is bounded by the clitoris above, the labia minora on the sides, and the vaginal orifice below. It contains the opening of the urethra, which is called the meatus urinarius.

The Hymen.—The hymen is a thin fold of membrane which closes the vaginal opening to a greater or lesser extent in virgins. It varies much in shape and consistency. It is sometimes absent, or it may persist after copulation, hence its presence or absence can not be considered a test of virginity. When torn, the edges shrink up and form little irregularities called carunculæ myrtiformes.

Fig. 7 A.—Varieties of hymen. (American Text Book.)

Bartholin Glands.—Bartholin glands are located on each side of the commencement of the vagina. Each gland discharges by a small duct just external to the hymen. They are often the seat of a chronic gonorrhœal inflammation and must be watched carefully, lest infection extend to the mother after labor, or to the eyes of the child in passing.

Fig. 7 B.—Varieties of hymen. (American Text Book.)

The Perineum.—The perineum is a body of muscle, fascia, connective tissue, and skin, situated between the vagina and the rectum. The vagina bends forward and the rectum backward, so a triangular area is left between them which is filled by the perineal body. It is about two inches long from before backward, and becomes progressively thinner the deeper it extends.

Fig. 8 A.—The excreting ducts of the mammary gland. (Lenoir and Tarnier.)

Fig. 8 B.—Lobules and duct of the mammary gland. (Lenoir and Tarnier.)

The perineal body is flattened out and compressed by the passage of the head and in many cases torn. (Thirty per cent of primiparas and ten to fifteen per cent of multiparas.) It should be repaired immediately.

The Mammary Glands.—The mammary glands are secondary but highly important parts of the genital system. They are formed by a dipping down of skin glands and they perform the special function of secreting milk.

The breast is made up of fifteen or twenty lobes, each of which, like a bunch of grapes, clusters about and discharges into a single tube which, in turn, leads to the nipple. The area between the lobes is filled with fat and connective tissue.

Fig. 9.—Nipple, areola, and the glands of Montgomery. (Eden.)

The nipple is pink or darkly pigmented. It is composed of erectile tissue and under stimulation, it rises from the surface of the gland so that it is easily taken into the mouth.

Fig. 10.—Supernumerary milk glands in the axillæ. They may be found also below the breasts. (Witkowski.)

Fig. 11.—The three ages of the breast—virginity, maturity, and senescence. (Witkowski.)

Surrounding the nipple is a darkly pigmented area from one inch to four inches in diameter that is called the areola. It contains hard, shot-like nodules, the glands, or tubercles, of Montgomery. These often secrete milk and sometimes become infected. It occasionally happens that more than two breasts may be found on the human female, and not infrequently pieces of mammary tissue may be discovered in the axilla or on the chest or back.

The mammary gland is undeveloped at birth, but, nevertheless it may fill with milk (witches’ milk). At puberty, after marriage, and during pregnancy, the gland reaches maturity. It is only after delivery, however, that the functional climax is attained.

CHAPTER II
PHYSIOLOGY

Ovulation.—Ovulation is the process whereby the eggs are discharged from the Graafian follicle which matures and protects them in the ovary. The egg is a true cell with one, and sometimes more than one, nucleus.

The ripening of the eggs, as well as their discharge, is attended with much general disturbance and great physical changes. This phenomenon begins from the twelfth to the fifteenth year, depending on race, climate, occupation and temperament, and marks the transition of the individual from childhood into maturity.

This period is called puberty. At this time the breasts enlarge, the hips round out, the vagina, uterus and external genitals increase in size. Hair appears upon the vulva, the emotions become more evident, and modesty develops through a consciousness of sexual difference and attraction.

Simultaneously a new function appears—

Menstruation.—Menstruation may be defined as a process wherein a bloody fluid is discharged from the uterus at regularly recurring periods between puberty and the menopause, except during pregnancy and lactation. It is a hæmorrhage which in some way is closely associated with ovulation, but it is not known positively which is the precedent of the other, or whether one causes the other.

Menstruation is not essential to pregnancy, for pregnancy may occur when the flow is normally absent, as before puberty, after the menopause, or during lactation. Nevertheless, regularity of menstruation is the rule in fertile women and clinicians agree that while conception may occur at any part of the menstrual cycle, it is most likely to happen just before or just after the menstrual flow.

The best authorities at present support the theory that ovulation usually occurs soon after the close of the menstrual period. This is confirmed by the similarity of the physical changes that take place in the endometrium during menstruation and after conception.

Fig. 12.—Development of the ovary (after Wiedersheim). A, an ingrowth of the germinal epithelium, forming a cell-cord, which breaks up into primitive Graafian follicles; B, a primitive Graafian follicle, with its contained primitive ovum; C, D, E, later stages in the development of the Graafian follicle. (Crossen.)

As the period of the flow approaches, the lining membrane of the uterus becomes hyperæmic and swollen with blood, serum, and glandular secretions. The blood vessels are engorged, the glands become longer and more tortuous, little hæmorrhages appear, and the superficial epithelium is thrown off. A large amount of mucus is produced by the increased activity of the glands, and all is discharged into the vagina as a bloody, incoagulable flow with an odor of marigolds. The process continues usually from three to seven days, when the discharge ceases and the endometrium slowly resumes its uncongested state.

Fig. 13.—Graafian follicles. One contains two ovules which, if fertilized, will produce twins. If all three ovules are fertilized, triplets will result. (Bumm.)

Meanwhile, the psychic and bodily conditions have not remained unaffected. The nervous system is disturbed, the disposition is irritable and capricious and the head may ache. The woman takes cold easily. She is indisposed to exertion from a sense of languor and malaise. Pain may develop in the back, or cramps in the pelvis, so severe as to keep the woman in bed. Frequently the approach of the period is signalized by skin changes, such as a marked odor or an eruption of acne pustules.

The flow usually returns every twenty-eight days, but it may vary within normal limits from twenty-one to thirty days. The flow continues at such intervals regularly from puberty to the menopause (change of life), which occurs between the ages of forty-five and fifty.

Conception, or Fertilization.—This is the process wherein the male element (spermatozoon) meets and unites with the female egg. From what is known from investigations of lower animals, this meeting usually takes place in the Fallopian tube.

Fig. 14.—Human spermatozoa. h, head; c, intermediate portion; t, tail. (Williams.)

The egg expelled from the ovary is carried into the open end of the tube by peritoneal currents and passed on toward the uterus by the waving action of the hair-like outgrowths of the cells (ciliæ) that line the tube, aided, possibly, by the tubal muscle.

The spermatozoon makes its way upward from the vagina by means of its tail. This activity, like the tail of a fish, or snake, or as a boat is sculled, drives the cell forward through the thin layer of fluid that covers the mucous membranes.

The arrow-shaped spermatozoon travels at a rate that completes the passage to the ovary in twenty-four hours, but spermatozoa may lie in wait for the egg a considerable time, as is shown by the fact that they have been found alive in Fallopian tubes removed three and a half weeks after copulation. As soon as the male and female elements approach each other, they exercise a powerful magnetic attraction, which draws them together, and as soon as they touch, the two cells unite and the spermatozoon almost immediately disappears.

Only one spermatozoon is required for the fertilization of an egg, and hence enormous numbers must perish without achieving their destiny.

The fertilized egg has become the ovum, and originally 1/125 of an inch in diameter, it now begins to grow, and filled with a new energy, it passes down the tube and enters the uterus. Here it comes into contact with the soft mucosa and digs a hole for itself—a nest, very much as a warm bullet might sink into ice or snow—and is soon completely surrounded by a proliferating tissue called the decidua. The woman is now pregnant. The menstrual flow does not appear, and local and systematic changes are inaugurated.

The egg enlarges rapidly. Little glove-finger-like projections (the villi) appear on its surface and dip down into the maternal tissues. Through these villi the egg gets nourishment until about the twelfth week, when the placenta forms. Externally the ovum resembles a chestnut burr. As the egg grows, the villi on the surface find it more and more difficult to secure nutriment, and except at one place, all gradually shrink and disappear. At this significant point, they increase greatly in size, number, and complexity to form the thick, cake-like placenta.

The egg or ovum is simply a growing cyst, filled with a fluid, normally sterile, in which the developing embryo lives and swims. This fluid is the liquor amnii and it is retained by a cystic wall made up of two layers—the chorion, which represents the original cell membrane, and the amnion, which develops out of the fœtus. At maturity, the ovum will contain from one to two pints of liquor amnii.

Fig. 15.—The chorionic villi about the third week of pregnancy. (Edgar.)

The Liquor Amnii.—The liquor amnii is of vast importance to the child. It allows free movement for the growing limbs and body, protects the child from sudden changes of temperature, prevents injury both from without and within, saves the child from birthmarks and deformities by keeping it from contact with the surrounding walls, and in labor lubricates the passages for the advancing part. In a measure, too, it probably serves as a food. In labor it forms a pouch called the bag of waters, which aids in dilating the os.

Fig. 16.—Diagram illustrating relations of structures of the human uterus at the end of the seventh week of pregnancy. (American Text Book.)

Gradually, as nutrition becomes more abundant at the site of the growing placenta, a stalk-like structure thrusts out from the fœtal abdomen and forms an attachment with the formative placenta. This is called the ventral stalk and as soon as the communication with the placenta is established, it is combined with other parallel structures and becomes vascularized, to form the umbilical cord.

Fig. 17.—Maternal surface of the placenta and membranes. The cord protrudes from the cavity which held the fœtus. (Edgar.)

The Umbilical Cord.—The umbilical cord at maturity measures from five to fifty inches in length and from one-half to one inch in thickness. The cord is composed of a gelatinous connective tissue, called Wharton’s jelly, in the midst of which lie the twisted vessels (two arteries and a vein) that supply the embryo with air and food and carry off the waste.

The Placenta.—The placenta or “after-birth” is an oval or circular somewhat flattened disc, six to ten inches in diameter, and three-quarters to one and one-half inches thick. It weighs about a pound and a half. It is the organ of respiration and nutrition for the fœtus.

Fig. 18.—Fœtal surface of human placenta. (Eden.)

Fig. 19.—The egg at term with uterus removed and child showing through the membranes. (Edgar.)

It is formed about the third month outside the membranes covering the child and is more or less loosely attached to the uterine wall. The umbilical cord is attached to its fœtal surface, inside the ovum. Like a flat sponge it takes oxygen, blood, and the nourishing fluids from the blood vessels in the uterine wall, carries them to the child by means of the umbilical vein, and carries back the carbonized blood and waste products by the umbilical arteries to the placenta, and there returns them to the maternal blood for disposal. The blood of the veins is bright red, and of the arteries, dark and turbid.

Fig. 20.—Normal attitude of fœtus (complete flexion). (Barbour.)

There is no direct communication between the maternal tissues and the placenta, hence all the changes occur by osmosis, and by the activity of the cells which form the walls of the villi.

The liver of the child is large and active. The stomach and intestines functionate mildly. The kidneys act, and urine is discharged into the liquor amnii, which the child occasionally swallows.

During development, the movements of the child become more and more pronounced. Arms, legs, and entire body participate in turn. Periods of rest are also observed. Gradually the child assumes a definite attitude in the uterus. It becomes more and more folded and flexed to accommodate its size to the limitations of space. The head bends on the chest, the arms are folded, the thighs flex against the abdomen, the legs on the thighs, and even the back ultimately becomes convex. It attains a complete flexion, the normal attitude of the child. As maturity approaches, the head becomes more and more palpable and seeks its usual location in the lower pole of the uterus, resting on the pelvic brim.

Fig. 21.—Fœtal skulls showing sutures. Note the differences between the anterior and posterior fontanelles. (Eden.)

Fig. 22 A.—Child’s head at term (from side), showing diameter. (American Text Book.)

Fig. 22 B.—The child’s head at term (from above), showing diameters and fontanelles. (American Text Book.)

The fœtal skull at maturity (at term) is still incompletely ossified. The bones are thin and pliable and separated at their edges by intervals of unossified membrane which form the sutures and fontanelles. Thus the skull is compressible to a slight degree and capable of much change in shape. It can be measurably moulded by the uterine contractions to suit the pelvis.

In front, the two coronary sutures meet the frontal and sagittal sutures to produce a kite-shaped figure, called the large or anterior fontanelle, or the bregma. Behind, the lambdoidal suture meets the sagittal suture to form the small or posterior fontanelle.

The large fontanelle is made up of four bones and four angles; the small, of three bones and three angles, and are usually easy to differentiate. Furthermore, the difference between these fontanelles is of great importance in labor, since by it the observer is enabled to determine the position of the head. In America, the shape of the head is that of an ovoid with the long diameter anteroposterior (Dolico-cephalic). Thus it happens that when the head is completely flexed, the smallest diameters are presented for delivery.

The important diameters of the head, with their measurements and names, are as follows:

Nape of neck to center of bregma, 9.5 cm.—Suboccipito-bregmatic diameter. Occipital protuberance to root of nose, 11.25 cm.—Occipito-frontal diameter. Between the eminences of parietal bones, 9.25 cm.—Biparietal diameter. Between anterior ends of coronal sutures, 8 cm.—Bitemporal diameter.

The smallest circumference is that of the suboccipito-bregmatic plane, which comes into relation with the brim of the pelvis when the flexion of the head is complete. It measures 27.5 centimeters.

The fœtus grows at a definite rate throughout gestation and so regularly that the increase is rarely simulated by any other condition.

To find the probable length of the fœtus at any given time, square the month of the pregnancy (up to five) and the result is the fœtal length in centimeters. After the fifth month, multiply the number of the month by five. Thus:

7th month ×5=35 cm., the approximate length of the fœtus at the lunar month.—(Hasse’s rule.)

The Mature Fœtus.—Although subject to considerable variation, the fœtus at term will weigh about seven and one-fourth pounds, and measure 50 cm. in length. The weight is far more uncertain than the length, and therefore not so reliable as a sign of maturity.

To obtain an estimate of the weight of the child at any given month of the pregnancy, the number of lunar months minus 2, is squared and divided by 2, and the result is the average weight of the child at that time in hundreds of grams. Thus:

8th month −2=6. 6×6=36. 36÷2=18, or in hundreds of grams, 1800, the weight of the child.—(Tuttle’s rule.)

Differences between the mature and immature fœtus:

Mature		Immature
1.	Skin smooth, plump, pink covered with vernix caseosa.	1.	Skin lax, wrinkled, dull red in color; little vernix caseosa.
2.	Generous amount of subcutaneous fat.	2.	Subcutaneous fat scanty.
3.	Hair abundant and from 1 to 2 inches long.	3.	Hair on scalp short.
4.	Lanugo mostly absent.	4.	Lanugo present all over body.
5.	Nails project from finger tips.	5.	Short nails on fingers and toes.
6.	Skull bones in contact except at fontanelles.	6.	Skull sutures open.
7.	Length 50 cm. born.	7.	Moves and cries feebly when
8.	Weight five to eight pounds.	8.	Weight less than five pounds.
9.	Cartilage in ear well developed.
10.	Navel in middle of body.
11.	Testes have descended in the male, and the labia majora in the female usually cover the labia minora.
12.	Moves and cries vigorously when born.

The Fœtal Circulation.—The placenta is an organ of nutrition as well as respiration, and through the umbilical vessels the food materials are brought to the fœtus and the waste products removed.

Surrounded by the jelly of Wharton that fills out the cord, and running in and out between the two arteries, the umbilical vein passes into the fœtal abdomen and divides into two branches, one, the larger, short-circuits directly into the inferior vena cava. This branch is called the ductus venosus. The other joins the portal vein and passes through the liver, after which it also enters the vena cava.

Thus the heart is fed with a mixed blood, part coming fresh from the placenta and part coming up from the lower half of the fœtus. This blood is poured into the right auricle, where it becomes mixed again with the blood coming down from the upper pole of the fœtus through the superior vena cava.

Fig. 23.—The fœtal circulation. (Edgar.)

Now a small part goes down into the right ventricle and is forced into the pulmonary arteries to supply the lungs. But the lungs are not functionating, hence the greater part is again short-circuited through the ductus arteriosus into the arch of the aorta, where it meets with the great volume of blood which passed over into the left auricle through the hole in the septum between the right and left auricles, called the foramen ovale, thence down into the left ventricle and out through the aorta to supply the rest of the fœtal body.

With the exception of the ductus venosus and the ductus arteriosus and the foramen ovale, the circulation is the same as in the adult.

The blood in the descending aorta again divides and part goes on to supply the lower extremities while the greater part leaves the internal iliac arteries by means of the hypogastric vessels and returns through the umbilical arteries to the placenta for oxygenation.

As soon as the child is born, the fœtal structures are altered. The child breathes, the pulmonary circulation is established and the ductus arteriosus is closed. The placental circulation is abolished, and the ductus venosus and the hypogastric arteries are converted into solid fibrous cords. Owing to the immediate change of pressure in the auricles, the foramen ovale closes and the circulation assumes the adult type.

CHAPTER III
NORMAL PREGNANCY

The entire body participates in the changes brought about by pregnancy. The hips and breasts become fuller, the back broadens, and the woman puts on fat. She becomes mature in appearance, but, of course, the phenomena connected with alterations in the breasts and genitals are most important, and late in pregnancy, most conspicuous.

The uterus exhibits the most marked alteration. From an organ that weighs two ounces, it becomes the largest in the body, and increases in size from two and one-half or three inches to fifteen inches. The typical pear-shape becomes spheroidal near the end of the third month, becomes pyriform again at the fifth month, and continues thus until term.

Up to the fourth month the walls become thicker, heavier and more muscular, but as pregnancy advances, more and more tissue is demanded, until at the end, a muscle wall of only moderate thickness protects the ovum. Meanwhile the muscular functions of contractibility and irritability are greatly increased.

At the fourth month the womb, which has occupied a position of anteversion against the bladder, rises out of the pelvis. It is now an abdominal organ and as it gets heavier and heavier, it rests a certain amount of its bulk on the brim of the pelvis. About the sixth month, the uppermost part of the uterus (fundus) is at the level of the umbilicus. At the eighth month, the fundus is found a little more than midway between the umbilicus and the ensiform cartilage. About two weeks before term, it reaches its highest point, the ensiform cartilage, and then sometimes sinks a little lower in the abdomen.

The ovum, or egg, does not completely fill the uterine cavity at first, but grows from its side like a fungus until the third month. Then the uterine cavity is entirely occupied and thereafter the egg and the uterus develop at an equal rate. As the uterus rises in the abdomen, it rotates to one side, usually the right, forward on its vertical axis.

Fig. 24.—Gravid uterus at the end of the eighth week. (Braune.)

The blood vessels and lymphatics also increase in size, number, and tortuosity. Many of the veins become sinuses as large as the little finger. This increased amount of fluid both within and without the uterus has a marked effect upon its consistency. The walls of the uterus, vagina, and cervix become softened, infiltrated and more distensible. There is also an increase in size and in number of the muscle cells.

During pregnancy the uterine muscle exhibits a definite functional activity. Intermittent contractions occur, feeble at first, but growing markedly stronger as pregnancy advances. These are the contractions of Braxton Hicks. They are irregular and painless, but can be felt by the examining hand. At term they merge into, and are lost in, the regular, painful contractions of labor.

The breasts can not be said to be fully developed until lactation has occurred, nevertheless, the glands show pronounced changes as a result of marriage and pregnancy.

The size of the gland, as well as the size and appearance of the nipple and areola, varies greatly in different women; but under the stimulation of pregnancy the whole gland enlarges, including the connective tissue stroma.

About the fourth month a pale yellow secretion can be squeezed from the nipple. This is called colostrum. The pigmentation extends over a wider area and deepens in color, while the increased vascularity is shown by the appearance of the blue veins under the thin tender skin. Light pinkish lines sometimes radiate from the nipple. These are striæ and are more evident in blondes.

The milk comes into the breasts about the third day after labor, and normally continues to flow for six, to ten or twelve months.

Why the pregnancy and labor induce such marked mammary activity is not known, but the fact is patent.

The skin reacts both mechanically and biologically to the stimulus of pregnancy.

Fig. 25.—Striæ Gravidarum. (Edgar.)

Striæ Gravidarum.—Striæ gravidarum appear on the abdomen similar to those observed on the breasts and are due to the same cause—mechanical stretching. When fresh, they are pinkish in color and variable in length and breadth, but attain the greatest size below the umbilicus. Occasionally they extend to the thighs and buttocks.

After labor, they become pale, silvery, and scar-like and are called linea albicantes. They are sometimes found in other conditions than pregnancy, such as tumors or ascites.

Increased Pigmentation.—Pigmentation is not limited to the breasts. On the abdomen, a dark line will appear between the umbilicus and the pubes. This is the linea nigra, and it becomes most conspicuous in the latter half of pregnancy. In the groins, the axillæ, and over the genitals, the deposit is common, and sometimes patches appear on the face, either discrete or in coalescence, to form a continuous discoloration, called chloasma; or when extensive, the “mask of pregnancy.” The pigmentation is absorbed, or at least greatly diminished, after labor. The sebaceous and sweat glands are more active.

The hair may fall out and the teeth decay. “With every child a tooth,” is the cry of tradition. These changes are due to imperfect nutrition, or to the presence of toxins in the circulation.

Eruptions of an erythematous, eczematous, papular or pustular type are not uncommon; and itching, either local or general, may make life miserable.

The blood undergoes certain modifications that are fairly constant. The total amount is increased, but the quality is poorer, especially by an increase in water and white cells and a diminution of red cells. The amount of calcium is slightly increased and the fibrin is diminished up to the sixth month, when it rises to normal again at term.

The heart is slightly hypertrophied on the right side and blood pressure somewhat raised. A marked increase in blood pressure is suggestive of eclampsia.

The thyroid gland enlarges frequently, both as a consequence of menstrual irritation and of pregnancy. Goiters may show an increase of development, which remains after labor.

The urine is diminished in amount, but increased in frequency of evacuation. The bladder is more irritable during the first and last months, and micturition may be painful and unsatisfactory. The kidneys must be watched carefully during gestation.

The nervous system is disordered in most women, but especially in those of neurotic tendencies.

Irritability, insomnia, neuralgia of face or teeth, or perversion of appetite in the so-called “longings” are the more common manifestations.

Cramps occur in the muscles of the legs, owing to varicose veins or pressure upon the lumbar and sacral plexus of nerves.

The lungs are crowded by the growing uterus and the respiration interfered with.

The liver is enlarged, but functionally it is less competent, and constipation is common.

It is probable that most of the changes enumerated above are due to the circulation through the body of some definite product of fœtal activity, which is more or less toxic in character. The more pronounced effects of this toxin will be studied under the abnormal conditions of pregnancy.

Generally, if the pregnancy is normal, the whole body responds to the stimulating influence. After the nausea and vomiting of the early months subside, the woman feels energetic and ambitious. She is eager to do something at all times and feels fatigue but slightly. Music, literature or housework engages her attention and is zealously and joyfully practiced. The world seems bright and the thought of her labor does not bring solicitude, but pleasant anticipations. The body fills out in all directions and the woman takes on the appearance of maturity.