The Matron's Manual of Midwifery, and the Diseases of Women During Pregnancy and in Childbed / Being a Familiar and Practical Treatise, More Especially Intended for the Instruction of Females Themselves, but Adapted Also for Popular Use among Students and Practitioners of Medicine

by Frederick Hollick

SECTION IV.

THE MECHANISM OF DELIVERY IN ALL THE DIFFERENT PRESENTATIONS AND POSITIONS OF THE FŒTUS.

CHAPTER X.

PRESENTATIONS AND POSITIONS OF THE FŒTUS.

The child may present several different parts of its body, at the commencement of delivery, and they may be in different positions relatively to the different parts of the Pelvis. All these require to be known.

Different authors have made different classifications of the presentations and positions, and have differently named them; but this is of little consequence, since they are still the same, no matter how they are named. I shall follow the arrangement of M. Chailly, because I think it equally perfect, and much more simple and practical, than any other yet proposed.

PRESENTATIONS.

The fœtus may present at the mouth of the Womb either by the head, the most usual way—by the lower extremities, which is the most frequent way after the head—or by various parts of the trunk, which is the least frequent way of all.

In each of these three full presentations there may be certain variations, which require to be noticed. The head, for instance, may present either by the cranium or by the face; the lower part of the body may present either by the feet, the knees, or the breech, according as the legs and thighs are flexed or extended; and the trunk may present either on the right or left side, and inclined towards the back or towards the chest, though neither the back nor abdomen ever fully present.

Each of these variations may also have slight variations again. Thus the face may present full, or by one or the other cheek, and so on. These variations however, are of little practical consequence, because we only find them at the very commencement of the labor, and they always change to the full presentation.

Practically speaking therefore, there are five full presentations, viz., the Cranium, the Face, the Breech, the Feet, or knees, and the Trunk, either by the right or left side.

The varieties of these, as already remarked, not requiring any special attention from the accoucheur, providing he is not puzzled or misled by them.

POSITIONS.

The position means the particular direction in which the presenting part of the Fœtus is placed in relation to the Pelvic straits. The Pelvis itself is supposed to be divided into two similar halves, the right and the left, and each presenting part has one particular place which is referred to as the indicating point. Thus, for instance, in the Cranium the Occipit, or behind part of the head, is the indicating point; and we therefore say, in Cranium presentations, that it is a right or left Occipital position, according as the back of the head is to the right or left side of the Pelvis. In face presentations, the chin (mentor) is the indicating point, and we therefore say it is a right or left mento position, according as the chin is towards the right or left side. In breech presentations, the child's sacrum is the indicating point, and we then say it is a right or left sacral position, according as the Sacrum is towards the right or left side of the Pelvis. In trunk presentations, which are always crosswise, the head (cephalo) is the indicating point, and we therefore say it is a right or left cephalo position, according as the head lies towards the right or left side of the mother's body.

In Cranium presentations also, the back of the head is not merely on the right or left side, but may be at two different points on each side. It may be either nearest to the Sacrum (posterior), or nearest to the pubes (anterior), but still against the Ilium; it is therefore called a right or left anterior, or posterior, occipito iliac position, as the case may be. Sometimes also, the occiput lodges immediately on the pubis, instead of going to either side, and that is called an occipito pubic position; at other times, on the contrary, it is placed against the Sacrum, instead of being on either side, and that is called an occipito sacral position.

In presentations of the head therefore, we may reckon six positions—the right and left anterior and posterior occipito iliac, and the pubic and sacral.

In presentations of the face the same; they being mento iliac and so on, instead of occipito.

In presentations of the lower extremities also the same, excepting that they are sacro iliac and so on, instead of occipito.

In presentations of the trunk we have but two positions for each side, the right and left cephalo iliac; according as the head is on the right or left side of the mother's body. The child always lying, in presentations of the trunk, crosswise—the feet on one side and the head on the other.

Most authors enumerate many more presentations and positions, but they are of little practical utility. When the head presents, for instance, the delivery takes place in nearly the same manner, let it be in what position it may. And in presentations of the face, or of the lower extremities, the particular position is of little consequence, the delivery being usually effected much the same in them all. Some of the positions are, it is true, much more favorable than others, but a spontaneous delivery, generally speaking, occurs in all of them, when the head, face, or lower extremities presents. Very frequently indeed, the less favorable positions are changed to the more favorable ones, and the worst seldom do more than impede delivery for a time, unless there be some malformation, or loss of power. I therefore refer to them more for convenience in future explanations, and to enable my readers to know what is meant by them, when they read other books; not because they are really necessary to be understood, or of any great practical use.

The celebrated Baudelocque admitted seventy-four positions, and twenty-two presentations; and the number might be made still greater, if all the variations were to be enumerated. Such classifications however, are more ingenious than useful, and they are but little noticed even by medical men.

I shall merely describe the mechanism of labor in the most frequent positions, in each presentation, because the others usually change into these; and even when they do not, the process of delivery is essentially the same, and also the mode of assisting it.

MODE OF ASCERTAINING THE PRESENTATION AND POSITION.

The Presentation.—Although in general it is not possible to ascertain with certainty, what part of the fœtus presents to the mouth of the Womb, until labor commences, yet a tolerable judgment can frequently be formed before. In head presentations, on performing ballotment, the head is felt, like a firm round tumor, occupying all the space which the finger can reach, very differently from any other part. The peculiar cramps in the female's lower limbs, and frequent inclination to urinate, mentioned in the signs of labor, are also strong indications of this presentation, being seldom experienced in any other. When the labor has actually commenced there can be but little uncertainty in these cases, for, immediately the mouth of the Womb is sufficiently open, the finger can be introduced, and the head felt like a smooth, round, and elastic bony tumor, not likely to be mistaken for anything else, if ordinary care be taken. After the waters have escaped, it can of course be felt still more distinctly. If even an inexperienced person bears in mind the shape of the head, and reflects how it must fill up the passage, and how it must feel, from being composed of separated thin bony plates, lying on a soft yielding substance like the brain, he can scarcely fail to recognize it. The sensation is very much like that of pressing a piece of firm card board on an inflated bladder, which forms a tolerable representative of the fœtal head. Sometimes there is a difficulty from a great quantity of water being intruded between the membranes and the head, which somewhat obscures the touch, but this only necessitates greater care. The water however, may be in such quantity as to entirely prevent the touch, in which case nothing can be done till the membranes break; the presentation can then be ascertained with certainty, and it will be quite early enough to render assistance, if it should be an unfavorable one. I have known some inexperienced persons mistake the bag of water itself for the head, and commit great errors in consequence.

The Face can seldom be mistaken, because the nose, or mouth, may be felt; and, by passing the finger up the side of the head, the ears also.

The trunk is in general easy of recognition. Nearly always the right or left shoulder occupies the passage, or is near to it, so that the finger may be readily passed under the arm pit. The shoulder joints, the ribs, or the shoulder blade bone, all feel very different to the head, and are not likely to be taken for it.

In presentations of the lower extremities there is still less danger of error. If the feet, or knees, occupy the passage, they can scarcely be mistaken. The breech is certainly something like the head in its form, but feels different, and is divided down the middle by the indentation between the two cheeks, along which the finger can be passed till it enters between the limbs.

In irregular presentations, as of the arms for instance, or of one leg, or an arm and leg, it is only necessary to carefully feel them, so as to ascertain their form, and the relation of their parts. Thus the fingers can be distinguished from the toes, and the feet from the hands, particularly if the ankle can be felt.

The accoucheur should ascertain the particular presentation as early as possible, because he may sometimes be of service in correcting an unfavorable one, if he is certain of it in time, and knows what he is about. He should not however, use any degree of force to ascertain it, in case he cannot do so without, but wait till the conditions are more favorable. Neither should he, with the same object, rupture the membranes too soon, for he may thereby cause considerable delay and difficulty, without any good to counterbalance it.

All the above-named presentations may, and usually do, terminate spontaneously, except those of the trunk, and even they do occasionally, though more frequently they require assistance.

Relative frequency of the different presentations.—The most favorable presentations, and positions also, are always the most frequent, while the unfavorable ones are but seldom met with. According to Madame Lachapelle, in fifteen thousand six hundred and fifty-two labors there are about fourteen thousand seven hundred and forty-nine presentations of the head and face; about five hundred and eighty-six of the breech, knees, and feet; and only about sixty-eight of the trunk, or shoulders.

Positions.—The position is generally of but little consequence, because in all the favorable presentations spontaneous delivery occurs in every position alike, and in the unfavorable presentations the same assistance is required in one position as in another. In some cases an unfavorable position of the head may be changed however, to a better one; and therefore, so far as the head is concerned, the positions are worth ascertaining.

The mode of determining the position is by feeling for the sutures and fontanelles, described in Chapter VIII; and this cannot be usually done till after the membranes are broken, when the head can be distinctly touched. By referring to Plate XXIV, the shape and position of the Fontanelles will be seen, and if the head be supposed placed with the top downwards, and the back of it to the mother's left side, they may be readily found with the finger.

In the left anterior occipito iliac position, or that when the back of the child's head is against the left side of the mother's pelvis, and nearest the pubes, while its forehead is against the right side, and nearest the sacrum,—the sagittal suture, or opening along the top, will of course run across from right to left. This opening may be distinctly felt with the finger, which should be passed along it towards the right side, and it will then reach the anterior fontanelle; afterwards it should also be passed to the left side, and then it will reach the posterior fontanelle. The difference between these two openings, in shape and size, is shown in Plate XXIV, and even if a person has never seen, or felt, the head of a newborn child, they can scarcely be taken for each other, after noticing that Plate.

If the anterior fontanelle should be felt on the left side instead of the right, and near the pubes, while the posterior fontanelles is to the right, and near the sacrum, the position must be the right posterior occipito iliac, or just the reverse of the former.

If the sagittal suture should be found to run across from the pubes to the sacrum, instead of from one side to the other, it will then indicate either an occipito pubic, or occipito sacral position, according as the back of the head is behind or before; and this can be readily ascertained by finding either of the fontanelles.

In short, if the relative position, forms, and directions of these openings in the child's head be clearly understood, the position of the head can nearly always be determined by feeling them, as will be evident by referring to our former explanation of them.

Sometimes however, the bones overlap a good deal, from the head being pressed, and then instead of an opening along the top, a seam will be felt. And sometimes, from long continued pressure, a quantity of blood, and watery fluid, will be effused under the scalp, so as to prevent the bone being distinctly touched. But these accidents seldom happen, and with ordinary care and perseverance, need not prevent the position being determined, after a little delay.

The position of other presenting parts is easily ascertained, by feeling for some known point—as the nose, or the face, the depression between the cheeks, or the breech, and so on.

Relative frequency of the different positions.—The most favorable positions, like the most favorable presentations, are also the most frequent. According to Baudelocque, in ten thousand three hundred and twenty-two cases, of head presentation, there were eight thousand five hundred and twenty-two cases when the back of the child's head was on the mother's left side, and towards the front, (or in the left anterior occipito iliac position); one thousand seven hundred and fifty-four when it was on the right side towards the front, (right anterior occipito iliac); twenty-five times to the right side, but towards the Sacrum, (right posterior occipito iliac); and nineteen times on the left, but towards the Sacrum, (left posterior occipito iliac.) Being most frequently with the back of the head towards the front on the left side, as shown in Plate XXVII; next towards the front on the right side; and but seldom towards the Sacrum, or back, on either side. In all these ten thousand cases we do not find a single instance of the head lying from back to front, in the occipito pubic, or occipito sacral positions, commonly called transverse; neither do we find a single instance in fifteen thousand six hundred and fifty-two cases recorded by Madame Lachapelle; which will show how rare such unfortunate positions must be. What this great frequency of one particular position depends upon we do not know—possibly on that cause, previously alluded to, which determines the most frequent presentation.

In the next Chapter, the mechanism of delivery, or the manner in which the child escapes out of the body, as it most frequently occurs, will be fully explained.

CHAPTER XI.

THE MECHANISM OF DELIVERY, IN A PRESENTATION OF THE HEAD.

THE LEFT ANTERIOR OCCIPITO ILIAC POSITION.

This is the presentation and position most frequently observed, perhaps fifteen out of sixteen times. In most Obstetrical works it is called the first position.

By observing the following Plates, and referring to the previous explanations of the diameters of the Pelvis, and fœtal head, in Plates IX and XXV, it will be seen that through all its changes of position, while making its exit, the head always presents by one of its shortest diameters to one of the largest diameters of the Pelvis, so that the relation between them is invariably the best that could be established; and many peculiar turnings and revolutions occur, apparently for the express purpose of bringing this about.

Before the rupture of the membranes the head presents its occipito frontal diameter, which measures four inches, to the right oblique diameter of the Pelvis, which measures four inches and a half; while its bi-parietal diameter, which measures only about three inches and a half, is presented to the other oblique diameter, also measuring four and a half—(See Plate [XIX].) Even here it will be seen that the passage is larger than the head which has to pass through it, but a more favorable position still can be obtained, by a slight movement of the Fœtus, which nature accordingly accomplishes, and also follows by others, to preserve the advantage, which will next be described.

Movements of the Fœtal Head.—There are three of these peculiar movements, each of which takes place at a particular period of the labor, and must be described separately.

First movement, flexion, and descent.—Immediately after the Membranes are broken, the contractions of the Uterus force the head into the upper strait, by the occipito frontal diameter of four inches, as already shown; but then commences the first movement, which consists in a bending of the child's chin down upon its breast, so that the forehead is carried up into the Womb; and the most prominent point of the back of the head presents to the middle of the passage, by the occipito bregmatic diameter, which is only about three inches instead of four. This of course makes the passage so much easier, and generally, immediately after this change, the head descends into the basin of the Pelvis.

It is not absolutely necessary however, for this movement to occur, for in a well formed Pelvis the head can descend without it, though not so easily; and sometimes, in fact, it does not take place, but this is unusual.

It must be recollected that this shifting of the head alters the position of the fontanelles—the posterior one being brought more to the centre of the strait, and the anterior one carried up out of reach, while previous to the movement they were both on a level. If an examination is not made therefore, till after this change, it may be difficult to determine the position, unless this is borne in mind. The following Plates show this very well.

PLATE XXVII.

It will be seen here that the neck is straightened out, and that the two fontanelles are on a line with each other.

Note.—The front of the bones are represented in this and the two following Plates, as if transparent, so that the head may be seen through them.

Plate XXVII.

This Plate represents the head just entering the upper Strait.

PLATE XXVIII.

At this time the anterior fontanelle can scarcely be reached, but the posterior one is easily to be reached, being in the open passage, on the left side. The head is now fairly within the Pelvic cavity, but still lies across from right to left.

Second Movement, Rotation of the Head.—When the Fœtus is thus brought to the bottom of the Pelvis, its head turns completely round, the back of it being brought to the front, or under the pubes of the mother, and its forehead turned against her Sacrum, as represented in Plate XXIX.

Plate XXVIII.

This Plate represents the head descended still lower in the Pelvis.

PLATE XXIX.

Here the head is seen just beginning to turn—the right side, and part of the back of it, just passing under the pubes. As the rotation becomes complete the neck straightens, so that the two fontanelles are again found on the same level. Finally the back of the head fully emerges from under the pubic arch, and the chin slides gradually out after it beneath, so that the neck of the child is encircled by the ring of the Vulva.

Plate XXIX.

This Plate represents the head still further down, and beginning to Rotate.

PLATE XXX.

Fig. 1.

Fig. 2.

In Fig. 1, the back of the head is nearly under the pubic bone, while the forehead is just passing the external opening below.

In Fig. 2, the back of the head is completely extruded, and also the chin, so that the whole head is now born.—(p. is the pubic bone, in front.)

In Fig. 1 it will be seen how the Os Coccygis, or lowest part of the back bone, (c,) is straitened out, backward, while the head is passing, as I explained before; and in Fig. 2 it has returned again to its natural position.

The reason for this rotation of the head will be obvious on calling to mind the form of the Pelvis and the external opening. On examining Plates IX and X, it will be seen that the longest diameter of the Vulva, or external opening, the antero posterior, is nearly at right angles to the longest diameters of the upper strait, the oblique. Now the longest diameter of the head is adapted to this oblique diameter, on entering the upper strait, as already explained, and it is necessary for it also to be adapted to the longest diameter of the external opening, the anterior posterior when making its exit; but as the two are not parallel the head is compelled to turn, or rotate, in order to pass from one to the other. To accomplish this however, the neck has to be twisted considerably. But when the head is fully delivered, it is immediately straitened again, by the back of the head turning towards the mother's left side, so that its proper relations with the trunk is re-established.

Third Movement, Rotation of the Shoulders.—When the head is delivered the shoulders come next, which also require to turn round a little, to adjust themselves to the long diameter of the lower strait; and as they turn within the Pelvis the head also turns, to correspond, and thus the back of it is brought opposite the middle of the mother's left thigh. Immediately this movement is effected, the shoulders rapidly escape through the external opening, the right one being in front, a little to the left of the symphysis pubes, and the left one behind, a little to the right of the os coccygis. The body then curves upwards, to accommodate itself to the curved axis of the Pelvis, and speedily follows the shoulders.

These curious movements cause the child to pass in a spiral direction, so that each part may pass through the Pelvis in the most favorable position. Sometimes all these movements are not effected, and yet the delivery may occur, though not so speedily, or safely, as when they are. The shoulders do not always fully rotate, but may nevertheless pass the opening, if the parts be large, and well relaxed. It is questionable however, if the head can ever pass the lower strait without rotating, when it enters the Pelvis diagonally, the occipit on one side and the forehead on the other; as it is necessary for either one or the other of these parts to pass under the pubes.

MECHANISM OF DELIVERY IN ALL OTHER POSITIONS OF THE HEAD.

The right posterior occipital position.—This position, called the second by some authors, and the fourth by others, is exactly the reverse of the one just described, the head lying in the same direction, but the back of it being behind, to the right of the Sacrum, and the forehead to the left of the pubes.

Precisely the same movements are gone through in this position as in the other, excepting that the head has to rotate considerably further. In the former position the back of the head is only a little to the left of the pubis, and therefore has not far to turn to pass under it; but in this position the back of the head is behind, and therefore has to turn very far round to reach the same position. The rotation is therefore more difficult, not so soon effected, and sometimes likely to be dangerous to the child.

In the other movements there are no difference worthy of notice, but it must be borne in mind that they all occur the reverse way, to what they do in the first position, because the occiput is on the right side instead of the left.

The right anterior occipital position.—This position is precisely the same as the first, but on the other side. The back of the head is in front, but to the right of the pubis instead of the left, while the forehead is behind, to the left of the Sacrum. This will be apparent enough by observing Plate XXXI.

PLATE XXXI.

This is the second most frequent position; the left anterior occipito iliac being the most frequent.

a. The Acetabulum, or socket of the hip joint.
c. The cut edge of the Womb.
c. The Foramen Ovale.
d. The top of the ilium bone, called the crest.
h. The Symphysis Pubes.
i. The ischium.
k. k. The pubic bones.

Plate XXXI.

Head in the right anterior occiput iliac position.

The mechanism of delivery is precisely the same, and all the movements occur in the same order and manner, as in the first position, but the reverse way. The rotation, for instance, being from right to left, instead of from left to right, and so of all the others.

The left posterior occipital position.—Delivery is effected the same in this as in the left anterior, or first position, excepting that the rotation is more extended, owing to the occiput being behind, as explained in the right posterior occipital position.

GENERAL REMARKS ON THE DIFFERENT POSITIONS OF THE HEAD.

In all the other positions, and their varieties, there is nothing that calls for special notice, or that is material in practice, the delivery being nearly the same in them all. No matter what position the head is placed in, the back of it nearly always comes to the front, under the pubes, even though it have to turn half round to do so. The cause of this is supposed to be the peculiar form of the parts, which give it a screw like motion, in its descent, and the shape of the external opening, which, being longest from before to behind, can only allow the long diameter of the head to pass through in the same direction.

Sometimes, it is true, the occiput passes behind, instead of coming to the front, and then the chin comes under the pubes, while the occiput presses on the coccygis. This is very seldom observed, and when it occurs the labor is more difficult and tedious, though it may still terminate spontaneously.

The resistance of the soft parts, externally, appears to be the chief cause of the head turning; for when they are much relaxed, and the child's head small, it will sometimes pass without, or in the anterior posterior position. And sometimes, when the head is large, so that it distends the parts very much, the shoulders will pass cross wise, there being room enough for them without turning. In some females, formed large, whose organs are excessively relaxed, and whose children are small, the delivery takes place without any of the movements being effected, the child passing straight through in whatever position it may happen to be: this is rarely seen however.

When there are twins they do not usually both present by the head, but one by the feet; and frequently the parts are so relaxed by the passage of the first, that the second is delivered without rotating at all, though in general it follows precisely the same movements. It sometimes happens however, that the second birth does not take place till some hours, or even days, after the first.

It may be said, in general, that all positions of the head are favorable to both mother and child, and may terminate spontaneously. It is seldom that anything more than ordinary assistance is required in any of them, and they could in general terminate without any at all, though sometimes with difficulty. The worst cases are those in which the head does not turn round, but remains across, or where the back of it turns behind, instead of coming to the front. In these cases there is great danger of the perineum, or external lips, being much lacerated, or even of an artificial passage being torn through the perineum, leading to the most serious after results. About one child also, out of every fifty, is lost in these unfavorable positions.

CHAPTER XII.

MECHANISM OF DELIVERY IN PRESENTATIONS OF THE LOWER EXTREMITIES.

This presentation includes the feet, the knees, the breech, and also the hips, there being no difference in the delivery for all these parts. It is the same also whether there be one foot, or knee, or both feet and knees.

There are but two positions worthy of notice in this presentation, and they are determined by the child's sacrum. If the sacrum, or posteriors, are to the right of the mother's Pelvis, it is called the right sacro iliac position; but if they are on the left side it is called the left sacro iliac position. The direction in which the child's pelvis is placed, is analagous to that of the head, the sacrum answering to the occiput. Thus most frequently the sacrum is on the left side, a little to the left of the pubes, (left anterior) while the abdomen faces the right side near the sacrum. When on the right side however, it is most usually nearest the sacrum, with the abdomen facing the left side near the pubes.

The lower extremities present most frequently next after the head, but still they are but seldom met with. M. P. Dubois tells us that out of twenty thousand labors he only met with eighty-five such cases. In these eighty-five cases the breech presented fifty-four times, and the feet twenty-six, the knees being found but once.

A presentation of the lower extremities may generally be recognized at an early stage, by the head being felt at the fundus of the Uterus, and by the pulsations of the fœtal heart being heard above the umbilicus, as explained in the section on Auscultation. After labor has commenced the part felt at the mouth of the Womb is irregular, and so different from the head, that it is not likely to be mistaken for it. If the knees or feet present, they can always be distinguished; and if the breech presents it can easily be recognized by its form, and particularly by the os coccygis, which can be distinctly felt at the bottom of the depression between the two cheeks. The side on which it is felt of course determines the position, and the same with the front of the knees, or the heels. The Rectum can also be reached with the finger, when the breech is touched; but great care must be taken not to intrude it too far, because with a female child the Vulva might be mistaken for it, and thus the hymen be broken, and other injury committed. The genitals of a male child are more obvious, so that the sex of the child may be usually ascertained, along with the position.

For want of proper care the breech has been mistaken for the head, and face, but this can scarcely happen if the accoucheur is attentive. It is simply necessary to call to mind what must be felt in each presentation, as the nose and mouth with the face; the two cheeks of the posteriors, with the opening between them; and also the genitals, with the breech; and it can be certainly ascertained which of these parts are really at the opening. With the knees or feet there can scarcely be a doubt.

DELIVERY IN A BREECH PRESENTATION IN THE LEFT ANTERIOR SACRO-ILIAC POSITION.

In this position the legs and thighs are turned up against the abdomen, the breech in full occupying the passage, with the sacrum to the left and in front of the mother's pelvis.

The descent of the breech usually takes place without much difficulty, into the Pelvis, it being small and easily compressed. It descends in the same direction in which it first presents—that is diagonally, like the head—and also rotates, or turns round, so that the left buttock comes in front, just to the right of the pubis, while the right one goes behind, to the left of the sacrum. The left buttock reaches the mouth of the Vulva first, in this position, and then remains stationary there while the right one slides along the curve of the sacrum and perineum, and passes out first at the lower part of the external opening. The left however, speedily follows, and when the whole breech is born it rotates again, one hip coming immediately in front, and the other going immediately behind. Owing to this movement the long diameter of the breech is adapted to the long diameter of the Pelvis, as in the case of the head. This will be evident from the following Plate:—

PLATE XXXII.

Delivery in a breech presentation, the buttocks having just passed the Vulva.

c. The Coccygis, much straightened.
p. The pubic bone, in front.

The rest of the body then rotates in the same way, and the arms and shoulders pass through the external opening in the same direction as the hips. The left shoulder first moves to the right of the pubes, while the left passes behind; and then, just when they are both passing out, one comes immediately in front, and the other immediately behind, placing themselves in the long diameter of the Vulva.

The head passes through the superior strait in the left, anterior occipital position, and is often delivered in that way; but sometimes it rotates, and the forehead passes into the curve of the sacrum, while the occiput is placed behind the pubes. When this occurs the body also rotates, to accompany the head. This state of the parts is represented in the following Plate:—

PLATE XXXIII.

Anterior posterior position of the head, the occiput being in front, after the delivery of the body.

c. The Coccygis.
p. The pubic bone, in front.

At this period the head is passed the uterus, and there is therefore little or no contraction to expel it, so that it often remains a long time undelivered. It will be seen that the position is very unfavorable, the longest diameter of the head, the occipito frontal, being the presenting one, which makes it lie immoveably across. The means of assisting in such a case are plain enough, the forehead must be brought down while the body is raised, towards the mother's abdomen; this will throw the top of the head back, towards the sacrum, and change the presenting diameter. The forehead and bregma rapidly escape below, and the occiput passes out last. This is the way in which nature herself also completes the delivery in such cases, when she has the power.

DELIVERY BY THE BREECH IN THE RIGHT POSTERIOR SACRO ILIAC POSITION.

This position is the reverse of the preceding one, the Sacrum being behind, and to the right, while the Abdomen is to the left in front. The same movements are performed as in the first position, and the whole process is similar, only the reverse way. The Sacrum being behind however, has to rotate much further to come in front, precisely the same as with the head when in the posterior position.

The head generally follows the Sacrum, and the occiput comes under the pubes, as already explained; but sometimes only at the moment when being disengaged.

DELIVERY BY THE BREECH IN THE FULL POSTERIOR, OR SACRO SACRAL POSITION.

In this position there is no rotation at all, the back of the child being turned full to the back of the mother, and the whole body, and head, being expelled in that position. In general there is no particular difficulty from this position, but on the contrary it is thought by some to be rather favorable than otherwise. The longest diameter of the fœtal pelvis, and shoulders, are adapted to the longest diameter of the mother's pelvis, at the upper strait, and easily pass it. They will also generally pass the external opening in the same direction, unless it be very unyielding, or the child very large; and if they pass the head usually follows, because the parts have been so much dilated by the passage of the body that they offer but little resistance.

GENERAL REMARKS ON THE PRESENTATION OF THE LOWER EXTREMITIES.

As a general rule delivery by the breech, or by any other position of the lower extremities, is less favorable than by the head. The labor is usually longer, more painful, and more exhausting; still however, it is generally spontaneous, and not necessarily dangerous to the mother. To the child, on the contrary, it is dangerous, on many accounts.

It appears, from the observations of M. P. Dubois, that in this presentation one child is lost out of every twelve, while only one out of fifty is lost in head presentations! The chief cause for this greater mortality appears to be the compression of the umbilical cord, which is greater, and lasts much longer, than when the head presents, as will be evident on examining the circumstances under which delivery is effected in each case. When the head presents it passes, and also the shoulders, before the umbilicus is reached; the mother's organs are therefore much dilated, and only the smallest parts of the fœtus are left, when the cord is engaged in the passage; it cannot therefore be much compressed, nor for any long time, because the labor is then soon over. When the lower extremities present this is not the case, the smallest parts then pass before the umbilicus is reached, so that the cord has to pass along with the head and shoulders, which are both the largest and the longest in being delivered. This compression of the cord stops the circulation of blood between the fœtus and the Placenta, as will be evident on referring to the description formerly given of Fœtal nutrition; and the stopping of this circulation is as fatal, to it, as stopping the breath is to an adult. When the breech presents altogether, there is not so much danger as with the feet, or knees, because it is large, and in its passage dilates the parts so much that the rest of the body, and the head, follow more quickly. There is, of course, no danger till after the hips have passed, because the cord is not reached before; but the delivery should be completed as soon after they are born as possible, for every minute's delay makes the chances for the child's life so much less.

CHAPTER XIII.

MECHANISM OF DELIVERY IN PRESENTATIONS OF THE FACE.

Presentations of the face appear to result from the head being bent backwards, instead of forwards upon the chest. They are easily recognized, because the face has so many peculiar parts, as the nose and mouth, for instance, which are altogether unlike what can be felt in any other presentation. In a very early stage the forehead may be taken for the vortex, unless care be used, because it feels round and soft like it, but the mistake cannot last long.

The positions in this presentation, as formerly explained, are determined by the chin, and in practice only two are noticed—the right posterior mento iliac, and the left anterior mento iliac. In the first the chin is on the right side, near the sacrum, and in the second it is on the left side, near the pubes. These answer, it will be seen, to the two principal positions of the head itself. It is generally considered that, though the chin, like the head, may assume other positions, yet it does so in but very few cases, and these presenting no peculiarities which require special notice.

DELIVERY IN THE RIGHT POSTERIOR MENTO ILIAC POSITION OF THE FACE.

The head descends with the forehead and chin nearly on a level, and the nose occupying the middle of the passage. When fairly in the cavity it rotates, the chin being brought under the pubes, while the back of the head passes into the curve of the sacrum. This is nearly always the process; no matter where the chin may be when the labor commences, it seldom fails to move under the pubes before it concludes. Occasionally it may rotate the other way, and pass into the hollow of the sacrum, while the occiput comes in front, but this is very rare.

The chin is born first, and then follows, below, the forehead, top of the head, and finally the occiput—the face turning upwards towards the mother's abdomen, as each part is successively delivered. When the head is fully born, the body rotates inside the same as in the head presentation, and the delivery concludes in precisely the same way.

PLATE XXXIV.

Fig. 1.

Fig. 2.

Fig. 1.—The chin just passed, in presentation of the face.

Fig. 2.—The head full born in presentation of the face.—p. The Pubic bone.—c. The Coccygis.

DELIVERY IN OTHER POSITIONS OF THE FACE.

The delivery is precisely the same in all the other positions of the face, excepting that in some of them the chin has further to rotate before it can pass under the pubes. In all cases however, it may be safely calculated that it will do so, there having been so few instances known in which it has rotated the other way, into the hollow of the sacrum, which is fortunate, for there is always more or less difficulty and danger when it does so.

Sometimes the rotation does not take place at all, but the face descends diagonally, as the head occasionally does.

On the whole presentations of the face are not particularly to be feared, as regards the mother. Some authors even consider them quite favorable, and reckon them only as varieties of the head presentation. Madame Lachapelle states as a principle, that face presentations should always be left to nature. And M. Chailly says he must admit that, in all positions of the face, the labor may terminate spontaneously, excepting when the chin passes behind, in which case it will be protracted, and most likely fatal to the child. The labor is generally a little longer, and more painful, owing to the face not being so perfectly adapted to the passage as the head is; but still it must be regarded as favorable to the mother, though assistance is oftener required than with the head. There is more or less danger to the child however, owing to the head being kept under pressure for an unusual time, which produces congestion. The neck is also forced against the pubic bone, as will be seen by Figs. 1 and 2, Plate XXXIV, and thus the jugular veins are compressed. If there be any delay, it is customary to observe the face closely, after the chin is born; and if it appears from any indications that congestion is taking place, assistance is rendered at once. The face will sometimes become so tumefied, and engorged with blood, from this prolonged pressure, that it will not appear natural till several days after birth.

Probably about one child is lost in ten or twelve deliveries in these cases; and if the chin pass behind its death is almost certain.

It was formerly the practice to endeavor to turn the face upwards, when at the superior strait, and so change the presentation to one of the head. This however, is now abandoned, because the attempt is seldom successful, and does not materially improve the condition of things, besides being painful to the mother. The only extra danger with the face presenting is to the child, and this is not removed by the operation; to the mother the face is nearly as favorable as the cranium. In regard to the frequency of face presentations, we find that Madame Lachapelle met with but seventy-two cases in fifteen thousand six hundred and fifty-two deliveries.

CHAPTER XIV.

MECHANISM OF DELIVERY IN PRESENTATIONS OF THE TRUNK.

It has already been stated that in presentations of the Trunk it is nearly always the right or left shoulder which occupies the passage. It is stated, by some authors, that they have felt the back, and abdomen, but others think they were mistaken; and most certainly such positions are extremely rare, if they actually do ever exist.

There are two presentations of the Trunk, determined by the side on which the fœtus lies, and denominated accordingly right or left lateral presentations.

Each of these presentations has two corresponding positions, determined by the side on which the child's head lies. If the head be on the mother's right side it is called the right cephalo iliac position, and if it be on the left side it is denominated the left cephalo iliac position. The mechanism of spontaneous delivery is the same in them both, and in all their varieties, and so is the mode of rendering assistance, so that a description of one will suffice.

Sometimes, when the labor has lasted long without assistance, one arm will be forced down first, and even appear externally. This used to be considered a separate presentation, and described as such, under the name of presentation of the hand and arm. There is no reason for describing it separately however, and no utility in doing so, as it differs in no essential particular from ordinary presentation of the shoulders, and must receive the same assistance.

What it is that produces presentations of the Trunk, and other unfavorable parts, is not known, though they are generally thought to be owing to excessive motion in the child, or obliquities of the Womb.

M. Lachapelle met with sixty-eight cases of Trunk presentation in fifteen thousand six hundred and fifty-two labors, which is nearly the same as the face. The right side presents more frequently than the left, and the head is on the left side oftener than on the right, as it is in ordinary head presentations.

As a general rule assistance is always rendered in presentations of the Trunk, and is generally considered absolutely necessary. It is undoubtedly true however, that nature has effected delivery in such cases unaided, though rarely, and such instances are considered as extremely fortunate exceptions to the general rule. M. Chailly says that the accoucheur should never leave such cases to nature alone, but always aid her; but other authors trust to her a little more. The most usual mode of rendering assistance is to turn the child, and bring down the feet, a manœuvre which will be fully described hereafter.

In some cases the child turns itself, from the contractions of the Womb, before it enters the upper strait; and in other cases, when very small, or long dead, it will pass folded double. This self-turning however, cannot take place after the escape of the waters, so that it seldom occurs when the membranes are broken.

MECHANISM OF DELIVERY IN PRESENTATIONS OF THE TRUNK BY SPONTANEOUS EVOLUTION.

This is the most usual mode for the fœtus to escape, in each presentation, and in every position. By referring to the following Plates, and the accompanying descriptions, it will be readily understood.

PLATE XXXV.

Position of the Fœtus in a presentation of the right shoulder, and in the left cephalo iliac position.

Previous to the rupture of the membranes the child's body lies across, as formerly explained; but immediately after the rupture the shoulders descend into the Pelvis, as seen in the above Plate, while the head remains above the pubes; the arm frequently, but not always, protruding externally.

The shoulder then continues to descend, the body following, bent up against the face, as seen in Plate XXXVI.

PLATE XXXVI.

Descent of the shoulder in a Trunk presentation, at a more advanced period.

Here the shoulder is protruded from the Vulva, the back being nearly folded, and the knees turned up against the face.

PLATE XXXVII.

Descent of the shoulder and trunk at a still later period.

The whole Trunk is now fully delivered, folded almost double, and the legs and feet are turned up against the face. They speedily follow however, and then nothing is left but the head, and perhaps one or both arms, placed against the sides of it, as shown in Plate XXXVIII.

PLATE XXXVIII.

The Trunk has fully descended, and only the head is left, with one arm.

The arm is generally very easily brought down, or it may remain and come with the head. The delivery of the head is effected the same as in presentations of the pelvis, and is seldom attended with much difficulty, the parts having been so much distended. The body always rotates so that the back comes in front, and the chin passes into the curve of the Sacrum.

This is the way in which the delivery is effected by nature in such cases, and it will readily be conceived how dangerous it is to both mother and child, and how seldom it can be accomplished. If the Fœtus be of a full size, and the mother's pelvis no larger than ordinary, it is almost impossible for this spontaneous evolution to take place; and even when it does, it is with the greatest difficulty, the mother suffering in an extreme degree, and running great risk, not only of the most serious after results, but even of death. To the child the danger is equally great, owing to the severe and long-continued compression it receives, and the unnatural position it assumes. M. Velpeau tells us that in one hundred and thirty-seven such cases, one hundred and twenty-five of the children died. The number of the mothers also, who either died or were made sufferers all their future lives, was undoubtedly great, though unknown.

It is evident therefore, that presentations of the Trunk are the most unfavorable known, and labor in them is but rarely spontaneous. Nature can but very seldom effect the delivery of the Fœtus herself, and even when she does it is with the greatest risk, both to it and the mother. The accoucheur should always assist therefore, if he can, because even if nature can complete the delivery it is with such danger. The means of assisting, by turning, will be described in another Chapter.

If the fœtus is not at full term, and of course is under the full size, its expulsion may be left to nature safely, but not otherwise.