Part 14 (2/2)

Such are the two positions in which the head presents during labour, and such is the manner in which it pa.s.ses through the pelvis and external pa.s.sages. Slight deviations do occasionally take place, the chief of which is, that the head in the second position does not always make the quarter of a turn as above described, but comes out with the anterior fontanelle forwards and to the left: this is by no means of common occurrence, and, as far as we have observed, increases the difficulty of labour very little.

_Face presentations._ The face, like the cranium, may present in two ways, either with its right or left side forwards. The former is the most frequent occurrence, and bears a striking a.n.a.logy to the first cranial position; indeed, we cannot too strongly impress upon the minds of our readers the advantages of accurately knowing the different features of the two cranial positions just described; for by this means the positions of the face will be rendered much more simple and easy of comprehension.

Whether the right or the left side of the face presents (first or second facial position,) the root of the nose crosses the os uteri exactly in the same manner as the sagittal suture does in the two cranial positions; the chin is turned to the right acetabulum, and as the face descends through the pelvis during the progress of the labour, the chin moves somewhat more forwards, as the occiput does in the cranial positions.

At an early stage of labour the right eye and zygoma is that part of the face which is lowest in the pelvis, and which the finger first touches upon during examination, precisely as it was the right parietal protuberance in the first cranial position; and as in this case the caput succedaneum was situated upon the posterior and superior quarter of the right parietal bone, so here the livid bruise-like swelling, which the face brings with it into the world, is situated upon the right cheek, this part being the first which presses through the os externum; the chin pa.s.ses under the right branch of the pubic arch, as the occiput in the first cranial position does under the left, the face during the whole process preserving a strictly oblique position, both as to the transverse diameter and axis of the pelvis.[78]

_Second position of the face._ The second position of the face is merely the reverse of the first: it is now the left side which is turned forwards, the left eye and zygomatic process being those parts which are lowest in the pelvis; the chin is turned to the left side and somewhat forward, and advances towards the left foramen ovale during the farther progress of the labour. As the face approaches the inferior aperture of the pelvis, it is the left cheek which first enters the os externum, and upon which the swelling is situated: likewise the chin pa.s.ses beneath the left branch of the pubic arch.

It has been supposed by some authors, and we think correctly that the majority (if not all) of face presentations are originally cranial presentations: if this be the case, we can easily understand why the right side of the face presents more frequently than the left, for if the head in the first cranial position moves round upon its transverse diameter, and thus allows the face to turn downwards, we shall immediately have a first position of the face. We are the more inclined to adopt this opinion, not only from the greater number of cases where the right side of the face presents, but also from our having more than once met with cases where so long as the head of the child was moveable above the brim, the presentation was midway between one of the cranium, and of the face. On one side of the pelvis we could feel the anterior fontanelle; on the other we could, with some difficulty, reach the orbital process of the frontal bone: as the pains increased, and the head advanced lower, the side of the face came more within reach; so that by the time it had fairly entered the cavity of the pelvis, it had become a complete presentation of the face.[79]

We distinguish the face by the bridge of the nose, which from its crossing the os uteri may be detected at a very early period of labour: it is far better than the eye, for not only is this liable to mislead us in our examination, but it may also receive injury from the finger. Nor is the malar bone a guide, for this might easily be mistaken for the tuberosity of the ischium, or even for the shoulder. The nose not only tells us that the face is presenting but also in which position, for at one end we shall feel the soft cus.h.i.+ony extremity of it, at the other we shall reach the broad hard expanse of the forehead.

It was not until nearly the end of the last century that presentations of the face ceased to be accounted unnatural, and impossible to be terminated by natural means. Although the fact had been pointed out by Portal so early as 1685, that these presentations were very little removed from the usual one, it seems to have excited but little attention until the time of Deleurye in 1770. ”I have,” says Portal, ”delivered several women whose children came with the face foremost, and always without any great difficulty, it being only observed, _that in such cases no violence must be used, but nature be left to its own course; which done, there is no danger either of mother or child_.” (Portal's _Midwifery_, transl. obs.

66:) La Motte in 1721, although so accurate an observer, could not divest himself of the general opinion that these were unfavourable positions, even although the face was usually expelled by the natural efforts, after he had fruitlessly endeavoured to rectify it, and although he himself confesses never to have ”seen any that had not done well.”

Giffard has recorded two cases of face presentation (_Cases in Midwifery_, 1734, p. 59, 443.,) both of which he delivered by his extractor, which was one of the early forms of midwifery forceps; and in both, although the labour had lasted some time, the child was alive. He describes the position of the face in the second case, the chin being turned towards the right side. The only practical observation which he makes is, that turning is very difficult where the ”waters are gone off, and the uterus closely envelopes the child.” This is probably given as an explanation for his deviating from the usual practice of turning in these cases. Deleurye in supporting Portal's views observes, ”one daily sees similar labours terminate naturally: it is true they are somewhat longer, but they terminate without the aid of art.” (_Traite des Accouchemens_, 1770, -- 736.)

Lastly, the celebrated Boer of Vienna (1793) placed the matter in a still more decided point of view when he a.s.serted, that ”face presentations being merely a rare form of natural labour, should be left to be completed by the natural efforts, since neither the mothers nor their children were exposed to any more danger in this form of labour than they were in the most usual forms of all.” Having charge of the great lying-in hospital of Vienna, Boer had ample means of ascertaining the most accurate results on all points of practical midwifery, and his observations on labours where the face presented, are, therefore, peculiarly interesting, and tend strongly to contradict the prevailing opinion respecting the difficulty and danger of these presentations.

”Of eighty cases of face presentations which have occurred during a period of some years, and which I have myself observed and noted down, there were three, or at the most four, where the children were born dead. None of the patients suffered in the slightest degree from any of these labours; and, except one case, all were left entirely to nature: in one case only, on account of the weakness of the pains and doubtful character of the symptoms, I deemed it necessary to terminate the labour by the forceps.” (Boer's _Naturliche Geburtshulfe_, erstes buch, p. 137.) In spite of this valuable practical fact, supported by experience on so great a scale, the opinion that face presentations were preternatural, continued to prevail upon the Continent, being supported by the authority of Baudelocque and Osiander. A similarly unfavourable opinion was entertained by Dr. Smellie in this country, although Dr. W. Hunter, in his lectures delivered prior to the publication of his plates on the gravid uterus (and, therefore, at an early date,) states, ”in this case I do not turn the head round in order to deliver, but nineteen times in twenty leave it to itself to come as it will.” (W. Hunter, _MS. Lectures_.)

Dr. R. W. Johnson, who dedicated his _New System of Midwifery_, &c. to Dr.

W. Hunter and others, in 1769, and probably attended his lectures, expresses a similar opinion, and says, that in these cases ”nature herself will do the work.” (p. 267.) Dr. Alexander Hamilton, in 1784, also speaks favourably of these presentations. ”The head will, however, in most cases, advance in that position by the force of the natural pains, though the delivery will be more slow or painful.” (_Outlines of the Theory and Practice of Midwifery._)

Farther experience has shown that, so long as the pelvis is of the natural size, the head can be born in this position without peculiar difficulty, the soft parts usually require a little more dilatation than where the cranium presents, and, therefore, this stage of the labour is generally somewhat slower. Although presentations of the face are not so favourable for the child as those of the cranium, they stand next to them in point of safety. Where the cranium presents, a slight misproportion between the head and pelvis produces little or no increase of difficulty to the pa.s.sage of the child; but under similar circ.u.mstances, where the face presents, the difficulty may become very serious, for if the labour is prolonged, ”the brain and vessels of the neck,” observes Smellie, ”will be so much compressed and obstructed as to destroy the child.” (Explanation to table 25.) A similar view has been given by Dr. Denman, and still more recently by Professor Chaussier, of Paris, and Professor Naegele; the two latter authorities examined the brain in several still-born children where the face had presented, and invariably found the cerebral vessels gorged with blood.

The presenting side of the face when born is frightfully distorted by the livid swelling above-mentioned; the mouth is pulled to one side and upwards; the angle of the eye is drawn downwards, and the corresponding ala of the nose scarcely discernible amid the purple ma.s.s of tumefaction: the less this is meddled with the better, for in the course of a day or two the parts will have returned to their condition; whereas, if friction or hot poultices, &c., be used, ulceration may be the result, and produce considerable disfigurement.[80]

_Nates presentations._ ”After the presentations of the cranium those of the nates are the most frequent in point of occurrence, and also the most natural,” says the celebrated Boer, in the work already quoted. Under the term _nates_ presentations, we include those of the knees and feet, as these latter presentations can only be looked upon as modifications of the former. Professor Naegele, jun., in his new edition of the admirable essay upon the mechanism of labour, published by his father, in Meckel's _Archiv. fur die Physiologie_, has very properly brought these different positions under one head, viz. ”positions of the pelvic extremity of the child:” as, however, we possess no word in English to express this, we shall attain the same object by considering knee and footling births as mere modifications of breech presentations.

”As regards the relative situation of the limbs to the body of the child, the position is the same as in the two genera of head presentations above described, viz. the knees are usually drawn up to the abdomen, the feet close to the nates, so that not unfrequently they may both be felt together at the beginning of labour, and afterwards descend into the pelvis and are born together. Sometimes the feet (or perhaps only one foot) are felt higher above the brim than the nates; in which case, as the nates descend they rise, and are turned upon the abdomen and breast of the child, and descend with these parts as labour advances. Frequently it is the reverse: the feet are somewhat lower than the nates; they are felt in the os uteri at the beginning of labour, and descend before them as labour advances. It is rare that the knees come down before the nates during the farther progress of labour, and it is not probable that they are ever found alone in the os uteri at the commencement of it.” (H. F. Naegele, _Mechanismus der Geburt_, 1838, p. 57.)

The nates may present in two ways, either with the back of the child forwards, or with its abdomen forwards: of these the former occurs most frequently; thus of 161 cases which were accurately ascertained at the lying-in hospital of Heidelburg, 121 were observed with the back of the child forwards, and 40 with it backwards: in either of these positions the transverse diameter of the child's pelvis always corresponds to one or other of the oblique diameters.

”Labours with the nates or feet presenting, follow certain laws quite as much as those where the head presents, only that one more frequently sees deviations from them, both with respect to the manner in which the child presents at the time of labour, and its pa.s.sage through the pelvis; but where, under a proper state of the other requisites for healthy parturition, no prejudicial result occurs.” (Naegele, _on the Mechanism of Parturition_, transl. -- 19. p. 128.) ”In every case, whether the nates have at first a completely transverse or oblique direction, they will be always found, on pressing lower into the superior aperture of the pelvis, to have taken an oblique position; and that ischium, which is directed anteriorly, to stand lowest. They pa.s.s through the entrance cavity and outlet of the pelvis in this position, which is oblique, both as to its transverse diameter as well as to its axis.”

Thus, if in the first species the left ischium were either originally directed more or less forward, (which is usually the case,) or had taken this direction in pa.s.sing through the superior aperture, the nates descend in this direction into the pelvic cavity, with the left ischium during the whole time standing lowest; and this is the part, during the farther progress of the nates, which first pa.s.ses between the l.a.b.i.a as the os externum dilates. As they advance, and while the left ischium, which is directed forwards and always somewhat to the right, comes completely under the pubic arch and presses against it, the other ischium, which is situated in the opposite direction, and which has to make a much greater circuit, pa.s.ses forwards over the strongly distended perineum, so that, when the pelvis is born, the abdomen of the child will be directed to the inner and posterior surface of the mother's right thigh.

”The rest of the trunk follows in this position, and as the breast approaches the inferior aperture of the pelvis, the shoulders press through its superior aperture in the direction of the left oblique diameter; and during its pa.s.sage (viz. the breast) through the pelvic outlet, the arms and elbows which were pressed against it are born at the some moment. But whilst the shoulders are descending in the above-mentioned oblique position, the head, which during the whole progress of the labour rests with its chin upon the breast, presses into the superior aperture in the direction of the right oblique diameter, (viz. with the forehead corresponding to the right sacro-iliac synchondrosis,) and then into the cavity of the pelvis in the same direction, or one more approaching the conjugate diameter. After this, it presses through the external pa.s.sage and the l.a.b.i.a, in such a manner, that whilst the occiput rests against the os pubis, the point of the chin, followed by the rest of the face, sweeps over the perineum as the head turns on its lateral axis from below upwards.

”But it is sometimes the right ischium, which, in this chief division, is either originally turned forwards, or in the process of time a.s.sumes this direction. In this case the child pa.s.ses through the pelvis in the same manner as before, only with the difference, that the surface of the body takes of course a different position with respect to the pelvic parietes, viz. its anterior surface, which in the former case corresponded to the right side of the pelvis, will be directed to the left, and the head will press through the superior aperture of the pelvis, in the direction of the left oblique diameter (the forehead pa.s.sing before the left sacro-iliac synchondrosis.)”

”As in positions of the cranium, the swelling of the integuments is chiefly met with on that parietal bone which during the pa.s.sage of the head, is situated lowest, and on that spot with which it enters the external pa.s.sage, so in this case the livid coloured swelling appears on that part which, directed forwards, was situated lowest during the pa.s.sage of the nates, and with which the nates were born.

”In the second chief position, viz. with the anterior surface of the child corresponding to the anterior abdominal parietes of the mother, it is chiefly the left ischium which is either originally situated forwards, or takes this direction as the nates sink through the superior aperture of the pelvis, which latter preserve this oblique direction during the farther progress of the labour, both whilst pressing into the pelvic cavity, and when entering the external pa.s.sages.

”If the ischia be already born, the anterior surface of the child turns itself to the right and backwards, either immediately, or as the rest of the trunk advances; but the manner in which the head in this case presses through the entrance cavity and outlet of the pelvis, is the same as has already been described.” (Naegele, _op. cit._ p. 128, 130.)

<script>