A System of Midwifery Part 21

Where the head is very large, the bones are seldom much ossified; they therefore yield easily, and the head accommodates itself to the shape of the pa.s.sage: sometimes, however, it is unusually hard, the bones are well ossified and very unyielding, so that even if it be not larger than common, still, from its hardness, it meets with considerable difficulty in pa.s.sing through the pelvis. Cases have been described where the cranial bones were completely ossified, and the sutures perfect; but this latter is very doubtful. Perfect mentions an instance where the head was "almost one entire ossification, and where it pa.s.sed through the pelvis with great difficulty." (Perfect's _Cases in Midwifery_, vol. ii. p. 370.) We have also met with cases requiring perforation on account of deformed pelvis, and where the cranial bones had almost the feel of a hard nut or sh.e.l.l; still, however, as already observed, we seldom see any serious impediment to the pa.s.sage of a large head, so long as it is naturally formed; and this applies also to the other parts of the child.

_Form of the child._ On the other hand, where there is an unnatural form of the child, either from a disproportionate size or anormal configuration of certain parts, labour may be rendered not only very difficult but dangerous: thus one of the three great cavities may be distended with an acc.u.mulation of fluid, the most common form of which, is the congenital hydrocephalus.

_Hydrocephalus._ In many cases it produces much less resistance than might be expected from the size of the head; this is, in great measure, owing to the unusual width of the sutures and fontanelles, but chiefly to the almost entire want of ossification in the cranial parietes, which are little else than membranous, and so flexible as to allow the head to be squeezed into almost any shape. In some very rare cases the head has burst, a large quant.i.ty of fluid has come away suddenly, and this has been followed almost immediately by the birth of the child:[115] but in the majority the labour has been tedious and severe, and in some instances attended with dangerous results to the patient; thus, Dr. Merriman has "known one hydrocephalic foetus pa.s.s entire, the circ.u.mference of whose head was 17 inches; another pa.s.sed alive and lived nearly an hour, whose head measured in circ.u.mference nearly 22 inches; both the above labours were long and painful." Perfect relates a case of hydrocephalic head, of which he has given engraved delineations; the labour was attended with extreme difficulty, and the woman expired in less than two hours after delivery; the circ.u.mference of this head was 24 inches. (_Cases in Midwifery_, vol. ii. p. 525.) An interesting case of hydrocephalus, attended with convulsions and laceration of the v.a.g.i.n.a, has been recorded by Dr. Collins: "the perforator was used, upon the introduction of which into the head fully three half pints of water gushed out; the bones then collapsed, and the delivery was easily completed." (_Practical Observations_, p. 205.)

_Cerebral tumours._ The bulk of the head is sometimes increased by tumours or sacs of fluid, which arise from a suture or fontanelle: they are of the same nature as the spina bifida, being formed by a protrusion of the integuments and cerebral membranes from an acc.u.mulation of fluid beneath: these are of very rare occurrence, and appear to have r.e.t.a.r.ded labour but little, even although of considerable size. The largest cases on record are those which have been described by Ruysch, where one was as big as the head itself, and another where it was nearly as large as the child's body.[116] A case of fluctuating tumour upon a child's head has been described by Mauriceau, (Case 544,) but the precise nature of it is not very apparent.

_Acc.u.mulations of fluid, and tumours in the chest or abdomen._ It is very rare that the chest is distended by any acc.u.mulation of fluid or morbid growth, although this is not unfrequently met with in the abdomen. La Motte has given three cases of ascites which, by the distention of the abdomen, produced considerable obstruction to the delivery of the child.

(Cases 331, 332, and 333.) In other cases the liver or the kidneys have been enormously enlarged. A case is described by Dr. Hemmer, where the child was born as far as the shoulders, and there stuck; finding it impossible to extract the child, he perforated the abdomen in two places, but could not extract it; in a few minutes after it came away of itself.

The abdomen had been distended with small hydatids; these gradually escaped, and thus diminished the size of the abdomen. (_Neue Zeitschrift fur Geburtshulfe_, band iv. heft 1, 1836.) Where the child has been dead some time in the uterus, the abdomen is frequently tympanic, and thus r.e.t.a.r.ds its expulsion.

_Monsters._ Certain cases of monstrous formation may produce very serious obstacles to the progress of labour: the most considerable is of twins united by the breast. It is difficult to conceive how so large a ma.s.s can be forced through the pelvis: we can only suppose it possible where the children have been dead some time before birth, or where they were premature: to this latter circ.u.mstance only we can attribute the fact of their having been born alive, as in the celebrated case of the Siamese twins. Where the children have been united by one pelvis, &c., the chances here of the foetus being dead before birth would be even still greater. M.

Rath, of Zetterfeld, has lately described a case of extremely difficult labour, in consequence of twins united by the breast. "The children (two girls) weighed 15lbs.; they were 17 inches long. The part by which they were united was 9 inches broad and 3 long, and extended from the upper extremity of the sternum to the navel, into which one umbilical cord, which was common to both, entered. The diameter of the two children when laid together was between 7 and 8 inches from one back to the other. One child had two thumbs on the right hand. The cord was 19 inches long, and unusually thick. After suffering some time from peritonitis, &c., the patient recovered." (Siebold's _Journal_, band xvii. heft 2. 1833.)

_Anchylosis of the joints of the foetus._ Lastly, we may mention a very rare cause of this species of dystocia, which has been observed by Professor Busch, where the obstruction to the pa.s.sage of the child arose from anchylosis of its joints. "The head had been delivered by the forceps, but the body would not follow. As no cause of obstruction could be discovered, a gentle and then more powerful traction was used: this was followed by a cracking sound, and the upper part of the trunk pa.s.sed through the os externum: here again it stopped, but still, as no cause of obstruction could be discovered, and as the child was dead, another traction was made, with a repet.i.tion of the cracking sound, and the child was delivered. On examination it was found that all the joints of the extremities were anchylosed in the usual position of the foetus in utero, so that the ossa humeri and then the ossa femoris had given way. The child had been dead some time." (_Neue Zeitschrift fur Geburtskunde_, vol. xv.

1837; and _British and Foreign Med. Rev._ April 1838, p. 579.)

No precise rules can be given for the treatment of these cases of malformation of the child; it must be modified according to the peculiarities of each individual case. Whenever a part has undergone considerable increase of size from acc.u.mulation of fluid, this can be in most cases removed without much difficulty by perforation, whether it be of the head or abdomen. With monstrous growths the accoucheur must depend upon his own resources, ingenuity and knowledge of the mechanism of parturition. The more careful and correct his diagnosis is, the more efficient will be the means he adopts for delivering the child. In such cases the examination can scarcely be made effectually by the finger alone, but the hand will be required for this purpose.

CHAPTER III.

THIRD SPECIES OF DYSTOCIA.

_Difficult labour from faulty condition of the parts which belong to the child.--The membranes.--Premature rupture of the membranes.-- Liquor amnii.--Umbilical cord.--Knots upon the cord.--Placenta._

In describing this species of dystocia, according to the arrangement of Professor Naegele, which we have adopted, it will be necessary to observe that serious obstructions to the pa.s.sage of the child is seldom produced by it, although, at the same time, many slight derangements in the progress of labour are liable to result, which demand the care of the pract.i.tioner.

The membranes when too thick or tough (Merriman's _Synopsis_, p. 217,) may r.e.t.a.r.d the labour occasionally, especially during the second stage, when instead of bursting and allowing the uterus to contract more powerfully upon the child by the evacuation of the liquor amnii, they are pushed down into the v.a.g.i.n.a, forming a large conical sac, which may even protrude externally. We doubt much, however, if the non-rupture of the membranes at the proper time during labour is of itself sufficient to r.e.t.a.r.d its progress, for it is frequently observed that the head will, nevertheless, advance rapidly and even be born covered by the protruded membranes. Where labour is rendered tedious by the unusual strength of the membranes, it is generally connected with considerable distention of the uterus from liquor amnii; in which case the bag of waters is so spherical that it will not descend readily into the v.a.g.i.n.a, even although the os uteri is fully dilated, and, therefore, prevents the advance of the head: to this we shall recur immediately. So long as there is no undue acc.u.mulation of liquor amnii, we may safely allow the membranes to descend to the os externum before we rupture them. In former times a variety of instruments were employed for this purpose, many of which were dangerous, and all unnecessary, the finger being in most cases sufficient. The most effectual way of doing this is to press the thumb and middle finger upon the membranes during a pain and thus increase their tension, whilst the point of the fore-finger is pushed against them: scratching them with the nail during a pain will be sufficient when they are higher up the v.a.g.i.n.a.

_Premature rupture of the membranes._ More frequently the membranes rupture too soon, that is, before the os uteri is fully dilated: this may arise from their being too thin, a condition, however, which it is not very easy to prove: in most instances, it is observed where the uterus is but moderately distended, and where it has that oval or pyriform shape which we have already pointed out as being best adapted for acting efficiently upon the os uteri. This, perhaps, is one reason, why too early rupture of the membranes so frequently occurs in primiparae; and this may be one cause, among many others, why first labours are generally so much more tedious and severe. The membranes may also be prematurely ruptured by violent exertions, coughing, sneezing, vomiting, &c. by straining immoderately and too soon, by rough and awkward examination, &c. Where this is the case, the patient should preserve the horizontal posture, and keep as quiet as she can until the os uteri has dilated sufficiently and allowed the head to advance.

_Liquor amnii._ Where the uterus is distended by an unusual quant.i.ty of liquor amnii, its contractile power is necessarily much impaired; and until the quant.i.ty of its contents be somewhat diminished, the progress of the labour will be more or less r.e.t.a.r.ded. The average quant.i.ty of liquor amnii at the full period of pregnancy is about eight ounces; but it frequently exceeds this very considerably, occasionally amounting to several pints or even quarts. The causes of this extraordinary acc.u.mulation are still but little known. "M. Mercier has, in some cases, attributed it to an inflammatory condition of the amnion, the foetal surface of this membrane being stated to have been partially coated with false membrane, and the amnion itself crowded with blood-vessels of a rose colour:" in another case "about a quarter of the foetal surface of the amnion was inflamed, being of a deep red colour and double the natural thickness."[117] The results of Dr. R. Lee's observations, after having paid a good deal of attention to the subject, do not tend to confirm this view: he has described six cases of unusual acc.u.mulation of the liquor amnii, in one amounting actually to sixteen pints. In five of them "there existed with dropsy of the amnion some malformed or diseased condition of the foetus or its involucra, which rendered it incapable of supporting life subsequent to birth." In two only of the preceding cases was "the formation of an excessive quant.i.ty of liquor amnii accompanied with inflammatory and dropsical symptoms in the mother; and in none did the amnion, where an opportunity occurred for making an examination, exhibit those morbid appearances produced by inflammation, which M. Mercier has described, and which led him to infer that inflammation of the amnion is the essential cause of the disease." (Lee, _op. cit._) Dr. Merriman has given a similar opinion, and states, that "when the embryo or foetus is diseased, the liquor amnii is sometimes immense in quant.i.ty. I once saw at least two gallons evacuated from the uterus: the child was monstrously formed and much diseased."[118]

In these cases the size and globular form of the uterus, the tenseness of its parietes, the more or less distinct feel of fluctuation, the absence of the child's movements and of any prominences arising from the projecting portions of its body, the rapid increase which has been observed in the size of the abdomen, the pain in different parts of the uterus, especially in the groins and pelvis, the oedema or anasarca of the lower extremities, serve to mark this condition. On examination per v.a.g.i.n.am we also feel the inferior segment of the uterus much expanded, the cervix probably shorter than might be expected for the period of pregnancy; the ballottement is unusually free and distinct. In some instances the patient has suffered so much, either from the effects of the r.e.t.a.r.ded circulation in the lower extremities, or from the impeded respiration as to require the membranes to be punctured in order to reduce the size of the uterus. The child is usually born dead where the acc.u.mulation has gone to so great an extent: in the three cases recorded by La Motte, it was dead before birth in the first two, and died immediately after birth in the third. Many of these cases, which have been complicated with disease or malformation of the foetus, have appeared to arise from a syphilitic taint; but in others, of more common occurrence, where there was merely an unusually large quant.i.ty of liquor amnii without any disease either of the mother or her child, the cause must still remain a matter of uncertainty. This latter condition is mostly seen in women who have been frequently pregnant; the os uteri in them is generally yielding, and when once it has attained its full degree of dilatation, we may safely rupture the membranes and thus expedite labour considerably.

There being an unusually small quant.i.ty of liquor amnii can scarcely operate as an obstruction to labour, except where the membranes have been prematurely ruptured.

The _umbilical cord_ may obstruct labour, by either being too short, or rendered so from being twisted round some part of the child. Its length varies very considerably. Although we have stated it to average about eighteen or twenty inches,[119] we have met with extreme deviations both within as well as beyond this medium length. The shortest cord which we know of occurred some years ago at the General Lying-in Hospital, "where, after two or three violent pains, the child was suddenly and forcibly expelled the cord was found ruptured at about two inches from the navel of the child, which cried stoutly. After removing the child the matron sought for the other end of the funis, but could not find it; she examined per v.a.g.i.n.am but could not feel it; and on introducing her hand into the uterus, found the placenta with the remains of the cord ruptured at its very insertion; so that in this case the cord could not have been much more than two inches long." (Printed Lectures in Renshaw's _Lond. Med. and Surg. Journ._ May 1835, p. 426.)

We quite agree with Professor Naegele, that unusual shortness of the cord can rarely if ever r.e.t.a.r.d labour; and that where the cord really produces an impediment to its progress, it is from being twisted round the neck, or some other part of the child. (_Lehrbuch_, 2d ed. p. 289.) This generally arises from its unusual length, and from its having formed several coils around the child: we have met with it forty-eight inches long, and twisted four times round the child's neck; but Baudelocque mentions a case where it actually measured fifty-seven inches, "forming seven turns round the child's neck." (Heath's _Transl._ vol. i. -- 516.) Mauriceau has given an instance (_Obs._ 401.,) where the cord had "longueur d'une aune et un tiers de notre mesure de Paris:" which, converted into English measure, amounts to somewhat more than sixty-one inches.

Although nothing is of more common occurrence than the cord being twisted once or twice round the child, it nevertheless, happens, but very rarely, that its advance is thereby obstructed. In a case of this sort, the labour usually commences quite favourably; the os uteri dilates, and the head advances to a certain extent, beyond which it makes no other farther progress; the uterine contractions are attended with much pain in the fundus, during which the head advances somewhat, but retires again during the intervals. Where the head is already near the os externum, this may be easily attributed to the elasticity of the soft parts, until the delay which takes place to the farther progress of the labour warns the pract.i.tioner that something more than ordinary is the cause. But where this takes place, and the head is still in the pelvic cavity; where at the same time, although it refuses to advance, it is quite moveable, and allows the finger to be pa.s.sed freely round it; where any attempt to extract it with the forceps has not only met with great opposition, but has greatly aggravated the sense of painful dragging in the upper parts of the uterus there will be pretty certain evidence of the cord being either too short, or, what is most probable, of its being twisted round the child. In each of the three cases recorded by La Motte, the head had descended to the os externum; whereas, in two others described by Burton, it was evidently much higher up: he ruptured the cord in both instances; La Motte succeeded in cutting the cord with a pair of scissors in one case, in another he appears to have separated the placenta, and in the other to have delivered by little else than force. Where upon introducing the hand we find it impossible to undo the coil of the funis, we should endeavour to slip it first over one and then the other shoulder, as we have recommended under the more ordinary circ.u.mstances: should this fail, we must try to cut it through either by a finger nail slightly notched for the purpose, or by the introduction of a Smellie perforator well guarded.

The cord being twisted round the child's neck may not only r.e.t.a.r.d labour, it may destroy the child itself by preventing the free return of blood from the head: this may take place some little time before birth, or during the actual process of labour. That suffocation cannot possibly be the cause of death under these circ.u.mstances is sufficiently evident.

_Knots upon the cord_ have been mentioned by some authors as a cause of danger to the child shortly before and especially during labour; for the circulation in the umbilical vessels being more or less compressed, the child would either be born dead or in a very weakly state. Experience has, however, shown that these effects have been much over-rated, and that these knots are seldom injurious to the child.[120] Baudelocque has not only met with single, but even triple and very complicated knots tied tightly upon the cord, and yet the child was not only born alive, but remarkably robust and healthy. Circ.u.mstances, however, may occur by which the knot is gradually drawn so tight as to destroy the child. Smellie has given a case of this kind; but it is to the late Matthew Saxtorph, of Copenhagen, that we are indebted for an admirable essay on this subject.

The result of his observations coincides with those of Baudelocque, viz.

that it rarely proves fatal to the child.[121] The manner in which these knots are formed may be easily imagined; when by chance the cord lies in the form of a ring, and the foetus happens to float through it, a noose is made, which, when drawn tight by accident, forms a knot.

The most favourable time for the formation of such knots is in the earlier months of pregnancy, when the quant.i.ty of liquor amnii, in proportion to the bulk of the foetus, is so much greater than at an after period, and when its movements are consequently less impeded. The circulation in the knot will be obstructed in proportion as the knot is drawn closer: if it be merely somewhat impeded, the vessels on each side of the knot will be distended and varicose, and the cord itself, where it forms the knot, from the constant gradual pressure of one fold against the other, will become more or less flattened.[122] We believe that in every case the cord has been of unusual length.

The _placenta_ cannot easily obstruct the birth of the child, although it may render the labour exceedingly dangerous in a great variety of ways: these circ.u.mstances will be considered under their respective heads.

CHAPTER IV.

FOURTH SPECIES OF DYSTOCIA.

_Abnormal state of the pelvis.--Equally contracted pelvis.--Unequally contracted pelvis.--Rickets.--Malacosteon, or mollities ossium.-- Symptoms of deformed pelvis.--Funnel-shaped pelvis.--Obliquely distorted pelvis.--Exostosis.--Diagnosis of contracted pelvis.-- Effects of difficult labour from deformed pelvis.--Fracture of the parietal bone.--Treatment.--Prognosis._

This may arise from there being either too much or too little resistance to the pa.s.sage of the child; where, in the one case, labour is rendered difficult or impossible to be completed by the natural powers; in the other, it is unnaturally rapid. The latter condition belongs to the second great division of dystocia, where the faulty character of the labour does not depend upon its progress being deranged, but upon other circ.u.mstances: we shall, therefore, delay speaking of precipitate or too rapid labour from unusually large pelvis, until then, and devote the present chapter to the consideration of those cases where the labour is more or less obstructed by the faulty condition of the mother's pelvis.

The pelvis may obstruct the pa.s.sage of the child in a variety of ways.

1. It may be merely a diminutive or dwarfish pelvis, viz. well formed but smaller than usual in every direction--the pelvis simpliciter justo minor of Continental authors.

2. It may be distorted and deformed.

3. It may be of the natural form and size, but the pa.s.sage through it more or less obstructed by exostosis.

_Equally contracted pelvis._ The first species of faulty pelvis (_pelvis simpliciter justo minor_,) is not of common occurrence, and has received but little notice in this country. It has been said to resemble the pelvis of a girl in its general appearance; but this only holds good in point of size; for, in the relative proportions of its diameter, it presents all the characters of a well formed adult pelvis. From this circ.u.mstance, it can scarcely be said to be an arrest of development, the necessary changes in the form of the pelvis having taken place at the time of p.u.b.erty, as completely as if it had been of the ordinary size. A pelvis of this sort may be not more than a quarter of an inch too small in every direction, or it may be as much as a whole inch: we do not know of any case where the diminution has exceeded this last degree.

The pelvis equaliter justo minor is not accompanied with a corresponding diminutiveness in the rest of the skeleton, most of the patients in whom it has been observed being well formed and of the usual stature.

Fortunately, as before stated, it is of rare occurrence, for even a small diminution in the size of the bony pa.s.sages, which is uniform in _every direction_, presents a most serious obstacle to the pa.s.sage of the child.

Thus, in three cases of the sort, which have been described by Professor Busch in his report of the Berlin Lying-in Hospital, the labour terminated fatally in two. "The first case was a presentation of the breech; the head was delivered by the forceps; the child was dead; the pelvis measured half an inch too small in every direction. In the second case, which was a head presentation, the delivery was effected by the forceps, but not without the greatest efforts; the child was still-born, and the mother died in a day or two after from peritoneal inflammation. The third case required perforation; this also terminated fatally, the forceps having been previously applied, and considerable efforts made without success. On examination after death, every diameter of the pelvis was three quarters of an inch smaller than usual: in appearance it resembled that of a child." (_Neue Zeitschrift fur Geburtskunde_, vol. xv. 1837.)

_Unequally contracted pelvis._ The unequally contracted pelvis (_pelvis inaequaliter justo minor_) may exist under a variety of forms; the most common is where the antero-posterior diameter is defective, or, in other words, where the distance between its anterior and posterior parietes is less than usual. In a slight degree, it is frequently met with among the poorer cla.s.ses, and arises from the patient having been compelled to carry heavy burdens in early childhood, or otherwise subjected to severe labour.

The practice of entrusting a girl of eight or ten years of age with the care of a heavy infant, which she carries about in her arms for many hours every day, is a fruitful source of this species of pelvic deformity; the young and plastic pelvis is unable to bear the additional pressure which is thrown upon the sacrum by the overloaded trunk, without having the just proportions of its growth materially influenced and perverted, especially at a period of life when the whole form of the pelvis is undergoing considerable changes. The constant pressure and counter-pressure to which the pelvis is subjected by the undue weight which is applied to the sacrum above, and supported by the resistance of the femora against the acetabula below, must necessarily tend at this age, even in an ordinary state of health, to impair its symmetry, more or less, and gradually to diminish the distance between its anterior and posterior parietes. Under no circ.u.mstances has this cause of pelvic deformity acted to such an extent as in the English manufactories, where young children are compelled to remain standing for twelve or more hours at the machines: the physical powers are unequal to the endurance of so much unceasing labour, the skeleton of the child soon suffers in its growth, and the pelvis almost certainly becomes contracted.

Similar effects may also be produced by undue pressure on the other parts of the pelvis. Thus the outlet may become much contracted by sitting many hours a day on a hard seat, as is frequently the case in schools. The tubera ischii are pressed together, the pubic arch is thereby contracted, and the sacrum becomes strongly curved forwards. Much riding on horseback at an early age is said to be injurious; and it is stated that the females of those American nations who are constantly on horseback bear but few children, and are frequently three or four days in severe labour.

_Rickets._ Similar effects, only in a much more aggravated form, are produced by rickets in early life; the pelvic bones having become soft from the loss of their earthy matter, gradually give way under the pressure of the superinc.u.mbent trunk, to the support of which they were unequal. In this way the sacrum is forced downwards and forwards towards the symphysis pubis, the acetabula are driven upwards and backwards, the pubic arch becomes distorted; and if the disease continues for a considerable period of time, the whole pelvis becomes so squeezed together as entirely to lose its original proportions.

The manner in which the distortion takes place varies exceedingly, and will be more or less influenced by the circ.u.mstances under which the child has been placed. The most constant change is the shortening of the antero-posterior diameter at the brim. In severe cases the base of the sacrum has, as it were, sunk down between the illia, so that its promontory occupies the cavity of the pelvis, the fourth, or third, or even the second, lumbar vertebrae occupying its former position. The gradual yielding of the bones seldom takes place with that degree of uniformity as to allow the sacrum to approach the symphysis pubis in a straight line: the more common result of rickets is, that the promontory is, at the same time, wrung more or less to one side.

"If the superior strait does not constantly present the same figure in deformed pelvis; if it is sometimes larger on one side than the other; if one of the acetabula is nearer to the sacrum, while the other approaches less; if the symphysis of the p.u.b.es is removed in many cases from a line which would divide the body into two equal parts, it is because the rickets has not equally affected all the bones of the pelvis, nor equally hurt all their junctions; and because the att.i.tude which the child takes in walking or sitting may change a little the direction of the compressing power, which I have just mentioned." (_Baudelocque_, translated by Heath, vol. i. p. 60.) Nor is it necessary that the degree with which the disease affects the different parts of the pelvis should vary in order to produce these inequalities of distortion, for there is no reason to suppose that the promontory of the sacrum would approach the symphysis pubis in a straight line, even where the softening of the bones was uniform throughout; the att.i.tude of the child, as above-mentioned, and the manner in which it supports itself, will have no inconsiderable influence in determining the direction in which the distortion takes place.

In those instances where the promontory is forced low down into the pelvic cavity, the sacrum becomes bent upon itself, the upper part of it forming a sharp curve backwards, while its lower portion together with the coccyx being confined by their attachments, and more or less compressed by sitting, are directed forwards. This is not seen where the projection of the promontory is but slight; the curve of the sacrum so far from being increased is rather lessened; the sacrum is straighter and flatter than usual, so that, although the brim of the pelvis is contracted, we not unfrequently find the outlet even larger than natural: in other cases, where the softening of the bones has gone to a considerable extent, the outlet is diminished, from the tubera ischii having been forced inwards.

The degree to which the promontory projects, of course, varies considerably. The distortion is occasionally so great as not even to leave an inch of antero-posterior diameter. This excessive deformity, however, is more frequently the result of mollities ossium coming on after p.u.b.erty, for we seldom find children live through this critical period where it has been the result of rickets. The brim of a deformed pelvis varies considerably in shape: "sometimes it has the form of a kidney, or that of the figure eight ([Symbol: infinity]); sometimes it is triangular or heart-shaped, the sides being curved inwards, from the acetabula having been pressed backwards or inwards, the ossa pubis are bent forwards and outwards, and form at their symphysis a sort of beak-like process, which is the apex of the heart: in this species of deformed pelvis, which is usually the result of mollities ossium, the outlet also is usually much distorted: this arises from the tubera ischii being forced nearer to each other, thus contracting the pubic arch." (Naegele's _Lehrbuch_, 2te Ausgabe, p. 247.)