able by the forces of nature. It is far more difficult, however, to classify precisely other positions. First of all, face and footling presentations cannot be considered normal, because the fœtus has lost its normal attitude. And this is the less advisable because footling presentations, if left solely to the forces of nature, are very unfavorable for the child, and face presentations are not only tedious both to mother and child, but delivery is slow, and this alone clouds the prognosis. Breech presentations proper may, indeed, be placed in a mid position between normal and abnormal. For, on the one hand, they are relatively frequent (about 3 per cent.), the mechanical passage through the maternal parts is here rather more easy, and certainly not more difficult than in head presentations, and the prognosis is here also at least as favorable for the mother as in the latter. On the other hand, the prognosis for the child is far more unfavorable. According to Ch. Bell (Monthly Journ. of Med. Sc.,' September, 1853, p. 225), of 2367 breech presentations, 519 children were stillborn, i. e. 22 per cent., and not infrequently they require in the last stage the assistance of art for the delivery of the head, so that they can certainly not be called quite normal labours. A normal parturition proper is exclusively represented by a head presentation, and even in that deviations in the position and attitude of the head occur which cannot be considered normal.

If from this place, which is devoted to the physiology of parturition, we exclude the transverse positions and consider all the longitudinal, it is not because all the latter are normal, as has been explained above, but it is done from a practical point of view. Apart from the diagnosis, the transverse positions are excluded, because in them there cannot usually be the question of a mechanism of parturition proper. Therefore, to obtain uniformity in the description of the way in which the foetus is expelled through the pelvis, all the other positions will be considered together.

In head and breech presentations the position of the foetal parts is of great importance for the consideration of the mechanism of parturition. A distinction is therefore made according to whether the back of the child is placed opposite the left or the right side of the uterus. The former, twice as frequent, is called the first, the latter the second head or breech position. By a vaginal examination the position of the child can be made out from the presenting part. The small fontanelle, the forehead in face presentations, or the sacrum correspond to the side towards which the back of the child is situated. It is of importance also to ascertain whether the back of the child accurately lies towards the side, or whether it is directed more forwards or backwards. Most frequently, but by no means exclusively, the back lies more forwards in the first and more backwards in the second head presentation. This observation can easily be explained by what has been stated with regard to the causes of the position and presentation of the fœtus. The circumstance also that the first head presentation is twice as frequent as the second cannot appear strange if we consider that out of twenty-four hours the woman passes sixteen in the erect and eight in the recumbent posture.

The most frequent of all presentations is that of the head; it is seen in 95 per cent. of all cases of labour (once in 1·05 cases). Face

presentations occur in 0.6 per cent. (one in 166 cases); pelvic presentations in 311 per cent. (once in 321 cases); and transverse positions in 0.56 per cent. (once in 178 cases).

The frequency of the first head presentation to the second is as 2.26 to 1 (Hecker).

That of the first face presentation to the second is as 14 to 1 (Winkel).

The first pelvic presentation is met with three times as often as the second. Breech presentations are twice as frequent as footling.

Knee presentations are exceedingly rare; 1 in 185 breech presen tations.

CHAPTER V

DIAGNOSIS OF THE FETAL POSITIONS

It is highly important to know, as early as possible after labour has set in, the position of the fœtus. If the presenting part is low down, and the membranes are ruptured, the position can usually be recognised without difficulty by an internal examination. But if the membranes are very tense, and the foetal parts too high for the examining finger, the position must be determined from an external examination. By it excellent results are obtained if the uterus is flaccid in the intervals of the pains. For a less practised observer, under not too unfavorable conditions, the foetal position is less liable to be mistaken from an external examination than from an internal made alone. The former ought never to be omitted, because it gives an excellent control over the results obtained by the internal examination.

A. THE EXTERNAL EXAMINATION

The most important points for the diagnosis of the fœtal position by an external examination will be obtained by palpation. First of all we must ascertain if the position be longitudinal. For that purpose the accoucheur stands at the side of the bed, and places his hands upon the abdomen of the pregnant woman, so that the tips of the fingers are directed to the symphysis, the wrist to the navel of the woman. By short tapping movements it can be ascertained if a large part lies movably above the pelvic inlet, for if that is the case a distinct sensation of ballottement is obtained. If that part is slightly deviated to one side, one of the two hands feels it still more easily. If that large part is fixed in the pelvic inlet, it can also be easily felt through the lower segment of the uterus. It is, however, more difficult to feel if it has entered the small pelvis to a great extent or entirely. Nothing more can be made out then but that the perceptible tumour is continued into the small pelvis, since the hand cannot pass deeply between the symphysis and the lower segment of the uterus. It is evident that in such cases the internal examination will afford very material assistance. But to obtain information as to the position of the other large part it is best to sit on the edge of the bed, and to place both hands in such a way upon the abdomen of the parturient woman that the tips of the fingers are directed towards the sternum, and now to endeavour by short tappings to produce ballottement also in

the fundus uteri. In that way the large part lying in the fundus can easily be made out.

If the position be vertical, we have to determine whether the head or the breech presents. The chief distinction between these two is that the head feels harder, and therefore ballottement is more distinct and more easily produced. Again, the head is larger and less convex. Then the discovery of the limbs, which are closely attached to the breech, may aid in the diagnosis, for in the head presentation there is first the interval of the neck, and then only the attachment of smaller parts. Fassbender draws attention to the fact that frequently the parchment-like crepitation of the cranial bones may be felt under favorable conditions through the abdominal walls, and thus the head can be distinguished with certainty from the breech. Sometimes, especially in a small fœtus, the head feels remarkably small and pointed, so that it could be easily mistaken for some other foetal part. From it, however, it is distinguished by ballottement, which is never obtained with small parts.

The question whether the presenting part is in the first or second position is usually not difficult to decide. First of all the large part situated above must be made out by palpation; a hasty decision must not be made as to its absolute position in the abdomen; careful examination must show on which side of the large part the small ones can be felt. For it is found in great lateral deviation of the uterus that a large part can be decidedly felt on one side, say the right, of the abdomen, so that the assumption would be that the position is the second. Yet by careful palpation no other foetal parts can be felt on the left, whilst they can be distinguished on the right of the large part; the position, therefore, is the first. It may also be difficult to feel the small parts if the back is almost entirely situated in front, and in such cases, if the head is not yet fixed in the pelvis, the back may not infrequently be brought now to the left, and at another time to the right.

Auscultation materially assists in determining whether the position is the first or the second. However, it is not sufficient to hear the sounds of the foetal heart, but the place must be found where the sounds are most distinctly heard. In the first position the heart sounds are heard in the left lower region of the abdomen, somewhat to the outer side, and rarely only near the middle line. In the second position the sounds are very distinctly heard (corresponding to the situation of the heart in the left thoracic cavity) usually to the right, close to the linea alba, rarely far externally, but sometimes a little to the left of the linea alba. Considerable deviation of the uterus to the right or left may easily give rise to mistakes if the linea alba is taken as a limiting line, and not the middle line of the uterus. As an aid to diagnosis between head and breech presentations, auscultation is only to be used with great caution. Frequently, indeed, the sounds of the foetal heart are heard very high up in the region of the umbilicus in breech presentations, but this is by no means constant, and occurs also in head presentations.

On the other hand, auscultation is highly useful to distinguish between face and head presentations, for in the former the thorax

lies so much in that half of the uterus which does not correspond to the back that there the heart sounds are best heard. Thus, even in the first face presentation the breech is felt high up to the left, to the right of it are the small parts, and the heart's sounds are heard to the right of the linea alba. If, moreover, the occiput is felt projecting over the left pubic ramus, a face presentation is certain.

It is most difficult of all to decide from an external examination whether the breech or the feet present. The latter may be diagnosed if the breech is somewhat deviated to the side where the back lies, i. e. to the left in the first position.

Transverse positions are recognised by a large movable part in each side of the uterus whilst the fundus is empty, and the examining hand can more or less easily pass between the symphysis and the lower uterine segment. The distinction between head and breech is often easy, but sometimes it is, on the contrary, very difficult. The heart's sounds are usually heard more to the side in which the head lies. If through the anterior abdominal walls small parts are distinctly felt, the back lies behind and somewhat below.

B.-THE INTERNAL EXAMINATION

By the internal examination, especially when the presenting part is sufficiently low down, and when the membranes are flaccid or already ruptured, a practised observer is able to obtain precise information, not only as to the presentation, but also as to the position of the child. But to a less practised one this internal examination gives rise to a variety of mistakes, and it is therefore advisable always to control the results of an internal by an external examination.

The head is known to present from the large round body of uniform bony hardness, which easily produces ballottement if it is still high up and movable. If fixed it is usually easy to feel on it the sutures, and at least one fontanelle. For further information the examining finger must pass along the head towards the maternal sacrum. In this way the finger comes to a suture, which, in the great majority of instances, is the sagittal suture. It must be followed to both sides as far as possible until a place is reached where several sutures meet. The shape of the two fontanelles serves to distinguish them from one another. Yet they can be mistaken, especially if the bones are so tightly compressed that the space of the large fontanelle entirely disappears; the small fontanelle also may be strikingly like a deficiency in the bone if the apex of the occipital bone is pushed under the parietal bones. Exceptionally, a fissure with diverging margins is found at the superior angle of the occipital bone, or a Wormian bone is inserted, and then the shape of the small fontanelle is just like that of the larger. Not infrequently a rhomboidal opening is met with along the sagittal suture, about one centimètre in front of the small fontanelle, which may also lead to mistakes.

The small fontanelle is recognised by three sutures proceeding