us first state the fact that, in transverse presentations, the fcetus never lies straight across the pelvis, but always obliquely, one extremity higher than the other, the lowest part being the head, the shoulder being generally in the plane of the superior strait. Hence the shape of the abdomen presents the peculiarity of seeming more distended in the transverse than in the vertical direction. On palpating the uterus, we find that the excavation is empty and that the fundus uteri may be depressed without enabling us to feel therein that resistant body Fhich we are accustomed to find there in longitudinal presentations: that the head is neither below nor above, any more than the pelvic extremity. On exploring the iliac fossm, we feel in one, at a greater or less distance from the margin of the excavation, a hard, round, prominent tumor which is often movable, especially in multipane, and gives the cephalic ballotte ment more or less distinctly. On moving the hands a little higher or lower on the opposite side, we encounter another voluminous part which is, however, less hard and less movable, near which small foetal parts are often found: this is the breech. If we depress the uterus in an oblique line from this superior prominence towards the head, we feel the resistant surface formed by the lateral plane of the fcetus, and thus the diagnosis of shoulder presentation is made. For instance, if the head is on the left side, it may be the right or the left shoulder; but if it be the latter, it is not the back of the fcetns which is felt, since this lies posteriorly, but the left lateral plane. The resistance offered by the lateral plane of the foetus will be very limited. If, on the other hand, it be the right shoulder, the back will be in front and entirely above the superior strait—the resistant surface will be much more extensive and more readily accessible. The same observation is true when the head is on the right side, and we have to deal with the right or left shoulder.
Hence we can thus diagnosticate both the presentation and the position; but this will only be feasible when the abdominal walls are supple, not thick, and the uterus is but slightly irritable, that is to say, not very liable to contract. At all events, if the diagnosis of the position cannot always be made, a great point gained is that the presentation has been clearly recognized, and that is always possible.
During Labor.
In the beginning, although more difficult, palpation is still the best method. The presentation can be recognized during the intervals be tween the contractions. Auscultation is always unsatisfactory; as to the touch, if the dilatation is somewhat advanced, it may discover a large bag of waters, but the presenting part remains almost inaccessible or at least affords no characteristic sensations. As soon as the membranes are rup tured, however, the diagnosis becomes possible.
Membranes Ruptured.—Owing to the evacuation of the liquor amnii, which is always abundant, the uterus diminishes in volume, applies itself more closely to the foetus, and hence, as Herrgott remarks, it changes its shape, and tends to reassume the vertical form. As a consequence, the
sensations obtained by palpation are somewhat different.
Palpation.—The head has reached nearer to the superior strait, without, however, leaving the iliac fossa, where it is recognized by its form and hardness, but it is no longer movable, cephalic ballottement fails. The pelvic extremity has approached the fundus uteri toward the median line, and the resistant plane uniting these two fcetal extremities has likewise become more nearly vertical, withal remaining more prominent on one side. Thus it seems as if the fetal trunk had become inclined toward the neck of the fcetus by approaching the head.
Auscultation has slightly changed, the horizontal decrease is no longer present, and the touch gives more definite sensations. The finger conies •upon a rounded part with a prominent osseous point, the acromion; on following this part we recognize successively the scapula, its spine, and the clavicle. But to recognize these different osseous prominences re quires great experience in the touch, and for our part there is a landmark which outweighs all the others, the axillary cavity formed by the arm on one side and the thoracic wall on the other. Moreover, this thoracic wall presents a series of eminences and depressions arranged parallel to each other like the bars of a grate, which Pajot terms the intercostal gridiron. The ribs being thus recognized, we are sure of having the lateral plane of the fcetus before us. Again, the axillary cavity bounded by the arm and the thoracic wall represents an angle, the point of which is necessarily directed toward the head. It is, therefore, a certain means of indicating the side occupied by the head in cases where it has not been discovered by palpation. The axilla is sometimes difficult to reach in dorso-anterior cases, when the finger must be carried far back, and we can thus always recognize the ribs. In such a case we sometimes encounter the vertebral column of the fcetus, which is marked by the row of projections formed by the spinous processes; on following them, we reach the scapula.
The head being recognized, and the anterior or posterior location of the back determined by the facility with which the ribs may be reached, the diagnosis is complete, that is to say, we know both the presentation and the position.
If we find: The head to the left, back anterior: it is the right shoulder.
46 66 64 posterior: " " left 66 right " anterior: 46 44 it if " posterior: " " right If we know the presenting shoulder and the position of the head, the diagnosis is likewise complete. • If we find: Right shoulder, back anterior, the head must be on the left. 44 " posterior, " " " " " right.
Left 46 " anterior, " " '. 4 16posterior, " " " " " left.
If, on the other hand, we know the shoulder and the situation of the head, the diagnosis is likewise complete.