APPLICATIONS OF THE FORCEPS IN FACE PRESENTATIONS.
The face, even as the vertex, may lie at the level of the inferior strait, in the cavity, at the superior strait, above it. Usually, in each of these instances, the head is diagonal or transverse. The antoro-posterior di ameter of the pelvis is too small for the occipito-mental, and therefore a mento-sacral position, properly so-called, does not exist, and the same is true of the mento-pubic. We may have a mento-sub-pubic position—that is to say, rotation has been affected, and the chin is under the pubes. Direct application of the forceps is exceptional in face presentations, and it is usually the oblique which is practised.
The general and special rules are the same as for the vertex; two con ditions, however, lead all the others: 1. The instrument must be applied to the sides of the face, to avoid wounding it anteriorly, or the neck. Occasionally, as we will see, we have no choice in this matter.
2. The absolute necessity of making the face rotate, in order to bring the chin under the symphysis. Indeed this rotation may alone allow us to terminate labor without mutilating the fetus.
In these instances, more even than iu case of the vertex, the hand must be introduced deeply to protect the maternal and the foetal parts. The chin must always be brought under the symphysis, because transforma tion into the vertex is only possible when the position of the face is frontal, or when it is above the superior strait. In the first we must wait, for this transformation may occur spontaneously; in the second, it is version to which we should resort, and not to the forceps.
We must never forget that in face presentations labor is always pro longed, and that, therefore, we must have plenty of patience.
Pinard advocates placing the blades nearer to the chin than to the brow, ready to remove them, and re-apply as soon as the chin has been brought down. This is good advice, but although easy of performance on the manikin, it is far from being so on the living female. The great difficulty in face presentations is to apply the forceps to the sides of the face, and while this is possible when the head is in the cavity, it is not so when the face is still elevated. Usually we must be content with grasping
the head obliquely, from one frontal protuberance to the maxillary angle.
We must remember, further, that transverse presentations of the face are relatively frequent compared to the others, and that in such cases we are obliged to grasp the head obliquely as in transverse presentations of the vertex, the very situation of the face preventing its being seized laterally.
All the authorities agree in regard to the difficulties of application and of delivery in face presentations. The chin must not only be brought down, but it must, as well, be brought forward; the face must not only be brought down, but it must, in particular, be rotated in order to bring the chin under the symphysis. Often all our efforts fail and we are obliged to mutilate the fcetus. The greater the reason for this, if, as not infre quently happens, with the face presentation there is prolapse of a fcutal Part.
A. The Face is in the Cavity, having passed through the superior Strait.
1. Menlo-pubic, or, better, mento-sub-pubic. —The forceps is applied directly, the chin being under the symphysis and the forehead in the pel vic curve; that is to say, the fronto-mental diameter lies in the antero posterior of the pelvis. The bi-malar diameter is in the transverse of the pelvis. The left blade is inserted first to the left on the right side of the face, the right blade second to the right on the left side of the face, the lesser curve pointing towards the symphysis. It will be sufficient to gently lift up the forceps, and the head will appear, in succession, by its sub-mento-frontal, sub-mento-bregmatic, sub-mento-occipital diameters. (Fig. 103.) 2. purely theoretical, and does not exist in practice, the chin being always to the right or to the left, towards one of the sacro-iliac synchondroses, and the position thus really is (right or left).