The diagnosis of pregnancy is thus absolutely established. It remains for us to ascertain whether one or more foetuses are present, and to diag nosticate the presentation and the position. Let us remember that the head is a hard, rounded, and partially displaceable tumor, and that it is separated more or less perceptibly from the trunk by the furrow of the neck, according as the head is more or less flexed.
The nates also forms a bard, rounded, and moderately moveable tumor. But it is less hard, less round, less distinct, and larger than is the head, and, in the normal attitude of the foetus, it is always accompanied by smaller and more or less prominent and moveable parts, which are the feet.
Between these two parts there stretches a more or less extensive surface, the back of the foetus. And, since the foetus is curved upon itself, the back is always more plainly appreciable upon one side of the uterus than upon the other, and, on alternately depressing the two lateral walls of the abdomen, there will be felt on one side a feeling of fullness and resistance that is not felt upon the other side. .
Remembering that vertex presentations are the most common, and then those of the breech, the trunk and the face, we must first search for the head. This may be below the superior strait, at its level, or above it.
Placing the two hands flat upon the lower lateral walls of the abdomen, the hands being parallel to the iliac fossie, and the fingers reaching to the fold of the groin, the accoucheur slowly depresses the abdominal walls, and thus encloses between his hands the area of the superior strait. If the head is at its level, or just below it, it will be encountered somewhere near the median line, and may be seized between the hands. (Fig. 181.) If it is situated above the superior strait, it will be moveable; if a little engaged, it is moderately mobile. If it is entirely engaged, it is almost immoveable, and only the base of the head can be appreciated. Then, if we forcibly press our fingers into the furrow, we will reach a hard, round, and prominent tumor, which is the head. When, however, the head is above the superior strait, one hand alone, laid flatly just above the sym physis, will appreciate both its presence and its mobility.
When, however, the head is more or less deeply engaged, it is necessary to use both hands; and Pinard has drawn attention to the fact that, when the head is flexed, as it must necessarily be for engagement, there must be a depression of the occipital protuberance on the one side, and an elevation of the forehead upon the other. In consequence of this, one hand will
encounter more resistance than the other, and will penetrate less deeply. The most depressible side will correspond to the occiput, and the other to the forehead; and this will give us at once the direction of the back, which will always, of course, be upon the side opposite to the forehead. (See Fig. 182.) We cannot too strongly insist upon gentleness during the manipulation —the more gently the pressure is made, the more delicate and precise will be our sensations. Beginners often fail in their attempts at palpation simply because they contract their hands too forcibly. There should be absolutely no force used, since it causes the abdominal muscles and the uterus to contract, and renders palpation impassible. Palpation is only possible in the intervals of uterine contraction, and, when it occurs, we must stop, and begin slowly. The less we cause contractions, the easier will be palpation.
If we do not find the head about the superior strait, we must search for it elsewhere. Perhaps it is in one or other of the iliac fossEe, or it may be far away. In the first case, it is only necssiiry to slide the hands a little further to each side, to find the head. Its roundness, its re sistance and its mobility prevent our confounding it with the breech.
If, however, the head is not found either at the superior strait, or in the iliac fame, it is because the fcetus is not in its normal attitude, and we must then consider the possibility of the next most frequent presenta tion, that of the breech. It is therefore at the fundus that we must search for the head, although it rarely lies directly at the apex of the uterus.
Most often we find it at one of the lateral portions of the fundus, and in women at term, or near it, it must be searched for just under the false ribs. It will be felt then so distinctly that there is no chance of making a mistake. It can not only be moved with both hands, but one or two fingers will suffice to displace it. It is only necessary, with two fingers laid upon the head, to brusquely depress the abdominal wall, and the head will be felt to glide away quickly, and returning, strike the fingers with a very appreciable shock. This is what we call cephalic ballottement. (Fig. 183.) This sensation, once appreciated, can never be confounded with anything else.