The passive movements, or ballottement, are obtained by the manipulations of the examiner. The foetus swimming in the amniotic fluid is nearly of the same specific gravity, being a little heavier, it just swims in the fluid just touching the lower internal surface of the amnion at intervals. Consequently, if we sudden press upon the most dependent portion of the uterus, and then retain the finger steadily a that point, the foetus having been forced to rise in the fluid by the sudden pressure will soon return, and its weight will be felt as it again strikes upon the finger of the operator. The proper method of performing this operation by the vaginal tough, is to place the female either in the sitting or the erect posture; then with the finger upon the wall of the uterus, either in front or behind the cervix, curve the finger suddenly upward and forward, hold it there for a moment, when the foetus having been displace ad made to rise in the fluid, will rebound and impinge upon he finger which displaced upon the finger which no other condition of the female can possibly produce. The same experiment with a stone in the bladder might seem to simulate this; but the sharp, strong blow which would be given by a stone, would convey different impression from that of gentle, momentary touch of the foetus rebounding in the amniotic fluid.
The same ballottement sensation may also be obtained by placing the female upon her side, with the palmar surface of all the fingers applied to the most dependent part of the abdomen, forcibly flex them against he abdomen and hold from the upper side of the uterine cavity, where its movement may be felt against the other hand there applied, and settle down again upon the fingers with a certain gentle, subdued, unmistakable shock. the most favorable time for obtaining this sign of pregnancy, is at any time after the period of quickening, ad before the first of the ninth month; for then the child becomes too large to be easily displaced or to descend upon the finger. A six months and a half to the seventh month is the most satisfactory time.
Where, from the presence of the hymen, or the partial obliteration of the vagina, the examination per vaginam is inexpedient or impossible, it may be made through the rectum. But the unpleasantness of the operation, to the physician as well as to the female herself, would prevent resort the anal examination except in cases where no other method was available.
Auscultation as applied to pregnancy consists for he beating of the foetal heat. If the stethoscope the applied to the abdomen with care, at any time after the period of quickening, the heart of the foetus may be heard to beat nearly twice as fast as that of the mother, with a sound faint indeed and muffled, but still unmistakable. These pulsations generally become perceptible in the course of the fourth or fifth month and they range from one hundred and thirty sometimes slower without any assignable cause; apparently not in the least influenced by the changes in the pulse of the mother. The foetal pulsations will be most distinctly perceptible in that region of the abdomen which corresponds to the dorsal surface of the foetus.
They are more frequently heard over the left iliac fossa than over the right; less frequently on the median line above the symphysis pubis. There is always a point over which these sounds are most distinct; and they diminish intensity as we recede from this point. In their intensity these pulsations vary with the age of the patient, increasing in strength usually up to the full term. But the number of the pulsations is very much the same from the period of their being first distinguished up to the full term, except in some anomalous ass, When in the progress of labor the membranes are ruptured, the escape of he liquor amnii, by bringing the ear still nearer the foetus, renders the beating of the heart more distinct. The pulsations become less regular as the labor advances; and they are more slow and feeble during the contractions. Hence it becomes evident that the health of the child must always be more or less seriously compromised during difficult and protracted labors.
When the dorsal surface of the foetus is towards the abdomen of the mother, the pulsations are more distinctly heart; but after the sixth month they are be heard in any position of the foetus.
There are two distinct sounds observable in the beating of the foetal heat, corresponding to those of the adult heart, a first and a second is heard, the other may often be distinguished by examining in some different position.
I. As a sign of pregnancy the beating of the foetal hat is conclusive; since no other conditions can produce a similar sound.
Aneurisms of other abnormal pulsations of the mother must be synchronous with the pulse at the wrist, which is never the case with the pulsations of the foetal heart.
Double or twin pregnancies may be detected by hearing the pulsations of the foetal heart at two distinct parts of the abdomen; the sound becoming more and more distinct as you approach each part; while at the same time there is a perceptible want of harmony between the two sounds. In fact, there must be just as many foetuses in the mother’s womb, as we can thus trace foetal hearts, each beating independently of he mother’s pulse; and each growing more distinct as we approach the particularly part and growing more and more faint, as we recede from it. STill the apparent absence of the sounds of two hearts does not preclude the possibility of a twin pregnancy, since one foetus may be so directly behind the other as to mask its sounds.
The position of the foetus in the uterus can be determined to a limited extent only by auscultation. The pulsations heard most distinctly on the left of the median line, low down, just above the horizontal; ramus of he pubis, indicate the first position. When they are heard in the same situation on he right side, they indicate the second position. The sounds being heart on either side on a level with or even above the umbilicus, indicate a breech presentation.
A careful study of the sounds of the foetal heat both during he continuance of utero-gestation and at it is period in labor, enables us to determine the health of he child. Thus after he sixth month, when we have had sufficient evidence of the existence of pregnancy, the absence of the sound of the pulsations of the foetal heat ascertained by repeated examinations made at different times, will prove the death of the foetus. And during labor, if after the rupture of the membranes the pulsations of the foetal heat become irregular, more and more feeble, and more and more rapid, with irregularity of rhythm, absence of the second stroke, complete cessation of the beats during the pains, a nd slowness of their return after these have ceased, the life of the child is evidently threatened by further delay, and the labor should be terminated as promptly as possible. Still it should be remembered that just in proportion as from auscultation we have reason to conclude that the child is not longer living or viable, we should give out principal attention to the mother and given our conduct by indications derived from her condition. For in many cases of protracted labor in which the pulsations can still be distinguished at the moment of birth, the child has already suffered so much that respiration cannot be established. while the positive evidence of the death of the foetus in utero which may be afforded by auscultation leaves us at liberty to resort to craniotomy, under circumstances in which it might not be justifiable if the child were still living.
II. The bellows murmur, bruit de souffle, although capable o of being distinguished before any of the other intra-uterine sounds, before the beating of the foetal heart can be heard, is here mentioned in the second place, since it possesses little or no diagnostic value. This sound may generally be heart as soon s the uterus has risen out of the pelvic cavity; that is a little earlier than the sound of the foetal heart can be made out. From the supposition that it was produced in the utero-placental circulation it has been called the placental murmur. From being supposed by other to be produced by pressure of the posterior plane of the abdomen it has been termed the abdominal souffle. From being supposed to originate in the enlarged vessels which ramify in the walls of the uterus, it has received from others the name of uterine souffle. The fact that this sound has been distinctly heart for a short time after delivery is conclusive against the placental theory. The double fact that this sound is heard as distinctly in the same position, when the pressure made upon the anterior of the uterus directly towards e spine, proves no less conclusively that it is not caused by obstruction of or pressure upon the iliacs and the aorta. There remains only the hypothesis of the uterine sinuses; and here the following circumstances may be considered as decisive of the question the bruit is heard in the earlier part of the second moiety of utero gestation, nearer the pubes, and it gradually ascends with the upward advance of the uterus it is most distinctly heart in that portion of the uterus where its vessels are largest, and finally i may be heard through an instrument (the metroscope of M. Nauche) applied to the cervix uteri, when it cannot be distinguished by the ordinary abdominal examination.
