Ballottement consists in the detection in the uterus of a movable solid body surrounded by fluid. In a standing position, the fœtus rests in the lower part of the uterus, just above the cervix. The woman stands with one foot on a low stool, and two fingers of one hand are pushed into the vagina until they touch the cervix, the other hand is placed on the fundus. A smart upward blow by the internal hand is transmitted to the fœtus, and it can be felt to leave the cervix, strike lightly the tissues underneath the external hand, and return to the cervix. It is simulated by so few things, and so rarely, that in practice it must be regarded as a positive sign.
During the second half, the subjective symptoms are of minor importance since unmistakable evidence is furnished by the physical signs. The symptoms of this period are mostly discomforts. Increased intraabdominal pressure brings on edema of the feet, cramps in the legs, varicose veins of the legs and vulva, dyspnœa, and palpitations.
Twenty-sixth Week.—About the twenty-sixth week, or, at the end of the sixth calendar month, the hypertrophy of the breasts, the presence of secretion, and the marked pigmentation are unmistakable. The abdominal protrusion is now clearly visible, and the fundus will be found at the level of the upper border of the umbilicus.
Spontaneous fœtal movements appear and may be felt by the palpating hand.
Auscultation reveals the uterine souffle and the fœtal heart sounds. The heart sounds and the fœtal movements, when obtained by the observer, are positive signs.
Uterine souffle is a soft, blowing murmur, synchronous with the mother’s pulse. It is best heard at the lower parts of the lateral borders of the uterus. It is due to the passage of blood through the greatly dilated uterine arteries. It may be heard also in cases of fibroid tumors of the uterus.
Fig. 27.—Abdominal enlargement at third, sixth, ninth, and tenth months of pregnancy. (Williams.)
Fig. 28.—Height of the uterus at various months of pregnancy. (Bumm.)