The most important changes in the tubes and ovaries is in their position because of their being carried up from the pelvis by the enlarging uterus into the abdominal cavity. Although they increase in vascularity, ovulation is ordinarily suspended during pregnancy.
The abdomen as a whole changes in contour as it steadily enlarges, and the skin and underlying muscles are somewhat affected as a result. The tension upon the skin is so great that it may rupture the underlying elastic layers which later atrophy and thus produce the familiar striæ of pregnancy, known variously as the striæ gravidarium and the linea albicantes. Fresh striæ are pale pink or bluish in color, but after delivery they take on the silvery, glistening appearance of scar tissue, which they really are.
In a woman who has borne children, therefore, we find both new and old striæ; those resulting from former pregnancies being silvery and shining, while the fresh tears are pink or blue. Striæ may be found also on the breasts, hips and upper part of the thighs, and as they are of purely mechanical origin, are not necessarily associated with pregnancy alone. They may result from a stretching of the skin by ascites, a marked increase in fat or an abdominal tumor.
The same distension that causes striæ sometimes causes a separation of the recti muscles. This separation, known as diastasis, is sometimes slight but frequently very marked, the space between the muscles being easily felt through the thinned abdominal wall.
The umbilicus is deeply indented during about the first three months of pregnancy. But during the fourth, fifth and sixth months the pit grows steadily shallower, and by the seventh month it is level with the surface. After this it may protrude, in which state it is described as a “pouting umbilicus.”
The increased pigmentation at the umbilicus and in the median line is scarcely to be classified among the abdominal changes, as the skin elsewhere presents the same discolored appearance. The degree of pigmentation varies with the complexion of the individual, as blondes may be but slightly tinted while the discolored areas on a brunette may be dark brown, sometimes almost black.
The changes in the breasts during pregnancy were practically all included in the enumerated signs and symptoms of pregnancy. They increase in size and firmness and become nodular; the nipple is more prominent and together with the surrounding areolæ, grows much darker; the glands of Montgomery are enlarged; the superficial veins grow more prominent, and after the third month a thin, yellowish fluid can be expressed from the nipples. This fluid, called colostrum, consists largely of fat, epithelial cells and colostrum corpuscles and differs from milk, in its yellowish color, and in the fact that it coagulates like the white of an egg when boiled. The previously quiescent mammary glands develop very early in pregnancy an ability to select from the blood stream the necessary materials to produce a secretion. Colostrum is the product of their activity until about the third day after delivery, when milk appears.
Changes in the cardio-vascular system are among those which are not altogether understood, and it is still a moot question as to whether or not there is an actual increase in the amount of maternal blood during pregnancy. But results of the most recent investigations suggest that there is a definite increase in both the cells and the plasma. This increased amount circulating through the heart subjects it to a certain amount of strain, with the result that the organ is slightly hypertrophied and the pulse pressure is higher.
The respiratory organs do not show any marked alterations. The upward pressure of the enlarging uterus gradually shortens the height of the thoracic cavity, but if it grows sufficiently wide in compensation, there is no decrease in the capacity of the lungs. If this does not occur, the patient may suffer from shortness of breath. The larynx is sometimes reddened and edematous, a fact which explains the damaging effects which child-bearing may have upon the voice of singers.
Changes in the digestive tract during pregnancy are the morning sickness already described, and constipation. The latter is suffered by at least one half of all pregnant women, and is due chiefly to pressure of the uterus on the intestines, though impaired tone of the stretched abdominal muscles may be a factor. This condition is most troublesome during the latter part of pregnancy. There also may be gastric indigestion causing acidity, flatulence and heartburn, and intestinal indigestion giving rise to diarrhea and cramp-like pains. The appetite may be very capricious during the early weeks, and become almost ravenous later on.