False pains may appear, especially in multiparas, from two to four weeks before labor. In some of these cases the pains may be due to gas or indigestion and respond to hot applications and enemas, or there may be definite uterine contractions, as shown by the hardness of that organ during a pain, but the phenomena are irregular and therefore not typical of labor pains.
Usually they pass off in a few hours, but if the patient is nervous, the doctor or nurse may be called needlessly. The patient, therefore, should be instructed to have the pains timed by the watch for half an hour or an hour. If they are regular during this period, the physician should be notified. Upon his arrival, an internal examination will reveal the true character of the disturbance by the condition of the cervix and os.
The show is a discharge of thick, white mucus, slightly stained with blood. This is the mucus plug which occludes the cervix during pregnancy and when the os begins to dilate, the mass is released and passes out. Labor usually comes on vigorously within twelve hours.
The membranes may rupture before labor begins and much fluid escape. The advantage of the dilating bag of water and lubricating qualities of the liquor amnii are thus lost. Such a labor is called a “dry birth” and is frequently slow, exhausting, and extremely painful.
The pains are the subjective manifestations of the powers of labor. The forces concerned are uterine and abdominal muscles, principally assisted by those of the back, legs, and arms. Their constricting action on the nerve fibers in the walls of the uterus is the cause of the pains in the first stage. The onset may be violent and go on to a quick delivery, but generally the inception is more insidious.
The irregular, painless contractions, (of Braxton Hicks) that were mentioned on an earlier page, gradually at term change their character and become regular and painful.
At first they may be slight and vague, lasting only half a minute and separated by intervals of ten or fifteen minutes and scarcely attract the patient’s attention. They are felt chiefly in the abdomen.
More or less rapidly they increase in frequency, severity and duration. They last from a minute to a minute and a half and come every three minutes. The whole uterus hardens and its outline is clearly defined during the contraction; it relaxes and becomes soft in the interval. The woman is now in labor. The pains become grinding and the patient feels that she is not accomplishing anything, yet under the influence of these contractions the cervix is effaced and the os is dilated.
The Course of Labor.—Labor is divided for convenience into three stages as follows:
The first stage, from the beginning of pains until the complete dilatation of the os.