Fig. 62.—Diagram showing method of ascertaining position of fetus by means of rectal examination. Examining finger palpates head through recto-vaginal septum.
Vaginal Examination. The information obtained by vaginal examination, before the cervix is dilated, is rather uncertain since the child’s presenting part must be palpated through the fornix. But after complete, or even partial dilatation, the exploring finger is able to feel the sagittal suture and one fontanelle, in a vertex presentation, and diagnose the position by discovering the direction of the suture and whether it is the anterior or posterior fontanelle that is felt. The anterior fontanelle, it will be remembered, is relatively large and four-sided, while the posterior is small and more nearly triangular in shape. In a face presentation, the features may be felt; in a breech the examining finger can palpate the buttocks and genital crease.
Because of the possible danger of introducing infective material into the birth canal, the tendency is to make fewer and fewer vaginal examinations, and then only after the most painstaking preparation which will be described presently. Needless to state, vaginal examinations are not within the province of the nurse.
Rectal Examinations. More and more frequently rectal examinations are being employed to obtain information about the child’s position, as the examining finger is able to feel the surface of the presenting part through the recto-vaginal septum, after the cervix is dilated, and there is no danger of infecting the birth canal while so doing. For this reason nurses are frequently taught to make rectal examinations, thereby increasing the value of their assistance to the doctor in watching the progress of labor. (Fig. [62].)
Auscultation of the fetal heart is valuable in confirming the diagnosis of presentation and position which has been made by palpation. In vertex and breech presentations the heartbeat is best heard through the baby’s back and in face presentations it is transmitted through the chest, which presents a convex surface in this case and fits into the curve of the uterine wall. In anterior vertex presentations the heart is heard a little to the side and below the umbilicus; in transverse, further to the side, and in posterior, well toward the back.
CHAPTER XI
SYMPTOMS, COURSE AND MECHANISM OF NORMAL LABOR
Labor may be defined as the process by means of which the product of conception is separated and expelled from the mother’s body. It ordinarily occurs about 280 days from the beginning of the last menstrual period. (See p. [93].)
The cause of labor is not known. Many theories have been advanced to explain why the uterine contractions, which have occurred painlessly throughout pregnancy, and without expulsive force, finally become painful at the end of the tenth month and so changed in character as to extrude the uterine contents; but as yet, none is wholly satisfactory nor generally accepted. Nor is it known why some labors are premature and some delayed.
The onset of labor is usually marked by the patient’s becoming conscious of the uterine contractions through dragging pains which may be felt first in the back and then in the lower part of the abdomen and the thighs. At first the pains are feeble and infrequent, but they gradually grow more severe and more frequent. Intestinal colic is sometimes mistaken for labor pains, but when the paroxysms are rhythmical and the uterus is felt, through the abdominal wall, to grow hard as the pain increases and soft as it subsides, there can be no doubt but that the patient is in labor. The first signs of labor may be a gush of amniotic fluid, caused by the rupture of the membranes, or of blood, but these are not typical.
For purposes of convenience, labor is usually described as consisting of three periods or stages. The first stage begins with the onset of labor and lasts until the cervix is completely dilated; the second stage begins with the complete dilatation of the cervix and lasts until the child is born; the third stage begins with the birth of the child and lasts until the placenta is expelled.