Labor, or parturition, completes the grand function, of reproduction; and by it either spontaneously, or by nature, by art, or by both conjoined, the new being is ushered forth to assume an independent existence with all other isolated existences.
Labor is considered natural or spontaneous, when it is accomplished by the unaided powers of nature; and artificial or unnatural, when manual assistance is found necessary. Labor is also considered timely or at term, when it occurs at about the expiration of the ninth month of utero gestation; premature or untimely, when it occurs at any time between the first of the seventh month and full time. Provoked labor is one which has been produced by some mechanical cause, either accidental or designed. A retarded labor is one that is delayed beyond nine and a half or ten months of gestation.
PREMATURE LABOR. Premature labor may result from a great variety of causes, accidents of any kind, disease incidental to the pregnant condition, or other as, as described in the chapter on Abortion. For the precautions and remedies to be employed, in case of threatened premature labor see also the preceding chapter on Abortion. It may be stated here however that all women should use extra precautions at about the seventh month of gestation. In premature labors the first stage is usually longer in proportion than the second, which latter is generally longer than a labor at full term. Also vertex presentations are far less frequent, and cross, breech, or irregular presentations are much more frequent. Another proof that the foetus takes the most natural presentation and position from an inherent disposition on the part of the mother to secure this result. There is great danger from hemorrhage in premature labors; consequently more need of quite rest form the first symptoms, and ever after till all danger is past: and so much the more need of carefully selecting the proper remedy.
RETARDED LABORS. The ordinary time for gestation is two hundred and seventy five-days; but as there are exceptions to all other rules, we might naturally conclude they would be found here also. ( T smith’ Obstetrics, p. 212). Accordingly investigation has been made, and out of forty-three instances of conception after as single coitus, collected by Dr. Reid, all of them resting upon testimony as credible as can be abstained in such case, of which the average duration of gestation was two hundred and seventy five days, three were delivered at the 280th day; two on the 283d day; one each, on the 294th and 286th days; two on thee 287th; one on the 291st; two on the 393d, and one each, on the 296th and 300th days. According to the french law, every child born after the one hundred and eightieth or before the three hundredth day of marriage is considered legitimate.( Cazeaux, p. 378).
NATURAL LABOR AT TERM. In the study of this subject, two orders of facts must be separately considered, the one regarding the physiology of labor on the part of the mother; the other consisting of the movements which the child must execute in order to promote its passage from the uterus through the organs of generation. The former is to be regarded as purely functional; the other as simply mechanical. Let us first consider the subject functionally, with reference to the vital action of the mother.
CAUSES OF LABOR. These causes of labor have been divided in to the efficient and the determining causes. The efficient causes are unquestionably the vital energies of the mother, brought to bear in every possible manner upon the child for its expulsion, and at the same time to open up the way as much as possible for its exit. The uterus itself, acting involuntarily, is the chief agent in the expulsion, aided more or less by the voluntary efforts of the mother; while at the same time an involuntary dilatation is effected of the os uteri, vagina and external organs. All these processes on the part of the mother are purely functional and involuntary, as much so as are the processes of conception, gestation, digestion, nutrition, etc. The efficient cause of the labor is in only the last part of the grand function of reproduction. How important then that most sacred function should not be disturbed by any influences whatever; but should be sedulously watched ovary a careful and skilful Homoeopathic physician, ready to administer the proper remedy for whatever deviation from the normal condition may occur. How different when the blood is poisoned and the sense stupefied by anesthetics; how impossible then for the mother to give the alarm, o for nature to respond and furnish the symptomatic sings of danger till it is too late!
The determining cause may be any influence by which the efficient cause is set in motion. At the full term, when thee woman should be delivered, the determining cause becomes spontaneous; the grand function of reproduction is about to be completed; and here as in all other vital processes there is not delay; the work constantly advances till parturition terminates and completes to the very last the great process of reproduction. At the full term, or even a few days before, various kind of accidents, diseases or mechanical means may become the determining cause, by arousing the efficient cause in the contractive and Expulsive action of the uterus; but this function of parturition will not be so safely or so easily accomplished when thus excited by external influences, as when it begins in perfectly natural and spontaneous manner.
THE PHYSIOLOGY OF LABOR. The phenomena of labor may be arranged in three distinct groups or successive stages. The first including the whole period form the commencement of the labor to the complete dilatation of the os uteri; the second extends from the dilation of the os uteri to the expulsion of the child; the third terminates with the final delivery of the placenta.
I. The first stage. The approaching termination of gestation is indicated usually by various symptoms called precursory signs of labor. About the last two weeks a change become perceptible in the form of the abdomen. Its sides become more projecting as the uterine tumor sinks form the region of the stomach and epigastrium; so that respiration become easier and food can be taken with less discomfort. And in many respects the woman feels lighter, better and easier. This change results form the cavity of the body and of the neck of the uterus being blended into one by the softening and giving way of the os internum uteri. The calls to urinate now become rather more frequent; the sleep is more broken by restlessness, and waling becomes more difficult. The women becomes more clumsy; and a little later, glairy discharges take place from the vagina, which simply show an increased action of the muciparous glands preparatory to the final act of parturition.
Finally the first stage is ushered in by painless contractions, which after a while become somewhat painful, and finally more and so. The mucous discharge often becomes more or less tinged with blood; the os uteri dilates more and more with every orderly contraction; the parts become bathed with moisture, and the upper portion of the vagina gradually dilates simultaneously with the os uteri. During this stage the female may walk about, sit, or lie down, as she finds most comfortable. Her respirations is usually continuous with every pain; there may be a sort of shivering like respiration; at times violent shiverings and shudderings seize upon her, although she does not feel cold, and she wonders why it is she shakes so. This shivering is one of the phenomena most usually witnessed during an orderly first stage of labor.
II. The Second Stage. This is at once marked by a change in the respiration; instead of the shivering-like respiration continuing during every pain, the breath is held in as when making an expulsive effort at stool.
Up to this time the only muscles concerned in the contractions have been those of the uterus itself. ITs fibres have been employed in assisting in the dilatation of the os uteri; and when this is sufficiently accomplished, all the muscles of the trunk become engaged in the last act of reproduction. Hence the involuntary suppression of the respiration during the pain, and the expulsive efforts of every muscle in the trunk, including the diaphragm, to being the new human being to light.
As one contraction or pain succeeds another, the liquor amnii forces the membranes to yield, and they bulge into the vagina, forming a sack, or what is called the bag of waters, which finally ruptures, when the child is driven onwards with more rapidity than ever, the floor of the pelvis gradually distends before the presenting part, till at length the vulvae become distended more and more with every pain; until finally the head bursts through, followed presently by the remainder of the body, and the work of reproduction is accomplished.
III. The Third Stage. Before proceeding to the more extended consideration of the second or most important stage of labor, it will be proper to notice in brief the phenomena of the third. These consist in resumption of the Expulsive pains, usually after an interval of from fifteen to twenty or thirty minutes, or even more, after the birth of the child. By these contractions, the placental mass is gradually detached from its adhesion to the uterine wall; and expelled from the uterus into the vagina, or completely without the body. The subsequent pains, after-pains, serve the important purpose of completing the contraction of the uterus, and, by thus covering up the open mouths of the blood- vessels, (uterine sinuses,) of arresting the hemorrhage which otherwise would soon prove fatal.
A pain in labor signifies the contraction of such muscular fibres as are concerned in giving to the child; and the sensation of pain produced in such contractions results from pressure upon the nerves distributed in the tissues, especially of the uterus itself, thus contracting. The sensation of the is felt in the back, abdomen and elsewhere, by virtue of reflex action, but which the seat of the pain is located at the central origin of the nerves themselves, rather than at their peripheral terminations. During the entire course of the parturition, the child takes no part in its delivery, it is entirely submissive, as it has been during its entire stay in the uterine cavity; it is entirely neutral and passive, and is expelled entirely by the last act of reproduction on the part of the mother.
The more active the muciparous glands in this vital act, the more easily is the child brought forth; the abundant glairy discharges rendering the labor a moist one and comparatively easy; where little or none of this mucus is secreted the labor is called dry, and is consequently more painful and tardy.
The bag of waters, known as such, is simply the amnion and chorion distended in advance of the presenting part of the child, by the bulging of the liquor amnii in consequence of the pain.
The duration of labor is exceedingly variable, even when no obstacle seems to oppose the delivery, from one hour or to a week; and between these two extremes there is every intermediate grade. In general, labor is longer in primiparae than in those who have had many children, or are nearer the climacteric period of life. As a general rule, the average length of time may be set down at from six to twelve hours. The duration of the labor is expected to be announced as soon as an examination is made per vaginam. But much caution should be used in this matter, for it is discouraging to the patient to overrun the specified time. After the first stage is passed, the second will be two or three times shorter, other things being equal, the diameter of the straits all being normal and there being no undue rigidity of the soft parts. In other cases, the time will very, according to the changes conditions. It is, after all, utterly impossible to predict the time of delivery with certainty.
The Effect of Labor upon the Mother and Child. On the part of the mother there is often much despondency at the commencement of labor; and during the first stage there is apt to be more or less distress of body and mind, a feeling of despair, as if she could not endure to the end. But, as soon as the second stage sets in, the patient nearly always raises her spirits, she becomes more hopeful and bears her pains, and voluntarily exerts herself, with confidence that she will be delivered all right. She often perspires profusely and becomes much exhausted during labor. The whole process of parturition is certainly very shocking to the nervous system, and there is danger of great prostration during delivery, similar in effect to the produced in persons sustaining a severe mechanical injury, even a complete collapse may sometimes occur. Great care is needed, immediately after the completion of this great event, that the patient get quite sleep as soon as possible. She should no be allowed to talk, and much less should the accoucheur try to have a little pleasant conversation with her after the labor is over. Such a course cannot to too severely censured, since it may be attended with fatal consequences. A little sleep makes all safe.
On the part of the child, the effect of the labor varies with its severity and its duration. And the shock of the compression of the uterine contractions is more severely felt upon male than upon female children, as before stated; in many cases, the sad effects are immediate; in others, more remote, and proportionally more injurious.
The mechanical phenomena of labor have relation strictly to thee child. It is very evident, from the knowledge we possess of the form and mechanism of the pelvis and also of the child, that there must be a mechanical adaptation of the latter to the former, in order that it can be born; and that, in order to secure this result, there must be certain presentations and positions at the superior strait.
Almost any part of the child may present at the superior strait, making almost an infinite variety of presentations; but, for all practical purpose, it will be sufficient to describe only five. For, when the accoucheur recognizes either of these, he will be able to determine what, if any, mechanical means may be needed to produce relief.
Each of the five presentations may have one of six positions, as for instance, in the vertex presentation, the occiput must lead the way in labor, since it is one end of the head. Then we describe the occiput as being in the left iliac region, anterior, transverse, or posterior; or the right iliac, anterior, transverse, or posterior. That is to say, the position is left occipito-iliac, anterior, transverse, or posterior, according as the occiput is in the half of the pelvis and at the ileo- pectineal eminence, exactly transverse across the pubis, or at the sacro-iliac symphysis. The same terms would be applicable in all respects, if the occiput were in the right half of the pubis, and at those various points respectively.
In facial presentations the chin would lead, then of course the position would be styled, right mento-iliac, anterior, transverse, or posterior, if in the right half or the left mento-iliac, anterior, transverse or posterior, if in the left.
In presentations of the breech, the sacrum is the point of departure. and is called according to circumstances, the right or the left sacro iliac, anterior transverse or posterior, position.
In presentations of the the right lateral plane, the head must be either in the right or left half of the pubis, and the position must be called the right cephalo-iliac, anterior, transverse or posterior, according to circumstances; and similarly in the left half of the pubis. In presentations of the left lateral plane, the same terms, according to circumstances, must express the position with sufficient accuracy for practical purposes. Each of these presentations will now be particularly explained.
The Vertex Presentations. This occurs very much more frequently than all the others put together; for instance, of twenty-two thousand five hundred nd thirty-seven carefully observed cases, only eight hundred and fourteen were found to be of any other presentation. And of the vertex presentation the very much larger proportion of cases is found to be in the left occipito0iliac anterior position. This position, which occurs the most frequently, is found to be the easiest and most natural of all.
The diagnosis of the vertex presentation is made out by feeling a large, round, hard, smooth tumor, while examining per vaginam, either at the superior strait, or descending into the cavity of the pelvis. The stethoscope will also reveal with much certainty the presentation of the vertex, by the beat of the foetal heart being heard low down in the abdomen. The vertex presentation being made out, it remains to define the position by means of the position of the fontanelles and sutures.
By carrying the finger a little backward and upward on the head the sagittal suture will be encountered, and if it runs from before backwards, from left to right, and if the anterior fontanelle is towards the right sacro-iliac symphysis, the position must be left occipito-iliac anterior. But if the anterior fontanelle is found to be at the left ileo-pectineal eminence, the position must be right occipito-iliac posterior. Either fontanelle, anterior or posterior, may be ascertained by tracing along on the sagittal suture each way, backwards or for wards. In this manner are all the positions of the vertex presentations ascertained.
The mechanism of labor where the position is with the occiput in the left half of the pelvis, is usually the same in all cases. The occiput being left anterior, transverse or posterior, the contractions having begun and the liquor amnii having partially escaped, the first effect upon the child is to flex the head more perfectly upon the chest, which constitutes the first stage in mechanism of labor. This has the effect to bring the long diameter of the head in harmony with the axis of the superior strait. The second stage is completed when the head descends into the cavity of the pelvis till its crown presses upon the plane of the pelvis. The third stage and rotation is accomplished from left to left to right, till the progress of the head is arrested by the back of the neck resting upon the symphysis pubis. During the fourth stage, extension of head upon the neck takes place, and the head is born by the occiput slipping up in front of the symphysis pubis, and the perineum retracting from over the forehead, face and chin of the child. Now the fifth and last stage in the mechanism of labor is accomplished, by the shoulders rotating into the long diameter of the inferior strait, which produces external rotation of the head, and the child is delivered.
It will be observed that the external rotation of the head is not an isolated fact, but that it is in consequence of the shoulders rotating in the inferior strait; and that this corresponds to the previous rotation of the shoulders in the superior strait simultaneously with this rotation of the head in the inferior strait. The face in these positions always appears on the right thigh of the mother. The right, or anterior shoulder is the first to appear in the fissure of the vulva; but the left, or posterior shoulder, is thee first to be set free by means of the perineum retracting from it, and it is thus in reality born first.
Thus mechanism of labor, the occiput being in the right half of the pubis, whether it be anterior, transverse or posterior, is all same usually as that just described. The same stage are passed through, but the rotations are not all from right to left; and consequently the face will appear at the thigh of the mother, instead of the right, as in the former case. When the occiput is at the right iliac sacral symphysis, it should always rotate to the front and appear under the arch of the pubis, precisely the same as when it is at the left sacro-iliac symphysis, which it sometimes fails to do, but slips into the hollow of the sacrum and remains behind till the completion of the labor, when the forehead appears under the arch, and the occiput is first disengages at the posterior commissure of the vulva.
It sometimes happens that when the occiput is in the hollow of the sacrum, the heed becomes gradually extended and the presentation becomes converted into one of the face.
Inclined, or irregular vertex presentations are usually aided in recovering a regular presentations by changing the mother’s position upon the same side of the inclination; thus if the sagittal suture is inclining far upon the right side, by tuning the patient upon the right side, the child’s body will fall down upon that side, and the inclination be rectified at once.
After the birth of the child, if inspection is made at once, it is always easy to tell the position it occupied from the sero- sanguineous tumor upon that part which presented. For the presenting part not being in contact with any thing, and pressure being made upon other parts, the fluids are forced into this parts; all of which soon subsides after the birth of the child. This sero-sanguineous tumor need not be mistaken for the cephalhaematoma; for the former exists at birth, the latter does not appear for some hours after; the former is large and purple; the latter smaller, the skin not discolored, it is fluctuating or pulsating and has an osseous border. The sero-sanguineous tumor does not exist if the child perishes long before birth, from which fact a medical jurist can draw an important inference in fixing upon the time of the death of a newly-born child