A System of Midwifery

by Edward Rigby

“The more completely the os uteri is opposite the fundus, and the more the axis of the uterus corresponds with that of the pelvis, the sooner are the pains, cæteris paribus, capable of dilating the os uteri.” (Wigand, vol. ii. p. 273.) The cushiony state of the vagina and os uteri, and the free secretion of thick albuminous mucus from these parts, as already mentioned, will be of great importance in ensuring their easy dilatation. Where this secretion is either absent, or very scanty, the passages become dry, hot, and tender, from no relief being afforded to the congested vessels by its effusion; and vice versâ, where there is a febrile state of the circulation and considerable topical excitement, the secretion is sparing, or, perhaps, stops entirely. This state may arise from a variety of causes, such as from general plethora, too warm clothing, bad ventilation, derangement and irritation of the primæ viæ, and abuse of spirituous and other stimulating liquors: it may arise from constipation, or may be induced by rough and too frequent examination. The patient becomes flushed, excited, and feverish, with a hot skin, dry tongue, thirst, and headach; the uterine contractions become irregular, they produce much suffering, and but very little advance in the progress of the labour; the passages are in a state of inflammation, and more especially the os uteri, which is much swollen and excessively tender. The process of labour is completely interrupted, and can only be restored to a healthy condition by bleeding, warm bath, laxatives, and enemata.

Formation of the bag of the liquor amnii. When the os uteri has dilated more or less, a quantity of liquor amnii begins to collect between the head and the membranes, so that when a pain comes on they form a tense, elastic, and conical bag, which presses firmly against the os uteri, and protrudes through it into the vagina, and from its form and elastic nature greatly facilitates the speedy dilatation of it. If the edge of the os uteri be still thin, it will become so tense during the pain, and the bag of membranes will press so firmly against it, that we shall have some difficulty for the moment in distinguishing the one from the other. As the labour advances, the intervals between the pains become shorter, whereas the pains themselves are of longer duration and more effective. In this way pain succeeds pain until the os uteri, at length, attains its full degree of dilatation; if the membranes have not yet ruptured, we may now expect them to burst with every succeeding pain.

Rigour at the end of the first stage. At this moment the patient is occasionally seized with a sudden and violent fit of shivering, so much so as to make the teeth chatter, and even communicate a tremulous motion to the bed itself; this is not the result of cold, nor is it relieved by the application of external warmth; and, in many cases, the patient will express her surprise that she should shiver thus violently, and yet not feel cold. It appears to be a modification of convulsive action, excited by sympathy between the os uteri on its becoming fully dilated, and certain muscles in other parts of the body.

Show. On examination at this stage of the process, streaks of blood will be found in the mucus which soils the finger, and sometimes it amounts to a slight discharge of blood: this appearance is called by midwives “a show,” as it usually indicates that the os uteri is nearly or fully dilated. It is produced by a separation of the membranes from the vicinity of the os uteri, and consequent rupture of any little vascular twigs which may have passed from the uterus to them.

The full dilatation of the os uteri terminates the first stage of labour. During this stage, the action of the pains does not appear to have been so much for the expulsion of the child, as for preparing it as well as the passages for this purpose, viz. by so arranging and regulating the different forces of the uterus, and at the same time by giving the child such a position (i. e. with its long axis parallel to that of the uterus,) and the os uteri such a degree of dilatation, as shall ensure its expulsion with the greatest possible ease and safety.

Duration of the first stage. The duration of the first stage of labour varies exceedingly, both in primiparæ and those who have had several children; nor is it at all easy to determine with precision the exact moment when labour commences. The sensation of pain to the patient is no guide whatever, for what is attended with much suffering in one patient is scarcely sufficient to excite the notice of another. The dilatation of the os uteri as marking its commencement, must also be taken with some caution: in primiparæ, where it generally remains closed until the contractions are becoming painful, it would obviously be wrong to date the commencement of labour from the moment that the os uteri opens, as regular uterine contractions have been evidently present for some hours previously, although not of sufficient force to produce actual pain. On the other hand, in women who have already had several children, the os uteri is found open some days and even weeks before labour comes on. As a general rule, we may state that regular and genuine contractions of the uterus, sufficiently powerful to produce pain, seldom require more than six hours to effect the full dilatation of the os uteri; in many cases a much shorter time will be sufficient; whereas, in others, the first stage of labour may last for more than quadruple this period before it is completed: in neither can it be considered as abnormal; and we usually find that where the pains of the first stage have been slow and lingering, they become remarkably quick and active during the second stage. This agrees with the experience of Dr. Churchill, in his report of the Western Lying-in Hospital at Dublin, viz. that, “no evil consequences resulted, and they (the labours where the first stage was so protracted) were amongst those in whom the remaining stages of labour were shortest.”

The first stage terminates with the full dilatation of the os uteri; the rupture of the membranes is a change which is necessarily more or less uncertain, as to the precise period of labour at which it takes place. Thus, in primiparæ, it frequently occurs before the first stage is completed; whereas in other cases the membranes sometimes do not give way until the head approaches or has even passed through the os externum; generally speaking, however, they burst at this period of the labour, and usually effect a remarkable change in the whole process. The pains are now of longer duration and more powerful, the intervals between them are shorter, and yet, although the suffering is actually more severe, it is more tolerable to the patient than that of the first stage. During the first stage they are chiefly confined to one spot in the loins; and as they must necessarily continue for some hours without any distinct evidence of the labour being advanced by them, the patient feels discouraged and gets a little impatient at the endurance of so much apparently useless suffering: but as soon as the gush of liquor amnii takes place, she feels that a great alteration has been produced; the abdomen becomes smaller: the pains assume a very different character, and every thing combines to assure her that she has made progress, and encourages her to patience and resolution.

Description of second stage. The os uteri has now disappeared entirely, so that the vagina and uterus form one continuous canal, and is thus admirably adapted for the easy passage of the head: the anterior lip, however, dilates much more slowly than the other parts of it, and this is especially the case in primiparæ, for, being pressed between the head and pelvis it becomes œdematous, and swells to a considerable size: if the pains be strong, it is pushed down more or less before the head, and may be frequently felt beneath the symphysis pubis, and occasionally it is detruded so far as to be visible between the labia. According to Wigand, the swelling of the anterior lip sometimes attains such a size as makes it liable to be mistaken for the bladder of the membranes (op. cit. vol. ii. p. 308;) it seldom produces much obstacle to the advance of the head, and with a little patience gradually disappears of itself. All attempts to push it up above the head are objectionable, because, in the first place, the finger cannot reach sufficiently high to effect this object, and therefore the swelling descends again to its former situation; and, secondly, the efforts to push it up only tend to inflame it and increase the swelling. Those who imagine that they can push up the anterior lip of the os uteri above the head deceive themselves; and even if they do succeed, it merely shows that had they let it alone, it would have gone up very shortly of itself.

Straining pains. As the head enters the vagina, not only do the contractions of the uterus become much more powerful, but now another set of forces are called into action, and the half involuntary efforts of the abdominal and other muscles come to aid the uterus in expelling its contents. The sole object of this stage is the expulsion of the child, and even the vagina by its contractions contributes to effect it. The head is therefore subjected to considerable pressure; hence we may now feel the cranial bones overlapping each other at the sutures, and the fontanelles diminished in size; and, from the tightness with which the head is embraced by the vagina, the circulation in the scalp is more or less impeded, and a large œdematous swelling, called caput succedaneum, forms on that part of the head which presents.

Each pain is attended with a violent and irresistible impulse to bear down, and every muscle which can assist in effecting this object is now brought into play. The tone of the patient’s voice, the expression of her face, the hurried breathing and sudden inspiration, stopping short the moment a pain comes on, in order that she may add still greater power to the efforts which she is about to make, all betoken a very different process to that of the first stage, and one which requires a powerful struggle of muscular strength and energy for its completion. Hence it is that the sound of the patient’s voice during the pain is frequently of itself sufficient to inform us how far labour is advanced, for “we never see the really powerful straining pains come on (the head may be never so low in the pelvis,) so long as the os uteri is not fully dilated.” (Wigand, op. cit. vol. ii. p. 310.) This is a wise provision of Nature, for by this means it prevents the danger of laceration to which the os uteri would be otherwise exposed, and shows the importance of not permitting a patient to strain and bear down until the os uteri be fully dilated. In those cases where a patient has been induced to exert herself prematurely, the efforts being voluntary are never so powerful, and soon produce much fatigue.