THE LIQUOR AMNII, OR WATERS.
In order that you may the better understand the first stage of labor, I will here make some remarks on the nature and office of the fluid above-named. By liquor amnii, or waters, is meant that fluid which is contained within the membranes surrounding the child.
The quantity of the waters, when compared with the size of the child, is greater in the earlier parts of pregnancy. At the time of labor it is found to vary a good deal in different cases, amounting in some to four or five pints, and in others to scarcely as many ounces. It is thought to be largest in case the child has been for some time dead, as also when it is very feeble.
In regard to the office of this fluid, some have imagined that the fetus is nourished by it, the liquor being swallowed into the stomach. But in answer to this doctrine, it is to be remarked, that there are many examples of children having been born without any passage to this organ. There have also been born children of a full size and well-formed shape, all except the head, which was wanting. These facts make it clear that the child must be nourished in some other way than by the waters surrounding it.
Some also have supposed this fluid to be an excrementitious substance; but this belief is not now generally adopted, or rather, no physiologist of any eminence regards it as such at the present day.
The liquor amnii “is generally transparent, often milky, and sometimes of a yellow or light-brown color, and very different in consistence; and these alterations seem to depend upon the state of the constitution of the parent. It does not coagulate with heat, like the serum of the blood; and chemically examined, it is found to be composed of phlegm, earthy matter, and sea-salt, in different proportions in different subjects, by which the varieties in its appearance and consistence are produced.”
It has been supposed that the liquor amnii may, all of it, be discharged as early as the sixth month of pregnancy, without producing injury to either mother or child; but this cannot be true, it would appear, since it is well known, that when the membranes are broken intentionally, so that all of the waters are discharged, the uterus never fails to contract itself until abortion or the birth comes on. A discharge from the vagina, somewhat resembling the waters, however, may appear for weeks, and even months, before the delivery takes place; but in such cases it has been observed, that no diminution in the size of the abdomen occurs, from which circumstance it is known that the real liquor amnii does not pass off.
The normal purposes of this fluid in the system appear to be to afford the fetus a safe and easy lodgment in the uterus. If it were not there to protect the embryo, it would constantly be in danger of being destroyed by mechanical violence; besides which, it would be almost certain of adhering to the inner surface of the womb in such a way that the birth could not possibly take place. At the time of labor, too, we see the advantages of the “bag of waters,” for as it is protruded in advance of the child, it forms a soft, yielding wedge, as it were, which gradually dilates the soft parts, without overstretching or tearing them, which would not be the case if the comparatively hard head of the child was the first to present itself.
The rupture of the membranes, which ends the first stage of labor, may take place a very short time before the expulsion of the child, or it may happen prematurely, as it were; that is, many hours, or even days or weeks before the child is born. In such cases the occurrence is to be considered as an accident or exception to the general rule. It does happen, however, every now and then, and in many cases it seems to make no difference whatever in regard to the future progress and safety of the delivery.
The greatest agony, as I have remarked, is experienced at the time the child is brought into the world; but if I could make plain to you the mechanism of labor, you would be struck with admiration, I am sure, at the wonderful marks of benevolence and design which are exhibited in the manner in which a child is expelled from the uterine cavity.
You may ask why it is that a woman should be made to suffer pain at all in bringing forth a child, and why did not the Creator form the system of woman in such a way that a child could be expelled without causing any of that agony which is well known to be a natural circumstance of childbirth. I answer, it was not possible for God to create woman in such a way. Suppose He had made her pelvis larger, and the soft parts more yielding; she would have been constantly subject to the misfortune of miscarriage; or rather, it would not have been possible for her to carry a child at all.
But see the beautiful, and at the same time wonderful operation of nature in the mechanism of parturition. At first, some days before labor is to come on, the abdomen begins to subside, showing that the uterus, with its contents, is gradually sinking downward in preparation for the greater struggle that is to take place at the birth. Probably, too, the womb at the same time begins to contract itself more firmly upon the child, and, as it were, begins to gather strength for the contest which it is about to engage in, namely, that of forcing the child into the world. After this there appears a greater discharge of mucous than ordinary from the womb and vagina, which serves to soften and lubricate the parts in preparation for the terrible distension which is to take place. Gradually, also, in the first stage of labor, the womb dilates, for too sudden a distention of this important part would be very apt to cause a fatal rupture of the organ. In the second stage, the head of the child is driven through the os uteri into the vagina. As the pains continue, the face of the child is turned into the hollow of the sacrum; that is, toward the back of the mother, the wider part of the head being in the wider part of the pelvis, just as a wise mechanician would naturally place it; but in the beginning of labor, when the child’s head is at the upper part of the pelvis, it lies more to the side of the mother, corresponding to the wider diameter of this upper strait.
Look at a skeleton, I repeat, that bugbear of our childhood, that grim yet beautiful remnant of our mortality; and when you see and understand how admirably adapted the form and shape of the pelvis is to the ends for which it was created, tell me if you do not recognize in this adaptation the most unmistakable evidences of the work of an Almighty hand.
In cases of first children, the first or dilating stage usually occupies from six to thirty or more hours. It is natural to expect that a woman must suffer greater pain, and bear a more tedious labor with her first child than with the subsequent ones. “I have heard a voice as of a woman in travail, and the anguish as of her that bringeth forth her first child,” saith the prophet Jeremiah. The difference in the length of the first and subsequent labors, however, is not usually in proportion to the number of children that have been borne. If a woman be twenty-four or thirty-six hours in labor with her first child, she may be only six or eight with her second, and in the subsequent labors only three or four hours. There will, of course, be many deviations from any calculation of this kind that can be made, but the practitioner will, however, often be able to form a tolerably accurate opinion of the probable duration of a labor, if the woman have had a number of children previously. But even here there will be a good deal of liability to error, since the fifth, sixth, or tenth labor may prove a very tedious and difficult one, because of some mal-position of the child. I had an example of this kind in my own practice some months ago, in which a lady suffered incomparably more with the birth of her third child than with both of the former together, and the labor was protracted to thirty hours, which was a much longer period than either of the former had been. This happened in consequence of the face of the child, that is, the wider part of the head, presenting forward in the narrower part of the outlet of the pelvis, whereas in almost all cases the reverse of this takes place, as I before remarked. Such cases are, however, fortunately very rare, the exception only to the general rule.
You will readily understand why the first labor is apt to be somewhat more difficult than subsequent ones, when you recollect that all the soft parts, such as the womb, vagina, the external organs, etc., are more rigid and unyielding in the first labor than they afterward are. The bones, recollect, are the same at all times; they do not give or separate, as many of you have supposed; they are bound so firmly together that it is not possible for them to be separated, in their natural and healthful state, by any such force as that which is exerted in the birth of a child, although this force is a great one. It is necessary that the bones of the pelvis should be thus strongly bound together, otherwise they would not be sufficiently firm to answer the purposes for which they are intended.