In the womb, the fœtus is folded together into a round oval form; and its usual position is with the head downwards, presenting at the upper brim of the pelvis, and at the mouth of the womb; the chin resting on its breast; one ear turned to the back part of the mother, the other forwards; the face and hindhead to the mother’s sides; the thighs bent up along the belly; the legs again bent backwards, with the heels to the buttocks; the arms laid along the infant’s sides, or before its breast. Thus folded together in a globular heap, it is wrapped up in four delicate transparent membranes, and is immerged in water, which continues decreasing throughout pregnancy, and at parturition is various in quantity, from one to six pints. By its blood vessels united into what is termed the navel-string, the fœtus is attached to a flat round cake, resembling a firm coagulum of blood, called the placenta, and which is closely cemented with the mother’s womb. In this natural posture the mature fœtus lays above the pelvis, and totally within the abdomen.
Previous to parturition, the fœtus must descend “inter scyllam et charybdin,” through that ossious circumvallation, or bony cavity of the mother, called Pelvis. This cavity is open, both above and below, and is inclosed between the hips, groin, and lower part of the spine. The female pelvis, for obvious reasons, is more capacious than in males. In a well formed and proportioned woman, the common standard is at the upper part of the brim, from the back part of the spine, or sacrum, four inches and a half; laterally, or from side to side, five inches and a half; below, at the lower opening of the pelvis, these dimensions are exactly reversed. But as in parturition, the os coxcygis, or lower bone of the spine, is elastic and moveable, on pressure backwards by the infant’s head, the diameter of the pelvis below is thereby enlarged in all its dimensions. The ossious depth of the pelvis, from the top of the os sacrum to the extremity of the os coxcygis, is five, or five inches and a half; at the sides four; before, or in the interval between the groins, two inches. In some deformed and ricketty women, the dimensions of the pelvis are either throughout, or in particular parts, greatly contracted, and most commonly at the upper part.
Of Parturition natural, laborious, preternatural, complex, or anomalous.
Natural labours are all those in which the infant’s head presents at the orifice of the womb; which are probably ninety-nine out of every hundred labours. But in this presentation of the infant, some are natural and easy, and a small number lingering and difficult labours. Preternatural labours are either all those wherein any other part of the fœtus spontaneously presents at the orifice of the womb, or where, notwithstanding the natural presentation of the head, yet it is necessary to turn the infant by force, and to deliver it by the feet foremost. Complex and anomalous labours are those, whether natural or preternatural, accompanied with extraordinary symptoms and danger, such as floodings, convulsions, &c.
Labour or parturition is a salutary effort of nature, to expel the contents of the womb by its own muscular contraction, and the collateral assistance of the muscles of the abdomen, diaphragm, thorax, back, and extremities. These exertions commence at intervals, called Paroxisms, or Labour Pains, which are various in strength and duration, from one to several minutes, and recurring at irregular intervals of one minute, an hour, or more. The symptoms naturally preceding and accompanying real parturition are, anxiety, shivering, violent pains, shooting from the loins to the lower part of the abdomen or womb, and extending down to the thighs; trembling of the thighs and legs; frequent micturition, tenesmus, diarrhœa, and involuntary stools, colick; the countenance and visage florid and red from the violence of the muscular efforts, with profuse perspiration and sweats; softness of the breasts, sinking of the abdomen in size, gradual dilatation of the orifice of the womb, protrusion of the membranes through its orifice in the form of a soft gut or bladder: in the absence of the labour pains the membranes and waters are retracted, at length are ruptured, when the fœtus may be felt with the finger introduced: next ensue the spiral descent of the infant’s head through the pelvis, dilatation of the external parts round the orifice of the vagina, expulsion of the infant, its membranes and waters; separation of the placenta, exclusion and extraction, together with some sanguineous discharge. Natural labours are generally terminated within a few hours, from 2 to 12 of real labour efforts; sometimes in a few minutes, and with a trifling exertion or pain. In some warm climates labours are alledged to be particularly easy.
But there are specious, or False labour pains, which are vague and irregular in frequency and force, and do not produce any sensible enlargement of the uterine orifice, and are not attended with any mucous discharge: they are generally confined to the lumbar region and abdomen, without extending down the thighs; they are most troublesome towards night, and are relieved by clysters and opiates. They generally are excited by one of the following causes, stretching of the womb, erect posture, spasm in the intestinal canal, colick, costiveness, distention of the bladder with urine, &c.
Of laborious, lingering, tedious, or difficult parturition. Every labour in which the process is prolonged beyond 24 hours, may be classed under this head, notwithstanding the natural presentation of the infant. Sometimes the labour may continue several days, either from the head not entering the pelvis, or, which is much more frequent, from some impediment during its descent through that ossious cavity. In these cases the woman becomes hot, thirsty, anxious, restless, low-spirited; is afflicted with headach, nausea, sickness, vomiting, incontinence, and difficulty of urine; she tosses incessantly, and finds no comfort in any posture. During this struggle, the infant’s head advances slowly, or stops at various parts in its descent; and the intervals of labour paroxisms are various. It is by no means necessary that childbirth pains should be incessant, or without intervals of respite and rest. In some cases, tedious and difficult labours may continue two, three, and even four days and nights, when, after reiterated paroxisms, the infant may at length be excluded by the efforts of nature alone: in some of these cases also, the mother’s recovery is surprisingly expeditious, as if she had been delivered in half the time; and unless some dangerous symptoms indicate, no manual assistance will be necessary. It is an obstetrical axiom, that in labours with the head presenting, the labour pains continuing strong, the woman not deformed, the pelvis sufficiently capacious, the constitution sound, not exhausted by labour pains nor weak, there is the strongest reason to expect that nature will be adequate to the task of delivery.
Indeed, the obstetrical cases, where instruments are required, are very rare; and in such emergencies there is often much greater difficulty to determine the ultimate propriety of employing instrumental aid, than in the mode of using the few implements peculiar to the obstetrick art; consisting principally of forceps, crotchet, and scissars. The danger of the mother, from tedious and difficult parturition, is discernible from her natural constitution, her debility, pulse, respiration, voice, countenance, the duration of the labour, the weakness of the pains, or their perseverance and severity, the space elapsed from the entrance of the head into the pelvis, and from the rupture of the membranes. The danger of the fœtus may be predicted from the time its head has been pressed into the pelvis, and the violence of that pressure, especially on the yielding cranial bones.
Preternatural labours are these wherein any other parts but the infant’s head present at the orifice of the womb; such as the feet, breech, shoulders, arms, and so on; besides those other cases in which, although the fœtal presentation may be natural, yet, for variety of reasons, and in dangerous emergencies, it is necessary to turn the infant in utero, and to extract it by the feet. The signs of the preternatural position of the fœtus are uncertain, until the accocheur can touch the presenting part. But in all cases, natural and preternatural, before the rupture of the membranes and evacuation of the waters, it is often extremely difficult to distinguish by the finger what part is felt. Preternatural postures of the infant may be suspected, if the pains from the beginning are lingering, tardy, weak, making little impression on the orifice of the womb, consequently tedious labours; if the membranes are either soon ruptured, or are pinched up into a conical form, like the finger of a glove; if no part of the infant can even be touched until the uterine orifice is moderately dilated, which remains high up in the pelvis, and when any part of the fœtus can be reached, it is indistinct and irregular, and generally small.
In some preternatural presentations delivery may be easy; but in general, they are always precarious, often difficult and troublesome to the mother and accocheur. After some continuance of labour the membranes break; but still no bulky part descends, nor is the mouth of the womb sufficiently dilated: at length the labour pains abate in strength and frequency; sometimes they intermit during a few hours, and, in some instances, a day or more. When we compare the size of the fœtus and of the pelvis, the reason is obvious why in cross postures, where the infant descends double, and is expelled by the natural efforts of the mother, such cases will be difficult, especially in first labours; and unless the child is very small, it will often be born dead. It is true, Providence has wisely provided, as far as possible, against puerperal compression, by the softness of the buttocks, belly, and shoulders, and by the over-lapping of the parietal bones of the infant’s head. Infants in the womb, we may presume, are subject to diseases as well as casualties; but probably the most frequent causes of mature abortives and stillborn, originate from laborious, preternatural, and complex parturition; which cases, as we observed, may be estimated at about eight per cent.; but the abortives and stillborn are not altogether three per cent.