A System of Midwifery

by Edward Rigby

In women who have had several children, it is frequently impossible to reach the presentation during the early part of the labour: this arises either from the abdomen in these cases being generally more or less pendulous, or from the circumstance of the uterus having been distended in so many previous pregnancies: its lower part does not become so fully developed as before, but continues more or less funnel-shaped, a considerable portion of the cervix still remaining. Where this is the case, the head will not descend so low as usual at first, but remains out of reach, or nearly so, until the os uteri is fully dilated and the membranes have given way.

“If, upon such an examination, it should be ascertained that the os uteri is considerably dilated, and the child cannot be felt, this affords reason to suspect that the presentation is preternatural. Should the liquor amnii be discharged and the child be out of reach of the finger, the probability of a preternatural position is greater. Should the membranes be found hanging down in the vagina not of the usual globular form, but rather conical and small in diameter, this likewise is a presumptive proof of a cross-birth; especially if there be any part presenting through the membranes which is smaller, feels lighter, or gives less resistance when touched than the bulky heavy head.”[109]

The diagnosis of the shoulder is by no means easy: it offers no distinctive marks, and may readily be mistaken for the nates, or even for the head. It feels round, but is smaller and softer than the head. The scapula and clavicle, the neck, the armpit, the arm itself, and the ribs, assist us in our diagnosis. From the direction of these parts, we shall be able to ascertain the position of the rest of the body, and which shoulder presents. If the hand has prolapsed, the direction of the palm and of the thumb will soon show the position of the child.

Labours with malposition are always dangerous; when left without assistance, they are almost always fatal to the child, and generally so to the mother.

When a full-grown child has presented with the arm or shoulder, and nothing has been done to assist the delivery of it, the results are usually as follow:—After the membranes have burst, and discharged more liquor amnii than in general where the head or nates presents, the uterus contracts tighter around the child, and the shoulder is gradually pressed deeper into the pelvis, while the pains increased considerably in violence, from the child being unable, from its faulty position, to yield to the expulsive efforts of nature. Drained of its liquor amnii, the uterus remains in a state of contraction even during the intervals of the pains; the consequence of this general and continued pressure is, that the child is destroyed from the circulation in the placenta being interrupted, the mother becomes exhausted, and inflammation or rupture of the uterus or vagina are almost the unavoidable results.

Another although much rarer consequence of malposition of the child, is that peculiar mode of expulsion which was first noticed by Dr. Denman in 1772. From the supposition that the shoulder receded and the nates came down into the pelvis, in which position the child was born, he called it “the spontaneous evolution of the fœtus;” but the term spontaneous expulsion, as proposed by Dr. Douglas in 1811, is much better adapted, it having been shown by that gentleman that the explanation of this process as given by Dr. Denman was not correct. (An Explanation of the real Process of the spontaneous Evolution of the Fœtus, by J. C. Douglas, M. D. 2nd ed. 1819, p. 28.,) but that whilst the shoulder rested against the pubes, the side of the thorax and abdomen, followed by the nates, passed in one enormous sweep over the perineum, leaving the head and other arm still to be extricated.

The shoulder and thorax thus low and impacted, instead of receding into the uterus, are at each successive pain forced still lower, until the ribs of that side, corresponding with the protruded arm, press on the perineum, and cause it to assume the same form as it would by the pressure of the forehead in a natural labour. At this period, not only the entire of the arm but the shoulder can be perceived externally, with the clavicle lying under the arch of the pubes. By farther uterine contractions the ribs are forced more forwards, appearing at the os externum, as the vertex would in a natural labour, the clavicle having been by degrees forced round on the anterior part of the pubes with the acromion looking towards the mons Veneris. “The arm and shoulder are entirely protruded with one side of the thorax, not only appearing at the os externum, but partly without it: the lower part of the same side of the trunk presses on the perineum, with the breech either in the hollow of the sacrum or at the brim of the pelvis, ready to descend into it, and, by a few farther uterine efforts, the remainder of the trunk, with the lower extremities, is expelled.” (Douglas, op. cit. p. 28. 2nd ed.)

Farther experience has confirmed the correctness of Dr. Douglas’s views (Med. Trans. of the Royal Coll. of Physicians, vol. vi. 1820;) and, indeed, the original case as related by Dr. Denman himself tends to prove that nothing like an “evolution” of the fœtus takes place. I found the arm much swelled, and pushed through the external parts in such a manner that the shoulder nearly reached the perineum. The woman struggled vehemently with her pains, and during their continuance I perceived the shoulder of the child to descend.

Some years afterwards, the late Dr. Gooch had the opportunity of observing a case of spontaneous expulsion with great accuracy, and came to the same conclusion as Dr. Douglas had done. “Resolved to know what became of the arm, if this (the spontaneous expulsion) should happen, and thus fit myself for a witness on this disputed point, I laid hold of it with a napkin and watched its movements: so far from going up into the uterus when a pain came on, it advanced, as well as the shoulder, still forwarder under the arch of the pubes, the side of the thorax pressing more on the perineum and appearing still more externally; it advanced so rapidly that in two pains, with a good deal of muscular exertion on the part of the patient, but apparently with less suffering than attends the birth of the head in a common first labour, did the side of the chest, of the abdomen, and of the breech, pass one after the other in an enormous sweep over the perineum till the nates and legs were completely expelled.” (Ibid.)

The celebrated Boer, has, however, detailed a case where the arm had prolapsed into the vagina, the hand appearing externally; and on introducing his hand for the purpose of turning, he felt the hand distinctly receding, and the breech beginning to occupy the cavity of the pelvis. This is very different to a case of spontaneous expulsion: “the child lay completely across, with its abdomen towards the back of the mother;”[110] it had, in fact, not yet begun to press against the brim, or to assume any definite position, there having been as yet but little uterine contraction, and both rectum and bladder being considerably distended. When these were evacuated the pains increased: the breech being nearest to the brim, descended, and the arm in consequence receded. Dr. Gooch considers it most probable that “it was only a breech presentation, the hand having accidentally slipt down into the vagina.”