A System of Midwifery

by Edward Rigby

“Not long after the first edition was at press, indeed before the first sheet was printed, Levret’s dissertation on this subject fell into my hands, and in a note I referred to it as additional testimony in proof of the placenta, in these cases, being originally attached to the os uteri.

“I have been led into this little detail, because it has been suggested that I have borrowed my theory from Levret. After remarking the gross folly I should have been guilty of in quoting Levret, had I furtively adopted his opinions, it will, I trust, be sufficient for me unequivocally to declare that my original ideas on the subject were derived solely from my own personal observation and experience; and that having previously neither read nor heard of the placenta being ever fixed to the os uteri, the knowledge of such a circumstance, derived as before observed, came to me and impressed me as a discovery.

“I was, certainly, afterwards struck with the coincidence of the sentiments of Levret and myself on the subject, with the similarity of our practical deductions, and, allowing for the difference of language, even with the sameness of our expressions. I am farther not reluctant to acknowledge, that after reading Levret’s dissertation, I felt less entitled to the claim of absolute originality on the subject; and I now rest perfectly satisfied to divide with him the credit arising from the mere circumstance of communicating a new physiological fact. But were I even denied all claim to originality, I should still not be without the satisfaction of having, at least, materially contributed to diffuse the knowledge of an important fact, and of having established its practical utility on the unequivocal testimony of experience; for, had I seen Levret’s dissertation sooner, or had even my attention been first directed to the subject by its perusal, ought it to have superseded my publication? Was the practice in this country, at that time, at all influenced by Levret’s dissertation? or has it even since been translated into the English language? Was it, at that time, generally known that the attachment of the placenta to the os uteri was a frequent cause of hæmorrhage? and were any directions for our conduct in these cases, founded on the knowledge of the fact, given by those who there lectured on the art of midwifery?

“Levret’s facts, moreover, though they proved that the placenta might be originally attached to the os uteri, (and a single instance would establish this,) were scarcely sufficient to prove the frequency of its occurrence, from which alone arises the necessity of practically attending to it in every case of hæmorrhage. His observations (perhaps even more creditable to him for being founded on such scanty materials) were derived from four cases only, and of these, but two were under his own immediate cognizance; whereas, in the first edition of this essay my opinions were supported by 36 detailed cases, in 13 of which the placenta was found at the os uteri; and in the fourth edition the number was increased to 106, 43 of which were produced by this peculiar original situation of the placenta.” (Preface to the 5th ed.)

The causes of this peculiar deviation from the usual situation of the placenta are little if at all known. The condition of the decidua shortly after the entrance of the ovum into the cavity of the uterus, will probably influence the situation of the placenta considerably. Under the ordinary circumstances, this effusion of plastic lymph has already attained such a degree of firmness and coherence as to prevent the ovum from passing beyond the uterine extremity of the Fallopian tube from which it has emerged; but in cases of placental presentation it may be presumed that at this period the decidua was still in a semi-fluid state, had formed little or no attachment to the walls of the uterus, and had, therefore, no effect in preventing the ovum gravitating to the lower part, or even to the mouth of the uterus itself. We state this, of course, as a mere matter of theory, since the difficulty of investigation at such early periods, and the comparative rarity of placental presentations, will probably ever prevent our ascertaining the real cause.

Symptoms. The first symptom which warns us that the placenta is presenting, is the sudden appearance of hæmorrhage, which is usually more copious than ordinary hæmorrhage, and apparently comes on without any assignable reason: it is usually the more profuse the nearer the patient is to the full term of pregnancy, for not only now are the ruptured vessels larger, but the separation of the placenta is generally greater. If she has still some time to go, the discharge will be probably slight, and with rest and quiet, &c., will cease, to return again in ten days or a fortnight with increased violence: this usually happens at what would have been a catamenial period. The suddenness of its attack, the profuseness of the discharge, and its coming on without any evident cause, are peculiarly suspicious.

It has been stated that the abdomen is less distended in these cases than usual, from the placenta not being in the upper parts of the uterus: it is an observation, however, which requires to be confirmed, and certainly our own experience, as yet, has not led us to such a conclusion.

On examination, the os uteri is found to be larger and thicker than ordinary: it has a loose spongy feel, for its vessels are now as immensely distended as those of the fundus, when the placenta has its usual situation. If the placenta be partially attached over the os uteri, it is generally upon the anterior lip, which is much thicker. In this case we shall feel the edge of the placenta projecting at one side of the os uteri, and the bladder of membranes, and probably the presenting part of the child at the other. Whereas, if the placenta be centrally attached, we shall find it attached to the whole circumference, except perhaps where the separation is, from which the hæmorrhage proceeds. We shall distinguish the placenta by its spongy mass, by its soft irregular surface, and by the stringy feel which it communicates where it has been torn.

The character of the hæmorrhage is also different from that of common hæmorrhage, inasmuch as it increases during a pain, and diminishes or ceases during the intervals, whereas, in hæmorrhage under ordinary circumstances it is the reverse.

Where the hæmorrhage takes place at some distance of time from the full period of utero-gestation, it probably arises from the gradual development of the cervix during the latter months of pregnancy: where, on the other hand, it does not appear till just before labour, the separation of the placenta will have been produced by the incipient dilatation of the os uteri itself. It might therefore be supposed, that the period of the attack would, in great measure, depend upon whether the placenta was centrally, or only partially, attached to the os uteri; that in the former case the placenta would be more liable to be separated by the gradual development of the inferior segment of the uterus; and that, therefore, hæmorrhage would come on several weeks before the full term; whereas, if only a portion of it cover the edge of the os uteri, the patient would probably go to the very end of pregnancy before any flooding appeared. Although this view is supported by the high authority of Professor Naegelé, still we can scarcely agree with it, since not only do a considerable majority of recorded cases show that a patient with central presentation of the placenta may go to the full time without an attack of flooding, but also several of those which have come under our own observation lead to a similar conclusion.