From two and a half to three and a half months the conditions are still more different. The placenta has been definitively formed, it is relatively larger than the fcetus, it is attached more firmly to the uterus. In case of accident or of hemorrhage, the ovum will no longer separate entire, but only by portions from the uterus. Therefore miscarriage in two stages becomes the nile, and in one the exception. The uterus is far from having acquired its definitive structure, the muscular fibres are still in a rudimentary condition, and hence, the uterine contractions are too feeble to detach the placenta. Whence the infinite duration of the process, at times. Furthermore, there is marked disproportion between the dilata tion of the cervical canal and the body which has to pass through it. The cervix, indeed, still neither dilates nor retracts; whence, again, the likeli hood of rupture of the membranes. Under the influence of contractions, the internal os opens, the ovum enters the c,anal, and remains there for a number of days. Then, at a given time, as a result of a contraction, or of some effort on the part of the woman, the ovum ruptures, and the em bryo is expelled through the cervix, and often breaks the cord; if not, the embryo remains attached to the cord until traction, or effort of the woman, breaks it. The placenta stays in the uterus, and, whether sepa rated or not, a new labor is necessary for its expulsion. The cervix closes, and new contractions are needed to re-open it for the passage of the pla centa. If this organ has entirely separated, hemorrhage is ordinarily not abundant, except at the time of expulsion; if separation be incomplete, the hemorrhage lasts until detachment has occurred. In any case, no effort should be made to remove it, before its engagement in the cervix, otherwise, there is risk of tearing it, and of leaving portions in the uterus, and still another labor will be necessary for the expulsion of the remnants; and if this new labor should not supervene, the placental shreds may putrefy, and, 9.13 we will see, entail grave complications.
The above is not all. There is another element which we must remem ber, and this is the decidnal membrane. In labor at term this membrane is really decidual, because it has lost its vitality; but in miscarriage, it is still living, and adheres strongly to the uterus; and instances are not rare where miscarriage is divisible into three stages, one for the fcetus, one for the placenta, one for the uterine mucous membrane.
Very infrequently, in our opinion, the ovum is expelled entire at this period of gestation, and then the fcetus is dead.
From three and a half to the seventh month, miscarriage approaches, progressively, nearer in character to labor at term. Two stages are the rule. The muscular fibre of the uterus is more developed, the uterine mucous membrane is detached the more readily, and while considerable time elapses between the expulsion of the fcetus and that of the placenta, this interval is relatively less. It is exceptional t,o see the expulsion of the placenta delayed beyond twelve t,o twenty-four hours. The nearer to the seventh inonth the less profuse the hemorrhage; but even up to the fifth month, it may be very considerable.
Such are, in outline, the phenomena of miscarriage at various stages of gestation. We now consider, in detail, each of these phenomena, the hemorrhage, the uterine contractions, the modifications of the cervix.
Uterine is intimately connected with miscarriage, and if every hemorrhage does not determine the process, we may, never theless, say that there can occur no miscarriage without hemorrhage. The very structure of the ovum, even during the first months, necessi tates this. Immediately at conception, the ovum becomes surrounded by vascular villi, its detachment is, therefore, necessarily accompanied by hemorrhage. Again in case of premature detachment of the ovum, the separation occurs but slowly, and here is another source of bleeding. The appearance of hemorrhage, therefore, in the early months of preg nancy, should always awaken the anxiety of the acconcheur. In the vast majority of cases, it is an indication of impending miscarriage.
[It is well to recall further causes of hemorrhage, slight in amount usu ally, during the early months of pregnancy. Up to the sixth or eighth week it is still allowable to think of a return of the mensea At a later period, although there are a few undoubted instances on record, men struation can hardly occur without imperilling the ovum. Frequent causes of hemorrhage are, slight separation of the ovum, the result, not infrequently of violent or often repeated coitus, erosions of the external os, cervical polypi or tumors, carcinoma of the cervix, lacerations of this organ. The point we desire to insist upon is that in every instance where a gravid woman complains of hemorrhage, both a digital and specular examination should be made to determine if one or another of the above causes be not at the bottom of it, instead of impending miscarriage.—Ed.] This hemorrhage is sometimes preceded by signs of uterine congestion, sometimes is sudden in appearance. It may be internal, external, or mixed. " When the hemorrhage is internal, it may be limited to the membranes, to certain portions of the placenta, constituting what has been called placental apoplexy. It may then, if slight, not determine quickly either labor, or the expulsion of the fcetus, or its death. One or another of these result only after the repetition of such hemorrhage. In other instances, it may be profuse, and may spread throughout the entire placenta, the whole ovum separating without the appearance of the least blood externally." (Jacquemier.) The precursory signs of miscarriage, it is understood, are more or less intense, according to the amount of separation of the ovum, which fol lows on the hemorrhage. The uterus, distended by blood and clots, be gins to contract, and this contraction becoming more frequent, the cervix opens, and the clots, with a little fluid blood, pass out. The hemor rhage has become external. • When the hemorthage is external, it may begin by a simple trickling of a reddish fluid, only becoming later hemorrhagic in character, or else announce itself at once by the appearance of clots and blood. Some times the blood is black, followed only later by red. The duration of the flow is variable. It may begin with the miscarriage and persist continu ously to the end; again it may appear only with the contractions. At times it ceases not to recur until the expulsory act, and then profusely. The amount lost is very variable, from a few drops on. It comes, we believe, from both the arteries and the veins, and as a result of the rup ture of the mucous membrane and detachments of the placenta, which leave open the uterine sinuses. The blood, hence, is rather venous than arterial.