It is seen at once that this differs from premature labor, which meand the expulsion of the product of conception before term, but where the fcetus is viable. In this respect accoucheurs differ from the rulings of the law. The latter states that the fcetus is viable after the sixth month, while the former contend that it is not so till the seventh. It is our belief, then, that miscarriage consists in the expul sion of the ketus during the six first months of pregnancy. This fcotus may be born dead or alive, but its development will not admit of life--it is not viable. In certain exceptional cases, fcetuses of less than seven months may live, but these cases are of such rarity that we are justified in the division which we have made. Before seven months, therefore, miscarriage; after seven months, premature labor. To the exceptional cases which have been recorded, we can add another. A woman last menstruated the tenth of March; was delivered the twenty-eighth of September, that is to say, twelve days before the seventh lunar month. The child survived.
Although we make this division, it should be understood that miscar riage from the third to the fourth month is a very different affair from miscarriage at the fifth or sixth month. While during the early months, the first three in particular, the phenomena of miscarriage are special and peculiar, from the fourth month on, these phenomena approach more and more in character labor at full term. Struck by these peculiarities, the older writers, and certain modern, (we would instance, in particular Guillemot), made three divisions of miscarriage: 1. Ovular miscarriage. 2. Embryonic. 3. Fcetal. Why this division? It is because each cor responds to a certain stage of development of the ovum, and such distinc tion, while subtile, has, practically, certain advantages.
Ovular miscarriage includes the first three to four weeks of the life of the ovum.
Embryonic miscarriage extends from the end of the first month to the end of the third.
Fcetal miscarriage from the fourth to the seventh month Coincidently, indeed, with the development of the ovum, it unctergoes modifications in structure, which necessitate infinite differences in its expulsion; and even as we were able to say of labor at term, that not one resembled the other, the same may be said of miscarriage. When we
study the phenomena of miscaniage, we must remember that we are dealing with a number of factors. Kunecke, in Germany, makes four: 1st. Mechanical modifications. 2d. Organic. 3d. Dynamic. 4th. Plas tic. We.make of these, two: The moclifications which concern: 1st. the ovum, 2d. the uterus.
On the side of the ovum these modifications are enormous, from the day when it arrives, as a new organism, in the womb, up to the end of the third month; so great, indeed, that it is impossible to compare the ovum of the first, second, and third month.together.
During the first month, the ovum, engrafted on the uterine mucous membrane, which swells around it, so as to constitute what is termed the decidua reflexa, is surrounded entirely by the villi of the chorion, which develop over its surface. It is composed already of its two membranes, the amnion and the chorion, and the uterine mucous membrane may be decomposed into three portions, parietal decidua, decidua reflexa, and mucous membrane between placenta and ut,erus, or, better still, between uterus and ovum. There is still no e,avity in the ovum. It is being formed.' When removed from the decidna, the ovum looks like a small body roughened by the projection of a number of appendages, one longer than the others, at the centre of which is found the amnion, containing the microscopic embryo, so to speak. This little ovum is surrrounded by a second membrane, thicker, and more voluminous, in which it is almost lost, and which is no other than the uterine mucous membrane, in two portions, the one applied directly to the ovum, the decidua reflexa, the other larger, and separated from the former by a space filled with gelatin ous matter, more or less liquid, and this is the parietal mucous mem brane. This gelatinous matter, which disappears later, is the hydroperion. The whole is surrounded by clots, more or less dense.