When the ovum descends, and the subsequent changes are beginning to take place, the body of the uterus comes also to form decidua; for I have formerly said, that, until the fœtus comes into the uterus, the fundus alone yields this production. At the same time, the processes of the decidua interna elongate still more, and, together with those which are now formed by the portion produced by the newly-formed decidua externa (for additional primary vessels imply additional secondary ones) at the lower part of the uterus, will come to fill up all the intervening space betwixt the bottom of the chorion or decidua reflexa and the cervical efflorescence; so that, by the end of the second or beginning of the third month, the cavity of the uterus is quite filled, and we have the ovum perfectly organized. We have the fœtus inclosed in its membranes, and swimming in water; we have the placenta thick and well formed, and large in proportion to the membranes; we have the decidua reflexa distinctly seen, and the lower part of the uterus filled with the two layers of decidua, and the processes of the internal one.
If at this time we take the ovum, composed of all these different parts, out of the uterus; or, if we cut off the face of the uterus, and remove the decidua from the front of the membranes, we shall see at the upper part the placenta and membranes like an old fashioned watch, the placenta resembling the case, and the membranes (when the decidua is taken off) the glass of the watch[[3]]; then, at the lower part of the membranes, we see the remains or margins of the decidua reflexa, which has been removed to shew the chorion; whilst, still lower down, we observe the decidua externa, and the processes of the interna, filling up the cervix and inferior part of the body of the uterus, forming a kind of firm stalk to the globe above. This stalk is thick, so as to occupy all the lower part of the uterus; but the layers and processes, furnished by the different sides, do not adhere when they meet in the axis of the uterus; but we have always a small canal or perforation leading up in the axes of the uterus from the cervical efflorescence, or the gelatinous plug, to the bottom of the decidua reflexa.
In proportion as the membranes enlarge and elongate, the decidua reflexa gradually protrudes before them down this canal, until at last it reaches the bottom; or, in other words, the membranes come to occupy all the uterine cavity.
Of the Manner in which Abortion takes place.
The process of gestation may be stopped, even before the fœtus, or vesicular part of the ovum, has descended into the uterus, and when only the primary vessels are formed. In this case, which occurs within three weeks after impregnation, the symptoms are much the same with those of menorrhagia. There is always a considerable, and often a copious discharge of blood, which coagulates or forms clots. This is accompanied with marks of uterine irritation, such as pain in the back and loins, frequently spasmodic affections of the bowels, and occasionally a slight febrile state of the system. In plethoric habits, and when abortion proceeds from over-action, or hemorrhagic action of the uterine vessels, the fever is idiopathic, and precedes the discharge.
In other circumstances it is either absent, or, when present, it is symptomatic, and still more inconsiderable, arising merely from pain or irritation. As the primary vessels are very small, and are soon displaced, they cannot be detected in the discharge. Nothing but coagulum can be perceived; and this, as in other cases of uterine hæmorrhage, is often so firm, and the globules and lymph so disposed, as to give it, more especially if it have been retained for some time about the uterus or vagina, a streaked or fibrous appearance, which sometimes gives rise to a supposition, that it is an organized substance. The discharge does not cease, when the primary vessels are destroyed, but generally continues until the small vesicle passes out of the fallopian tube. Then it stops, and an oosing of serous fluid finishes the process.
The only interruption to the discharge in this case of abortion, proceeds from the formation of clots, which, however, are soon displaced. Women, if plethoric, sometimes suffer considerably from the profusion of the discharge; but, in general, they soon recover.
When the secondary vessels are formed, the symptoms are still pretty much the same; but if the vesicle have descended into the uterus, they are somewhat different. We have an attempt in the uterus to contract, which formerly was not necessary; we have pains more or less regular in the back and hypogastric region; we have more disturbance of the abdominal viscera, particularly the stomach. The discharge is copious, and small bits of fibrous substance can often be observed[[4]].
Sometimes, when the vesicle has come into the uterus, before abortion takes place, it may be detected in the first discharge of blood, and will be found to be streaked over with pale vessels, giving it an appearance as if it had been slightly macerated. When all the contents are expelled, a bloody discharge continues for a few hours, and is then succeeded by a serous fluid at this time; and, in later abortion, if the symptoms come on gradually, we may sometimes observe a gelatinous matter to come away before the hæmorrhage appears.
If the uterus have been filled up, as in the beginning of the third month, the vesicle never escapes first; but we have for some time a discharge of blood, accompanied or succeeded by uterine pain. Then the inferior part or stalk of the ovum is expelled, gorged with blood, and afterwards the upper part equally injured. Sometimes the whole comes away at once and entire; but this is rare. As considerable contraction is now required in the uterus, the pains are pretty severe. The derangement of the stomach is also greater than formerly, giving rise to sickness or faintness, which is a natural contrivance for abating the hæmorrhage.