MALFORMATION OF THE GENITAL ORGANS.
As Schroeder properly says, the only malformations of the female geni tal organs that interest the obstetrician, are those which do not interfere with pregnancy. Now, conception is possible whenever normal ova are expelled from the ovary, and when the canal traversed by the ovum or the spermatozoa, from the ovary down to the vaginal outlet, is at no point absolutely impermeable.
I. Malformations of the Uterus.
Modern researches in embryology have shown that the genital organs are formed at the expense of the Wolffian body and its excretory canals, andller's ducts, the latter being transformed into the uterus and Fal lopian tubes. Geoffroy Saint-Hilaire and others showed that there are three stages of development, viz.: 1. Separation and complete division. 2. Approximation and reunion in the median line. 3. Complete fusion.
Thiersch was the first to prove that the uterus and vagina are formed by the fusion of Muller's ducts, the upper portion becoming the tubes, the lower, the uterus and portio vaginalis. The rectum and bladder are eventually separated from the uro-genital canal by an anterior and poste rior spur that, later, form the recto- and vesico-vaginal septa. The ex ternal genitals are formed, after the internal have become partly developed, by the disappearance of the tissues placed between the rectal cul-de-sac, the vagina and the bladder on one side, and of the integument on the other, the three cavities communicating with the exterior of the body. This explains all the malformations that occur: for example, if the rectal cul-de-sac is not opened, imperforate anus results; if the tissue that closes the vaginal canal is not absorbed, more or less complete obliteration, or even absence, of the vagina is produced. • 1. Mullet's ducts may remain in contact at their point of entrance into the cloaca, but remain separate above, forming two distinct uterine cavi ties, each of which has a single tube connected with it; there are thus two uteri, each of which has its cervix, and a single tube and ovary at tached to it (uterus duplex.) 2. The ducts may unite below, but remain separated above (uterus bicornis.) 3. The junction may occur at the normal point, but the fundus may remain undeveloped, having a median cleft which gives to it the appear ance of a heart (uterus cardiformis.) 4. The ducts, instead of developing, may atrophy, resulting in the complete absence of the internal genital organs; this atrophy may be limited to that portion of the ducts which is destined to form the body of the uterus, the appendages developing normally (uterus deficiens), or a. single duct may atrophy, resulting in a deficiency of one horn. of the uterus (uterus unicornis.) 5. The septum which separates the united ducts may persist, so that the uterus contains two distinct cavities (uterus sepias, bilocularis, bi partitus); or, the septum may be absorbed below, but may persist at the fundus (uterus subseptus, semi partitus.)
6. The arrest of development may affect the vagina as well as the uterus, so that the canal may be wholly or partly double, or absent.
It is evident that some of these malformations absolutely prevent con ception, but that pregnancy may take place in a one-horned, or double, uterus. Pregnancy may occur either in the well-developed, or in the rudimentary horn, and that too although the neck of the latter is closed (Fig. 131). Schroeder explains this by supposing that the semen has been able to pass up the tube which connects with the well-developed horn, enters the peritoneal cavity, and crosses over to the opposite ovary, where it fecundates the ovum which has been grasped by the tube of the imperfect horn; or a fecundated ovum from the ovary corresponding to the normal cornu may cross to the opposite tube. According to Scanzoni and Schroeder, the course of the pregnancy in this case bears the closest analogy to the extra-uterine variety. The rupture of the festal sac, with its fatal consequences, takes place at some time between the third and sixth month, the point at which the rupture occurs being the least de veloped portion of the horn. The normal horn takes part iu the forma tive activity, as shown by the hypertrophy and softening of the muscular tissue, the development of its vessels, and the growth of a decidua. The foetus may die and be transformed into a lithoptedion. The diagnosis is almost impossible in the living subject, and even in the cadaver it may be mistaken for tubal pregnancy (Fig. 131.) When pregnancy takes place in the well-developed horn it usually pro ceeds normally; the uterus has a crescentic form, and by palpation a small tumor has been felt attached to the organ by a short pedicle. The eccentric attachment and abnormal shortness of the portio vaginalis serve to confirm the diagnosis. Gestation may likewise occur in a double uterus, but abortion is more likely to follow. Simultaneous development of a foetus in each half of the uterus has been observed several times, and this proves that in ordinary twin-pregnancies one ovule may come from each ovary, and not both from a single one. Labor usually proceeds normally, but rupture of the septum, or even of the uterus, may ensue.
Grinow has collected fifteen cases of pregnancy associated with malfor mations of the uterus or vagina, two-thirds of the women being primi pane. Eight reached full term, two nine months. In two instances labor began with hemorrhage, as the placenta was attached to the septum. The uterine contractions were feeble, sometimes spasmodic, so that in terference was frequently necessary. Five of the women died.