It is important in this connection to consider the conditions existing at the angle of flexion. In many cases of so-called flexion, there is sim ply a bending of the anterior or posterior uterine wall. The vertical axes of the cervix and body of the uterus merge iuto each other at the os internum. When the body of the uterus lies forward we then have purely an exaggeration of Schultze's normal position, that is only a tran sitional stage to the corresponding version, a condition that would be best designated us a curvature, and not as a flexion. In other cases an angle is present, but it is obtuse, being greater than 90°, and this also repre sents only the transition to a normal position. ill case of these changes in shape, conception is rendered more difficult, but they are not to be considered as pathological flexion changes. The sharper the angle in the latter cases, however, the more likely sterility and the longer the in terval before conception ensues. Further, it is of importance as to whether the flexion is present in a nullipara or in a parous woman. If au equally well-marked flexion exist in both, conception is a little more apt to occur in the latter. This is probably due to the fact that the ntems having once been distended, the os internum is larger and stenosis consequently less marked. The spermatozoa can moro readily hence enter the uterus; and further in the latter case, the cervix having under gone a process of softening, it is therefore less resisting and the stenosis more easily overcome. An essential obstacle to conception in a case of flexion is further offered by changes in position of the cervix. This is specially the case with anteflexion, where (with or without a previous pos terior cellulitis having existed), as has already been pointed out, the cervix instead of pointing downwards and backwards is directed forwards. Here the angle of flexion is very acute, and stenosis is extremely marked. Of importance also is the complicating endometritis, which soon follows ca flexion of the uterus, if it does not already exist, or has been acquired, as is frequently the case.
In addition to the stenosis there is also present a mechanical and chemical obstacle in the cervical canal, or when the semen has found its way past the os internum, the impregnated ovum does not find a suitable soil for its further development. The most important complications are pelvic cellulitis and pelvic peritonitis, in particular their residues. They are especially liable to bring about a change of form in the acquired caws of flexion. They are likewise an effective obstruction to conception, as has already been pointed out, and often are also the cause of the failure of the mechanical course of treatment. To consider these processes, however, as the sole causal factors of the sterility, I think from the above considerations is not warrantable. In many instances the stenosis ac companying the flexion is more marked at different times. Thus there are cases in which the uterus, as the result of marked relaxation, becomes strongly retroflexed, and then after a short time thiEi changes into an anteflexion, and further alterations of flexions into versions may be met with. Of greater importance, however, is the overcoming of the stenosis at the menstrual periods. There is no question that during menstruation, or immediately before or after it, the uterine sound can be more readily introduced than in the inter-menstrual periods. This is probably due to
enlargement, resulting from the congestion with the consequent erection of the body of the uterus, by reason of which the angle of curvature is diminished, and the flexion temporarily rectified; but it is more probable that because of the softening of the stenosed portion, the pressure of the uterine walls is less, and at the same time a dilatation of the canal takes place, as is the case in pregnancy where there is great congestion and serous infiltration. It is essential to take this temporary relaxation into account in the course of treatment.
Of the different varieties of flexion, the congenital anteflexion is as frequently accompanied by sterility as the rarer retroflexion of the nulli para. Even P. Grenser, who has specially studied the latter variety, con cedes this point as regards the frequency of sterility. In my experience, WI regards the unproductiveness resulting from flexion, I find that con ception occurs least frequently with anteflexion, and not with retroflexion, where it occurs more frequently, even as in the corresponding version. The rare congenital lateral flexion has always been considered as a cause of sterility—at least this condition has been found relatively frequent in sterile women, both during life and at autopsy. As regards acquired latero-flexion, which has recently become better understood, insufficient data exist to warrant an opinion. Concerning the worst change of form in the uterus, inversion, it is self-evident that conception cannot take place when this is even only moderately marked. Even if the semen and ovum come into contact, which is possible when only a slight degree of inversion exists, yet the accompanying conditions are not conducive toward farther development. In only a single instance (Dibardes) was impreg nation followed by a cure of the inversion, and here the possibility that a spontaneous reducticm of the inversion occurred before conceptiou is not ruled out.
Reliable statistics of the changes in shape of the uterus, as regards ste rility, are as yet difficult to formulate, the old statistics,which include many cases of curvature and of normal flexion, making the percentage of flexion too great. Still flexions are responsible for sterility in a fair proportion of cases. It seems to me that the figures which Leopold Meyer gives, are very near the truth. As the result of the examination of many infants, be has determined the normal position of the uterus, and considers an angle of flexion from 140° to 160° to be normal, and in 227 cases of ste rility he found 21 instances of primary and 24 of acquired anteflexion, and 4 of primary and 26 of acquired retroflexion. Judging from the material at my disposal, which exceeds that of Meyer, although I am un able to give a detailed classification, since I cannot separate the pure cases from those with complications, the primary anteflexionsare comparatively more frequent than the acquired; as regards the comparative frequency of retroflexion, my tables are incomplete. I think tbat many of these cases, even as are many acquired anteflexions, have been classed under the chronic inflammations which often complicate these flexions. The other deviations in form of the uterus are, because of their rarity, dis carded in statistics.