Winckel, who admits this effect of uterine obliquity, believes that face presentations are more easily produced when the back of the child is turned to the right aide. He has collected 376 cases of face presentation, and has arrived at the following conclusions: 1. Face presentations occur almost as frequently in primiparaa as in multipara.
2. One-third of the primiparie that have them are aged, and have passed the ago of twenty-six years.
3. It is rare to see successive face presentations in the same woman, save in cases of contracted pelvis.
4. Multipare that have face presentations have already had faulty pres entations; i.e.. have an abnormal shape of the uterus, or difficult labors.
5. Contractions of the pelvis are often coincident with face presenta tions.
6. Multiparty, with pelvis contracted to the second and third degrees, have face prescntaticiis oftener than have primiparx with contracted pelvis.
7. The presentation M.I.R. is to that of M. L L. as 7 is to 5.
8. Face presentations entail longer labors than do those of the vertex.
9. They need interference oftener.
10. In fifteen per cent. of the cases the change into a face presentation occurs during labor.
11. Infants born by the face are above the average weight.
12. They are more often stillborn, thirteen to fourteen per cent. being so delivered.
13. Not unfrequently bands of the cord cause the death of the child.
14. The membranes are often prematurely ruptured.
15. Prolapse of the cord is relatively frequent, occurring in 2.25 per cent. of the cases.
16. Face presentations are equally frequent in all countries, and occur about once in 150 births.
17. The presentation of the face is never determined by a single cause, but by the union of two or three predisposing ones. The most frequent of these causes are: contractions of the pelvis, size of the infant, small quantity of liquor amnii, a pendulous abdomen, and uterine obliquity with contraction of the pelvis.
Hecker attributes face presentations to exaggerated development of the occiput. The occipital protuberance lengthens the arm of the pos terior lever, so that the uterine contractions cause the occiput to recede. The head see-saws, the occiput ascends, the chin is lowered, and the face presents. Budin, however, has proved that this dolicho-cephalicism is only secondary, being caused during delivery, and that it disappears with greater or less rapidity after birth.
Schroeder believes that the occiput offers a greater resistance than does the forehead, and that the latter descends, though situated at the end of the longer lever. Fasbender lays great importance upon the volume of the foetus, and Winckel and Pinard grains as the average excess of weight of face over ordinary presentations.
Finally, a number of authorities, and especially Matthews Duncan and Winckel, have called attention to the effect of faulty conformation of the pelvis. Winckel, in 400 face presentations, found eighty-seven cases of contracted pelvis. With Tarnier, Chantreuil and Pinard, we do not be lieve that the influence of this deformity is as great as is claimed, for other causes are usually active. Uterine obliquity is generally very marked in these cases.
Martel believes that face presentations are caused by external shock. An abrupt muscular contraction of the abdominal wall is not able to effect a complete change in the relations of the foetus to the uterine cavity, but it can change the relation of the head to the abdominal strait when the accommodation of form and direction, for some cause, such as a pelvic contraction, cannot occur.
, We believe ourselves that it is impossible to attribute face presentations to any one cause; for as Winckel has shown, the causes are often multiple. In his 376 cases he found pelvic contractions, large infants, small quanti ties of liquor amnii, pendulous abdomen, uterine obliquity, in fact every thing that prevents the normal accommodation of the foetus, to be the ordinary causes of face presentations. Ahlfeld has studied each of these causes separately, and has arrived at the following conclusions: The causes of face presentations are primary in primipane, primary and secondary in multiparse. Separating then, as all the German authors do, forehead presentations from those of the face, and admitting even primary and secondary forehead presentations, these causes according to him, are as follows: 1. Face Presentation—Primary Causes--Primiparm.--a. Tumors of the neck and upper portions of the thorax. Congenital strums. b. Bands of the cord around the neck. c. Stricture of the uterus, the com pression occurring at the region of the neck. d. Exaggerated develop ment of the head and thorax as compared with the normal length of the fcetus. Increase of the total foetal weight. e. Absence of neck in the foetus. f. Dolicho-cephalicism, the volume of the chest being normal, or over. g. Shortness of the cord, which, dragging from before backwards, brings about extension of the head. h. Twin pregnancies, the two foetuses lying longitudinally, or the one lying longitudinally, and the other transversely. i. Acrania or hemicephalia.