Presentation of the Vertex.
1. Head at the Inferior Strait.—The forceps is superior to the lever, which pushes the head towards the coccyx, places it away from the centre of the vulva, and exposes the perineum to laceration. Only does the lever excel the forceps when the inferior strait is narrowed trans versely by the contiguity of the ischio-pubic rami, or the ischiatic tuber osities. Thanks to its little size, it is then easily applied, and can push the head backward where there is more room.
2. Head in the Cavity.—The forceps still excels the lever, for with it we may rotate the head, while in posterior presentations the lever would necessarily meet the face, and injure it greatly. Bodaert, nevertheless, has used it with success, but on the extended head, and when the anterior fontanelle was near the centre of the pelvis.
3. Head at the Superior Strait.—Tarnier is disposed to use the lever. The difficulty of grasping the head regularly, the impossibility of making traction in the desire ddirection, make him favor the lever, which is smaller than the forceps, and working only on the occiput, tends to flex the head, at the same time that it depresses it. Applied behind the pubes, it com presses the bead from before backward, while it elongates it transversely, or in the diameter which is not shortened. Tarnier, however, is not forgetful of the difficulty due to mobility of the head, and the danger of inflicting rupture or vesico-vaginal fistulae.
Presentation of the Face.
In the cavity or at the inferior strait, the choice should be the for ceps. At the superior strait, the lever might better direct the head into the axis of the inlet, and will reduce its size from before backwards. But here the lever requires more care than in case of the vertex, since it must be applied to the face, or to the occiput, and the injuries possi ble with the instrument are the greater the higher it is placed. We be lieve, therefore, that the forceps should be preferred.
Head retained after Extraction of the Body.
Coppe6 has, in particular, recommended the lever in these cases. We
have seen that, thanks to compression combined with traction and flexion, the forceps are not often needed, and the lever, therefore, would only ex ceptionally be required.
The lever then must remain an exceptional instrument. When used there is one absolute rule, and this is, if the occiput is in front or trans verse, apply the lever to it, or to the mastoid; if the forehead is in front, apply the instrument over the temple, so as to seize the brow or the sin ciput, according as it is deeply placed or not.
Not so bold as Tarnier, Jacquemier absolutely rejects the lever in occi pito-posterior positions, in the cavity, at the inferior strait, in face pres entations. He admits its utility at the superior strait with reserve. Re calling the experiments of Fabri and of Tarnier, he says, " We should judge too favorably of the solid grasp of the lever on the head, if we were to accept literally those experiments made in full view, where the point d' appui and the immobility of the head are assured beforehand, advantages Ahich we do not ordinarily possess. In case of pelvic deformity, how ever, where the forceps has failed, cranioclasty is not justifiable, neither is the Caesarean section if the child be alive, till we have tried the lever." These conclusions seem to us too favorable. To attempt, after repeated use of the forceps, to extract with the lever is to subject the woman to renewed injury, and likely enough not succeed in delivering the head. When the forceps is applied at the superior strait, it is only after a long labor, and when the waters have for long escaped. We interfere then either in the interest of the mother, and must deliver quickly and with the least possible violence, or else in those of the child whose life is in danger. To attempt with the lever, therefore, what the forceps has failed in accomplishing, seems to us worse than useless. Far better, we think, to sacrifice the child, and give the mother a chance by lessening the risk of injury through reduction in volume of the foetus.