The use of the obstetric forceps

T HE obstetric forceps, like the automobile, may be indispensabIe, if properIy used, in the saving of Iife and human effort and suffering; and, improperIy used, it may be the instrument of many unnecessary deaths. There are six principles essentia1 to the safe and successful use of the forceps: I. The cervix must be fuIIy diIated, that is, its passage must be Iarge enough to shp over the head at the pIane of maximal diameters without retarding pressure. It is very easy to Iet one’s obstetric conscience sIip in this direction untiI, by degrees, it becomes habitua1 to appIy the forceps when the cervica1 passage Iacks 2 or even 4 cm. of compIete diIatation. It shouId be remembered that a rim of cervix I cm. wide diminishes every diameter of the passage by 2 cm. Dragging the head through this inadequate opening resuIts at least in Laceration of the cervix, and at most, in fata intracrania1 strains and resultant hemorrhage. 2. The forceps must be properIy apphed. It may be diIIicuIt (in rare cases, impossibIe) to appIy the forceps symmetricahy to the head, but repeated attempts shouId be made unti1 the sagitta1 suture coincides with the vertical pIane of the forceps. Failure to effect this adjustment accounts for most of the cases of sIipping of the forceps. ProperIy appIied, it is aImost impossibIe (impossible within the justifiabIe Iimits of force of traction) to puI1 the forceps off the head. Improper appIication results in a mechanica maladjustment somewhat Iike using the wrong wrench on a boIthead-the wrench is aImost certain to siip, or to hoId onIy because of damage to the boIt. Pressure injuries to the soft parts of the feta1 head may be inevitabIe; but gashes and tearing off of ears, Iips, etc., shouId never occur. 3. Force in the appIication and adjustment of the forceps is never permissibIe. If diffrcuIty is encountered, something is wrong-the position of the head has changed, the forceps has sIipped outside of the cervix instead of inside it, the blade has caught against an ear or some other prominence, or the whole route of the introduction of the bIade has been wrong. Proper introduction of the forceps involves a knowIedge of the topography and axis of the birth cana1, and requires a technique of Ietting the bIade foIIow the line of Ieast resistance (as in sounding of the urethra). Any attempt at forcibIe steering is apt to Iead the top of the bIade into a hopeIessIy bIocked situation. It is better to dislodge the head and change its position than to attempt to force the forceps past any serious obstacIe. 4. The head shouId never be compressed by squeezing on the handIes of the forceps. It is very easy, in making traction, to appIy great IateraI pressure on the head by invoIuntary squeezing. Once a snug and accurate ht. of the bIades has been accompIished, nothing is gained by further compression : in other words, excessive compression adds no security against sIipping. 3. Force in extraction shouId never be empIoyed. It is diffrcuIt to estimate the tractive force which one employs in actual practice, so that dynamometric figures are of no great practica1 vaIue. Force sufficient to move the patient on the tabIe is excessive. Moderate traction wiI1 cause the peIvis to sIide on the fat of the buttocks, so that, especiaIIy in obese individuaIs, the apparent to-and-fro movement of the peIvis may be quite great; but the buttocks