External cephalic version is often performed late in pregnancy, or early in labor, in transverse and also in breech presentations, to secure a vertex presentation because of the high fetal death rate in breech extractions. Podalic version, or making the breech the presenting part, is often performed in transverse presentations, in placenta prævia and when the cord or extremities are prolapsed. Having converted the presentation into a breech, the usual breech extraction is performed.
Forceps are instruments which are used to extract the child when presenting by the head in certain conditions which endanger the life of mother or child. The value of forceps in obstetrics can scarcely be overestimated, as before their invention the only operative method of delivering a live baby was by means of version and extraction, and in these the fetal death rate was high. The obstetrical instruments in use up to that time, therefore, were all for the destruction of the child in utero.
Forceps were devised, and first used, in great secrecy, early in the 17th century, by a Dr. Chamberlen, in England, who jealously guarded all information relating to his invention from every one but members of his own family.
There were several doctors in the Chamberlen family who practiced obstetrics and who used these forceps, but knowledge concerning the nature of the instruments and methods of using them was not shared with members of the medical profession outside of that family, until the beginning of the 18th century. Since that time the use of forceps has been widely extended and the original Chamberlen instruments have been so modified and altered and improved by different obstetricians, that there is now a bewildering number and variety in existence and in use. Probably the most widely used are those which were devised by Dr. Tarnier of France and Dr. Simpson of England, respectively. (Fig. [107].) The Tarnier instrument is known as an axis traction forceps, and can be used in all kinds of forceps operations, while Dr. Simpson’s are suitable for use only in low forceps cases.
There are two groups of indications for the use of forceps; those relating to the condition of the child and those relating to the mother.
Fig. 107.—Two widely used forceps. A, Tarnier axis-traction forceps. B, Simpson forceps.
Indications for their use in the interests of the child are symptoms of asphyxia, and these are the passage of meconium, in head presentations, and a change in the rate or rhythm of the fetal heartbeat. As pressure on the abdomen of the fetus during labor, in breech presentations, is very likely to express meconium, this is not of special significance in these cases. But in head presentations, the escape of meconium suggests paralysis of the rectal sphincter muscles, due to imperfect oxygenation, which, in turn, is caused by interference with the placental circulation by pressure on the cord or premature separation of the placenta.
Conditions which menace the life of the mother, and indicate the use of forceps, are inadequate contractions of the uterine and abdominal muscles; exhaustion, as indicated by an increase in the maternal pulse rate or elevation of temperature, and in certain chronic and infectious diseases, when the patient may be unable to stand the strain of the second stage.
Forceps are usually employed when the head fails to make satisfactory advancement after two hours of good, second-stage pains, or when it remains in one place on the perineum for an hour, in spite of good, second-stage pains.