A System of Midwifery

by Edward Rigby

There are two pieces of forceps, the long and the short forceps; the former for cases where the head is still high in the pelvis, the latter when it is at the pelvic outlet and approaching the os externum; the former with few exceptions being curved, the latter straight.[83]

The forceps act in three ways, 1. by mere pulling; 2. as a species of double lever, by moving the handles from side to side; and 3. by compressing the head, thus still farther disposing it to elongate and adapt itself to the passage through which it has to be expelled.

The blades should always, if possible, be applied one on each side of the head, the position of which must be determined by the direction of the fontanelles and sutures, not by feeling for the ear, as is usually recommended in this country. The ear can seldom be reached without causing a good deal of pain, even under the most favourable circumstances; in cases, therefore, where the head is so impacted as to be incapable of advancing by the natural powers, it cannot surely be justifiable to force up the finger between the head and the pelvis to ascertain this point, the more so, as the soft parts soon become swollen and more or less inflamed, and, therefore, little able to bear such rude treatment. No operation requires such an intimate acquaintance with the mechanism of parturition as that for applying the forceps: it is simple and generally perfectly easy when the precise position of the head and its relations to the pelvis are accurately known; on the other hand, it is not less injurious and painful to the patient than difficult and unsatisfactory to the practitioner.

The most usual circumstances under which the forceps is applied, are where the head is already deep in the pelvis and approaching the os externum; in such cases it is generally required not so much for the purpose of overcoming an unusual degree of resistance, as for assisting the natural powers, which are becoming exhausted: the head is near the os externum, and therefore easily reached; and from there being little or no impaction present, the blades are applied without difficulty.

The application of the forceps when the head is at the upper part of the pelvis, and where the greater portion of it has not yet passed the brim, is rarely practised in this country, because as the necessity for performing the operation at this stage arises in most instances from contraction of the brim, the perforator has usually been preferred, wherever the expelling powers have proved incapable of overcoming the resistance to the passage of the head. The circumstance also of this condition requiring the long forceps has been another source of objection, from the much greater power which this instrument is capable of exerting, and from its being therefore more liable than the short forceps to prove mischievous in the hands of the inexperienced.

Cases however do occur where there is but a very slight want of proportion between the head and pelvis, where the obstacle is easily overcome, and where, but for the application of the forceps, the labour would either have been protracted to a dangerous degree, or have required the use of the perforator.[84] “On the whole,” says Dr. Burns, “I would give it as my opinion that a well instructed practitioner, who has already had some experience in the use of the short forceps, is warranted to make a cautious, steady, but gentle attempt to apply and act with the long forceps in a case where he is not quite decided that the perforator is indispensable, and where the head is higher than admits the application of the short forceps.” (Principles of Midwifery, 9th ed. p. 493.)

In applying the forceps, whether short or long, there are two conditions which, cæteris paribus, are requisite in every case; first, that the os uteri shall be fully dilated; secondly, that the pains are within the bounds of what are commonly known as moderate pains. In the first case it will be very difficult and frequently quite impossible to pass the blades between the head and os uteri when only partly dilated; it will be difficult to avoid injuring its edge more or less, and if we do succeed in applying and locking the forceps, on making an extractive effort we shall find that the uterus descends with the head as we draw it down.

In the second place we ought never to apply the forceps whilst the pains are violent, for not only do they render its application difficult and even dangerous, but we are adding still farther to the force (already too great) with which the head is pressed against the pelvis. Where the head remains immoveable under violent exertions of the uterus, it is not a case for the forceps but for the perforator; nor does it admit of much delay, for it endangers much injury of the soft parts or even rupture of the uterus.

It is exceedingly difficult to assign any precise limits of pelvic contraction, within which the forceps can, and beyond which they cannot be applied, for the size and hardness of the fœtal head, the nature of the pains, and the condition of the patient must also be taken into account in every instance; hence, we frequently meet with cases where the pelvis is scarcely if at all contracted, and yet where the labour has been terminated with the greatest difficulty by means of the forceps; whereas, in others where we know the pelvis to be more or less deformed, the child has been delivered by the natural powers. This subject will be still farther considered under Dystocia Pelvica.

The general indications for the use of the forceps are two: 1. They are indicated in all labours which are difficult or impossible to complete, either from deficiency in the expelling powers, or from misproportion between the head and pelvis, or from the arm coming down with the head. 2. They are indicated by circumstances or accidental causes, which render labour dangerous for the mother or child, and where the danger can only be removed by hastening labour, as in cases of hæmorrhage, convulsions, syncope, alarming debility, faulty condition of the organs of respiration, danger of suffocation, obstinate vomiting, unusually severe pains in nervous irritable habits, hemorrhoids which have burst, hernia, retention of urine, determination of blood to the head, prolapsus of the cord, (in certain cases,) inflammation of the uterus, &c. (Naegelé, MS. Lectures.)