The Invention of The Forceps

On 3 July 1569 there disembarked at Southampton a Huguenot refugee family by the name of Chamberlen (Chamberlayne, Chamberlaine and Chamberlin are other spellings). The family consisted of William the father (whether he ever practised medicine or was qualified to do so has not been determined), his wife and three children. Two other sons were born a year and 3 years, respectively, after the family had settled in England. The eldest and the youngest son were both named Peter and are referred to by obstetric historians as ‘Peter the older’ and ‘Peter the younger’. To add to the confusion there was a third Peter, a son of Peter the younger, known under the designation ‘Dr Peter Chamberlen’ because he was Doctor of Medicine at Padua (1619), Oxford (1620) and Cambridge (1621) and a Fellow of the College of Physicians (1628); while the father and uncle were of the Barber Surgeons Company (date of admission round about the years 1596–8). Further reference to these three Peters will be under the respective numbers I, II and III which some historians have very wisely adopted for the purpose of distinguishing them.

For many years the invention was attributed to Peter III (Dr Peter Chamberlen), who was born in 1601 and died in 1683. This impression, however, is almost certainly refuted by his own statement: ‘My Fame begot me envie and secret enemies which mightily increased when my Father added to me the knowledge of “Deliveries and the Cures of Women”.’ There is therefore every justification for concluding that the inventor of the obstetric forceps was either Peter I or Peter II, or possibly both.

Peter I (1560?–1631) attained the greater distinction and his rise to fame was as dramatic as it was rapid. He attended Anne of Denmark, Queen Consort of James I and other notable women in society in their confinements. And for so doing as a Barber Surgeon he was arraigned before the College of Physicians in 1612 and incarcerated in Newgate Prison. By the intervention of the Queen and the Archbishop of Canterbury, the President and Censors of the College were prevailed upon to permit his release.

Peter II (1572–1626), the brother, some 10 or 12 years younger, was also interested in midwifery and he was the first to suggest the creation of an Incorporation of Midwives, a project with which Peter III, his son, was more particularly identified.

The probability is that Peter I was the inventor and that the date of the invention was shortly before or shortly after 1600. There is of course the other remote possibility that if ‘Old Father William’ did practise medicine, as some historians thought was the case, he may have been the actual inventor of the instrument.

The secret was kept in the family for 100 years or more. But many attempts were made – presumably the secret was beginning to leak out – to trade the instrument in Paris and Amsterdam by Hugh Chamberlen Senior (son of Peter III), who possessed all his father’s combativeness and business instincts, coupled with his ability to retain a position at Court and amongst numerous clients in the highest social scale. Historical was his encounter with the great obstetrician Francois Mauriceau (1637–1709) in Paris in 1670 when, to test the value of the forceps, Mauriceau gave him a rachitic dwarf (who had been many days in labour) to deliver. Of course, Chamberlen failed and Mauriceau chuckled! Yet, like all commercial travellers, so little was he abashed by his failure that within 6 months we find him again in Paris, on this occasion attempting to sell the invention to the French Government.

It was not until the 18th century was well advanced that the secret of the forceps became known. It was first announced by Edmund Chapman (1680?–1756), the obstetrician of Essex and London, who publicly made known the forceps used by the Chamberlens.

Space does not permit, nor is the occasion suitable, to pursue here the story of this most remarkable family and its doings; nor to describe the schemes – medical, political and commercial – which they sponsored. Fortunately, in Aveling’s historic volume we possess a complete record of all these details and of what perhaps was the crowning event in the romance of the forceps, the discovery in 1818 of a number of the Chamberlens’ instruments ( Fig 10-1 ) in a well-concealed chest in Woodham Mortimer Hall, Essex, which had been purchased by Peter III round about 1630 and continued in the possession of the family until 1715.

Chamberlen’s forceps.

On the death in 1728 of Hugh (Junior), son of Hugh (Senior) and grandson of Peter III, the male line of the Chamberlens became extinct. He too was a popular obstetrician and physician and carried on a most successful practice amongst the highest classes of society of London. As far as can be judged, he shed the aggressive enthusiasm, commercial instincts and timely sanctimoniousness of his forebears. He mellowed, was popular with the fellows and was three times elected a Censor of the College of Physicians. He is commemorated in the cenotaph in the north aisle of the choir in Westminster Abbey erected by the son of his patron the Duke of Buckingham, no doubt at the instigation of the Duchess, with whom he lived on intimate terms following the death of the Duke. Thus is the story of the family rounded off by these events!

The forceps of the Chamberlens – admittedly those illustrated here were early patterns – was simple in design and possessed only a cephalic curve, and in this form they remained for well over 100 years (1600?–1747).

The Introduction of The Pelvic Curve

To André Levret (1703–1780) is attributed this improvement, which he brought to the notice of the Paris Academy in 1747. As is often the case, other individuals came up with the same idea at about the same time. Benjamin Pugh (1715–1798), an obstetrician in Chelmsford, Essex, claimed, in the preface of his 1754 Treatise of Midwifery, ‘The curved forceps I invented upwards of 14 years ago…’ It is likely that about the same time William Smellie (1697–1763) independently conceived the same modification, but in respect of the design of the forceps it is mainly for the simplification of the lock (‘English lock’) that we are indebted to him. The lock Chapman designed was simply a slot in each blade and not nearly so secure as Smellie’s lock.

Incidentally, we would mention here that Smellie was the first to recommend forceps for the delivery of the after-coming head in breech extractions and it was largely because he found the straight forceps unsuitable that he invented a long double-curved forceps.

With the addition of this new pelvic curve the instrument was obviously more suitable for extracting a fetal head arrested high in the pelvis, but it still suffered from one of the chief faults of the long straight forceps: namely that when applied to a high head much of the traction force (a third to a half) was expended by pulling the head against the pubes.

The Introduction of Axis-Traction Devices

Etienne Stéphane Tarnier (1828–1897) will ever be honoured as the inventor of axis-traction forceps. But long before Tarnier described his instrument in 1877 it had been fully appreciated that, even with the long double-curved forcep, traction in the axis of the pelvis was impossible and that a great deal of the force exerted by the operator was lost by the head being pulled against the anterior pelvic wall. Levret, Smellie and Baudelocque, for example, in order to obviate this, gave directions how traction was to be made as far back as possible. Charles Pajot (1816–1896) of Paris popularized the manoeuvre to assist this posteriorly directed traction ( Fig 10-2 ). Although known as Pajot’s manoeuvre it was first described by the Danish obstetrician Mathias Saxtorph (1740–1800).

Pajot’s manoeuvre.

With the object of obtaining traction in the axis of the pelvis, many alterations and additions to the ordinary double-curved forceps were suggested in times past. One of the earliest – that of Saxtorph – was the use of bands through the fenestrae of the blades. A century later this suggestion reappeared in the recommendation of Poullet to pass cords through holes made immediately below the fenestrae of the blades; in more recent times Haig Ferguson once again recommended this primitive device.

As far as can be ascertained, the suggestion of having special traction handles was made first by Hermann of Berne in 1844. But the rods in Hermann’s forceps were employed on the same principle as that by which Saxtorph and Pajot effected their manoeuvres. Hermann’s device seems to have been forgotten, if, indeed, it ever became very generally known.

An important step in the evolution of the instrument was Hubert’s traction bar, described in 1860, for by it traction could undoubtedly still be exerted in the axis of the pelvis. Still later, the ends of the handles were bent backwards in a wide perineal curve. Alternatively, a detachable traction handle incorporating a perineal curve was applied to either the upper or the lower ends of the handles – some patterns recently employed (Neville-Barnes, Haig Ferguson) have the latter arrangement. It is perfectly evident to everyone that, in employing the ordinary forceps with the head at the brim, a large amount of force is dissipated against the anterior pelvic wall: Tarnier estimated that nearly half the traction force was lost. With axis-traction forceps this is avoided in greater part. The mechanics of axis-traction forceps were very carefully con­sidered by Tarnier and by Milne Murray. To those interested in this now historical subject we would commend the writings of those two authorities.

The Introduction of Straight Forceps for Rotation of The Fetal Head

The Norwegian obstetrician, Christian Kielland (1871–1941), designed straight forceps without a pelvic curve to facilitate delivery from the mid-pelvis in cases of malrotation with occipito-transverse and occipito-posterior positions of the fetal head. In fact, William Smellie had used the same principles of rotation almost two centuries before. Kielland laid down very precise rules for the use of his forceps which could be more correctly applied than forceps with a pelvic curve to the incompletely rotated fetal head in the mid or upper pelvis. In 1928, Lyman Barton (1866–1944), a rural general practitioner in New York State, developed straight forceps with a hinged anterior blade to facilitate application to the fetal head arrested in the transverse position at the pelvic brim. Arvind Moolgaoker later modified the Kielland forceps to incorporate a distance-spacing wedge between the handles to maintain the parallel positions of the forcep blades around the fetal head. Kielland’s forceps enjoyed considerable use in the middle part of the 20th century and continue to be applied in some hospitals for arrested occipito-posterior and occipito-transverse positions in the low–mid-pelvis.

The Vacuum Extractor

The history of the vacuum extractor is much shorter but its use is increasing, so that a majority of assisted vaginal deliveries are now performed using this instrument as opposed to the obstetric forceps. The vacuum principle was probably first applied in medicine with a cupping-glass to treat depressed skull fractures in infants and adults. The first attempted obstetrical application was in 1705 by James Yonge, surgeon to the Naval Hospital in Plymouth, England. He unsuccessfully attempted to deliver a fetus ‘by a cupping-glass fixt to the scalp with an air pump’. Neil Arnott (1788–1874), a Scot who received his education in Aberdeen and London, practised medicine in London and outlined the principles of a pneumatic tractor. There is no evidence that Arnott used his tractor for clinical purposes but he did propose its application in obstetrics: ‘Now it seems peculiarly adapted to the purpose of obstetric surgery, viz, as a substitute for the steel forceps in the hands of men who are deficient in manual dexterity, whether from inexperience or natural inaptitude’.

Some 20 years later James Young Simpson of Edinburgh (1811–1870), acknowledging the work of Arnott, developed a practical suction-tractor ( Fig 10-3 ). After his initial publications Simpson wrote no more on the subject and in the same year developed the obstetric forceps that bear his name and continue in use 150 years later.

Simpson’s air tractor. This early attempt to develop an instrument was hampered by an inability to produce sufficient negative pressure. The piston was of metal, the cup of wood and the rim was lined with leather which when wet allowed an airtight seal with the presenting part of the fetus.

(Property of the Department of Obstetrics and Gynaecology, University of Edinburgh).

The next century saw a number of attempts to apply the vacuum principle to assist vaginal delivery, but none achieved clinical utility. Tage Malmström of Sweden (1911–1995) was the father of the modern extractor. His unique contribution was a metal cup with an in-curved rounded margin. Thus, the peripheral margin of the cup attached to the fetal scalp had a narrower diameter than the upper margin, thereby producing a ‘chignon’ and effectively increasing the total surface area of application and reducing the risk of cup detachment during traction. Malmström introduced his prototype in 1953 with refinements culminating in 1957. Malmström’s cup had the suction and traction portions attached by one port in the centre of the cup. The English obstetrician Geoffrey Bird (1922–2001), who worked in Kenya, Australia and Papua New Guinea, made the next significant contribution to development of the vacuum extractor. He separated the traction and suction ports and emphasized the importance of accurate cup placement over the flexion point of the fetal head to minimize the presenting diameter. In order to facilitate placement of the cup over the flexion point in deflexed occipito-transverse and occipito-posterior positions Bird further modified the cup so that the suction port originated from the lateral margin. This so-called ‘posterior cup’ facilitated placement over the flexion point in the deflexed fetal head.

In the 1970s, in an attempt to reduce scalp trauma attributed to the metal cups, vacuum cups were manufactured with soft material. These softer cups did reduce the superficial scalp trauma but were associated with a much higher failure rate of achieving delivery, up to 25%, compared to a failure rate of < 5% with the metal cups. By the end of the 20th century, due to this high failure rate, vacuum cups were manufactured with harder plastic, and these continue in widespread use.