Obstetric forceps kept secret by a single family for over a century
An obstetric instrument of paired metal spoons that grip the head of the foetus made it possible to extract a live child in obstructed labour where before there remained only the hook and the death of the child.
The invention is credited to the English man-midwife Peter Chamberlen the Elder (around 1600). The family used the instrument for four generations and showed it to nobody: the labouring woman was blindfolded, onlookers were sent out, the forceps were brought in inside a closed box and carried away in a covered carriage. The secret spread only in the early 18th century, when Hugh Chamberlen the Younger was left without male heirs.
This is a rare documented case in which a working piece of knowledge existed and for more than a century went nowhere.
Why this date
disputed. There is no exact date and there cannot be one: the instrument was never printed, shown or patented, so there is no first documented application. The invention is credited to Peter Chamberlen the Elder (d. 1631). Sheikh, Ganesaratnam and Jan write of a secret kept for «nearly a century», Banoub, Hill and Bonello of a hundred-year run and of the secret leaking in the early 1700s; the family's original instruments were found only in 1813 under the attic floorboards of their house in Essex. The axis value of 1600 is a conventional point inside the period to which the invention is assigned, not a date taken from a document.
What grew out of it
-
Smellie: printed rules for applying the forceps and teaching midwifery on a machine
improved · Confidence: medium
Smellie reworked the already existing Chamberlen instrument: he added the English lock, fenestrated blades and a pelvic curve, and in 1752 printed the rules for applying it, turning a family secret into a teachable technique.
Dispute: The explicit statement of descent («to the existing design by Chamberlen») was found only in a museum catalogue entry, not in a peer-reviewed historical work. Sheikh and co-authors and de Costa describe Smellie's innovations in detail but do not say that what he reworked was the Chamberlen instrument specifically. In Sheikh there is an intermediate link between the Chamberlens and Smellie: models of forceps appearing from the early 18th century, including the lever design of the Van Roonhuysen family. A direct line from the Chamberlens to Smellie is therefore not proved; what is proved is only that Smellie reworked an instrument already in use.
Link sources
- «Obstetrics Forceps», Worcester Medical Museums (2023) Verified 20 Sep 2026
Smellie added an English lock and fenestrated blades (unlike this very early pair) to the existing design by Chamberlen.
- Sheikh S., Ganesaratnam I., Jan H. «The birth of forceps», JRSM Short Reports 4(7) (2013)
His instruments included the 'English lock' to allow the blades to be inserted separately into the vagina and also introduced a pelvic curve
- Sheikh S., Ganesaratnam I., Jan H. «The birth of forceps», JRSM Short Reports 4(7) (2013)
The rules of applying forceps were developed by Smellie and in 1752 he published the 'Treatise on the Theory and Practice of Midwifery'.
- Banoub M., Hill M., Bonello J. «Childbirth's hidden revolution: The origins of obstetric forceps», Hektoen International (2025) Verified 20 Sep 2026
It was not until the early 1700s when the family secret was finally revealed through Hugh the Elder's son, Hugh the Younger.
"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.
- «Obstetrics Forceps», Worcester Medical Museums (2023) Verified 20 Sep 2026
Node sources
- Sheikh S., Ganesaratnam I., Jan H. «The birth of forceps», JRSM Short Reports 4(7) (2013)
the Chamberlens were able to keep the secret of forceps for nearly a century.
- Sheikh S., Ganesaratnam I., Jan H. «The birth of forceps», JRSM Short Reports 4(7) (2013)
The instruments themselves were always carried in a gilded chest and revealed once the woman had been blindfolded.
- Moore W. «Keeping Mum», BMJ 334(7595), p. 698 (2007), 698 Verified 20 Sep 2026
The Chamberlens were clever businessmen. They advertised their services and shielded their invention from rival eyes by transporting the forceps in a covered carriage and carrying them into the delivery room in a huge box.
- Banoub M., Hill M., Bonello J. «Childbirth's hidden revolution: The origins of obstetric forceps», Hektoen International (2025) Verified 20 Sep 2026
It was not until the early 1700s when the family secret was finally revealed through Hugh the Elder's son, Hugh the Younger.
- Banoub M., Hill M., Bonello J. «Childbirth's hidden revolution: The origins of obstetric forceps», Hektoen International (2025) Verified 20 Sep 2026
Without any male heirs to carry the family tradition, Hugh the Younger allowed the family secret to leak.
"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.
Further reading
Not evidence: these carry no quotation and support nothing we wrote. They are books and scans to read next.