title: A new obstetrical polyurethane versus stainless steel forceps: a comparison of forces generated to the base of the fetal skull during simulated deliveries.
abstract: BACKGROUND
  Decreasing the maximum force applied during traction to the base of the fetal skull using a less rigid polyurethane forceps is the basis of this study. Our hypothesis was that less force would be generated with polyurethane forceps than with steel forceps.
  
  
  OBJECTIVE
  To test a new soft polyurethane obstetrical forceps for maximal force generated to the base of the skull during simulated occiput anterior deliveries and to compare this to a similar shaped steel forceps.
  
  
  METHODS
  After designing a prototype polyurethane forceps, we used a pelvic manikin model and a fetal manikin model. Force and load sensors were attached at the inner tips of the distal forceps blade. A Tekscan 201 (accurate for measuring 0-25 pounds of force) 0.0008 inches flexible printed circuit was used that measured contact forces. Forceps with an attached calibrated sensor were applied to the fetal head while inside the pelvic model.
  
  
  RESULTS
  The median maximum traction force at the base of the fetal skull was 4.60 pounds (range 4.3-4.62) for polyurethane forceps vs. 9.52 pounds (range 9.22-9.52) for steel forceps (P=0.027).
  
  
  CONCLUSIONS
  The polyurethane forceps applied 50% less overall mechanical force than the steel forceps at the tip of the forceps and base of the skull during simulated occiput anterior outlet deliveries.
authors.affiliation: Department of Obstetrics and Gynecology, Lincoln Medical Center, Weill Medical College of Cornell University, New York, NY, USA. theoodore.hale@nychhc.org
authors.forename: Theodore M
authors.initials: TM
authors.lastname: Hale
authors.forename: Zhengzhuan
authors.initials: Z
authors.lastname: Shi
authors.forename: Hasitha
authors.initials: H
authors.lastname: Idangodage
authors.forename: Ray
authors.initials: R
authors.lastname: Mercado
authors.forename: Daniel
authors.initials: D
authors.lastname: Skupski
authors.forename: Zoila
authors.initials: Z
authors.lastname: Veilastegui
mesh_terms: D001696:Biomechanical Phenomena; D001720:Birth Injuries / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D036861:Delivery, Obstetric / Q000009:adverse effects / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D005333:Fetus / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D008348:Manikins; D009772:Obstetrical Forceps / Q000009:adverse effects; D011140:Polyurethanes; D011247:Pregnancy; D012886:Skull / Q000502:physiology*; D013193:Stainless Steel; D013314:Stress, Mechanical
chemical_list: D011140:Polyurethanes; D013193:Stainless Steel