title: A randomized prospective study comparing delivery with metal and silicone rubber vacuum extractor cups.
abstract: OBJECTIVE
  To determine the relative benefits and complications of assisted vaginal delivery with metal and silicone rubber vacuum extractor cups.
  
  
  METHODS
  Prospective randomized controlled study.
  
  
  METHODS
  A busy referral maternity hospital in Kathmandu, Nepal.
  
  
  METHODS
  101 women were assigned to delivery with the Silc-cup and 98 to delivery with the metal cup.
  
  
  METHODS
  Success rate at achieving delivery with the assigned instrument and incidence of neonatal trauma. Analysis was by 'intention to deliver' with women remaining in their original group regardless of the eventual mode of delivery.
  
  
  RESULTS
  Randomization resulted in two groups of women similar in respect of age, parity, gestation and indication for delivery. The overall success rate was similar for the two instruments (Silc-cup 85% and metal cup 87%). The Silc-cup was more likely to fail if there was excessive caput (seven failures compared with one in the metal cup group). The frequency of clinically significant maternal trauma was low in both groups. There were fewer babies with clinically significant scalp trauma in the Silc-cup group (22%), compared with the metal cup group (37%).
  
  
  CONCLUSIONS
  The data indicate a greater tendency for the Silc-cup to fail when excessive caput is present but that metal cups are associated with increased scalp injuries.
authors.affiliation: Dudley Road Hospital, Birmingham, UK.
authors.forename: R
authors.initials: R
authors.lastname: Chenoy
authors.forename: R
authors.initials: R
authors.lastname: Johanson
mesh_terms: D000328:Adult; D001720:Birth Injuries / Q000209:etiology; D004868:Equipment Failure; D005260:Female; D006801:Humans; D007744:Obstetric Labor Complications / Q000209:etiology; D011247:Pregnancy; D011446:Prospective Studies; D016896:Treatment Outcome; D014620:Vacuum Extraction, Obstetrical / Q000009:adverse effects / Q000295:instrumentation*