title: Risk factors for anal sphincter tears in vacuum-assisted delivery.
abstract: OBJECTIVE
  The aim of the present study was to describe the prevalence of anal sphincter tears (AST) in relation to obstetric management and technique during vacuum extraction deliveries (VE) (re: indications, the station of the fetal head at application of the cup, number of tractions, the length for the extraction, cup detachments, pain relief, episiotomy, fetal presentation, and experience of the operator) as well as maternal and infant anthropometrics.
  
  
  METHODS
  Descriptive study. Data on six hundred vacuum extraction deliveries were consecutively collected from six different delivery units in Sweden. Each unit contributed with data on 100 deliveries. The final study population included 596 women who delivered by vacuum extraction.
  
  
  RESULTS
  There was no correlation between the management of the vacuum extraction and risk for anal sphincter tear. Women from Africa had nearly a fourfold risk for anal sphincter tear during vacuum-assisted delivery compared with Swedish-born women (OR 3.82 CI 1.47-9.89). Compared with infants with birth weight less than 4000 g, birth weight above 4000 g was associated with increased risk of AST (OR 1.87 CI 1.06-3.28).
  
  
  CONCLUSIONS
  In this study, the obstetric management in VE-assisted deliveries did not impact the risk of AST.
authors: Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.
authors: P
authors: P
authors: Ryman
authors: Department of Women's and Children's Health, Division of Reproductive Health, Karolinska Institutet, Stockholm, Sweden.
authors: M
authors: M
authors: Ahlberg
authors: Department of Women's and Children's Health, Division of Reproductive Health, Karolinska Institutet, Stockholm, Sweden. Electronic address: cecilia.ekeus@ki.se.
authors: C
authors: C
authors: Ekéus
mesh_terms: D000293:Adolescent; D000328:Adult; D001003:Anal Canal / Q000293:injuries*; D001724:Birth Weight; D044383:Black People / Q000706:statistics & numerical data; D006801:Humans; D022125:Lacerations / Q000453:epidemiology* / Q000208:ethnology / Q000209:etiology; D015995:Prevalence; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D014620:Vacuum Extraction, Obstetrical / Q000009:adverse effects / Q000379:methods*; D044465:White People / Q000706:statistics & numerical data; D055815:Young Adult
keywords: Anal sphincter tear; Delivery; Vacuum extraction